Airworthiness and Safety Validation Verification Methods in A380 Program
Content
AIRWORTHINESS AND SAFETY VALIDATION VERIFICATION METHODS IN A380 PROGRAM
STUDENT NAME: IBRAHIM AL NAJJAR STUDENT NUMBER: S3158405 ACADEMIC SUPERVISOR: DR. HE REN
SCHOOL OF AEROSPACE, MECHANICAL AND MANUFACTURING ENGINEERING
Abstract
Nowadays aerospace and aviation industry is expanding very rapidly to fill the gaps of consumers' needs, as the industry expand, problems would also increase due to the high demand that would lead companies to increase their line of production where it will also increase the percentage of errors in production due to lack of time. Aerospace and aviation organizations and authorities sets certain rules and regulation to minimize errors from happening even before reaching the production line, It begin from a concept design of an aircraft as it is a synthesis of different disciplines like aerodynamics, flight mechanics, aeronautical structures, etc. Allowing Airbus A380 to be operational in normal air traffic, it is necessary to demonstrate that its design and construction are in compliance with the applicable requirements; the verification of such compliance is entrusted to the competent authorities. Airworthiness introduce aerospace engineers into a world consisting on one hand into the aircraft's designing, manufacturing and operation firms and on the other hand into airworthiness authorities, both hand should work together and they should aim at a common goal "Flight safety". Airbus A380 is the new latest and largest civil aircraft in the aviation market. This type has a novel or unusual design features when it’s compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. Many of these novel or usual design features are associated with the complex system and the configuration of the airplane. For these design features, the applicable airworthiness regulations do not contain adequate or appropriate safety standards. My thesis is to achieve an understanding of the fundamental process of Airworthiness and Safety Validation Verification Methods in A380 Program and to identify and investigate the main reasons of failure in this aircraft and how would we be able to certify it and make is free to fly, so we can use the FAA airworthiness regulation and update it so it can meet our new A380 airworthiness requirement.
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Declaration
I certify that except where due acknowledgement has been made, the work is that of the author alone; the work has not been submitted previously, in whole or in part, to qualify for any other academic award; the content of the thesis is the result of work which has been carried out since the official commencement date of the approved research program; any editorial work, paid or unpaid, carried out by a third party is acknowledged; and, ethics procedures and guidelines have been followed.
Ibrahim Al Najjar 25/10/2010
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Acknowledgement
Foremost, I would like to express my sincere gratitude to my supervisor Dr. He Ren for the continuous support of my final year project work, for his patience, motivation, enthusiasm, and immense knowledge. His guidance helped me in all the time of research and writing of this thesis. Besides my supervisor, I would like to thank Airbus, for their help, support while some information was taken from them and insightful comments. My sincere thanks also goes to Emirates Airlines for offering me the summer internship opportunities in their A380 facility, leading me working on diverse exciting project. In this project, I’ve tried my best to collect information and data from every single string related but it may still be lacking information due to unfound source or confidential information. Last but not the least; I would like to thank my family members, for supporting me and because of them I ended up taking aerospace engineer as a career.
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List of Figures and tables
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. International Civil Aviation Organization Logo http://www.whatsonxiamen.com/news_images/3345icao.jpg CAA Logo http://www.flightline.co.uk/travelnews/wp-content/uploads/2007/11/caa_logo_small.gif Joint Aviation Authorities Logo http://www.ifalda.org/Images/Organization%20Logo%20Folder/JAA%20Logo.jpg European Aviation Safety Agency Logo http://www.umcntp.co.id/images/logo/EASA_EU.png Federal Aviation Administration Logo http://servus.cocolog-nifty.com/blog/images/2008/10/10/0409faa_logo.jpg Current Technology on A380 Engine http://www.enginealliance.com/images/gpintro_05.gif Validation and Verification Method http://www.buzzle.com/editorials/4-5-2005-68117.asp Airbus A380 Parts Assembly Early Stage of A380 as A3XX http://timeforflight.tripod.com/000056.gif Airliners Order of A380 http://en.wikipedia.org/wiki/List_of_Airbus_A380_orders_and_deliveries A380 Dimensions http://www.airbus.com/en/aircraftfamilies/a380/a380/specifications/ A380 Basic Operating Data http://www.airbus.com/en/aircraftfamilies/a380/a380/specifications/ A380 Design Weights http://www.airbus.com/en/aircraftfamilies/a380/a380/specifications/ A380 External Dimensions http://www.hudihudi.com/goodones/airbus/airbusdesign.jpg Landing Gear Systems Testing http://i15.photobucket.com/albums/a357/thezeke/A380%20systems/bea0715e.png The Body Wheel Steering http://i15.photobucket.com/albums/a357/thezeke/A380%20systems/0168becd.png A380 Landing Status http://i15.photobucket.com/albums/a357/thezeke/A380%20systems/94415de2.png A380 Section 19 Systems Integration and Assembly http://www.aint.com/images/a380_dscn0915.jpg A380 GP7200 Cutaway http://turbofanatic.com/hosting/ljpictures/randompics/gp7000_cutaway_high.jpg Inside an Airbus A380 while at testing http://c0170351.cdn.cloudfiles.rackspacecloud.com/72_14_m.jpg Airbus A380 wing test http://www.flightglobal.com/assets/getAsset.aspx?ItemID=11513 Celebrating A380 http://www.skycontrol.net/UserFiles/Image/BusinessGA_img/200612/200612airbus-A380-iso.jpg A380 Landing Gear http://cdn-www.airliners.net/aviation-photos/middle/2/5/6/0965652.jpg Landing Gear at testing stage http://images.smh.com.au/2009/04/08/467150/Airbus-Landing-Gear-600x400.jpg A380 Structure http://borithlong.files.wordpress.com/2009/09/airbus-a380-11.jpg Engine examine and testing http://www.airportkosice.sk/image/image_gallery?img_id=865 A380 hydraulic unit http://www.messier-bugatti.com/IMG/jpg/hs0013nblocorient_ra_a380-230-2.jpg A380 break manifolds http://www.messier-bugatti.com/IMG/jpg/hf0041n.jpg A380 Skinless http://static.photo.net/attachments/bboard/00C/00Cpe5-24598184.jpg A380 Taxing http://www.machtres.com/ab380-006.jpg V & V Process http://www.buzzle.com/editorials/4-5-2005-68117.asp V & V Process http://www.informatik.uni-bremen.de/~tsio/papers/icstest2005_ott_hartmann-abstract.pdf A380 gear’s arrangement http://bp0.blogger.com/_JAPZLIogqvA/R3I4a1HtzPI/AAAAAAAAAIQ/yqCWY8eE2WM/s400/A380_wheel.gif A380 Extension/Retraction System http://ic2.pbase.com/g3/36/640536/2/88941012.duDJRdzS.jpg Wheel and Brake System Integrated Components http://www.messier-bugatti.com/IMG/jpg/freinelec1.jpg A380 Wheels, tires and brakes http://cdn-www.airliners.net/aviation-photos/middle/2/5/6/0965652.jpg Nose landing gear drawing http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_06_05_LandingGear.pdf Nose landing gear parts http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_06_05_LandingGear.pdf Nose Wheel Steering NWS http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_06_05_LandingGear.pdf Six-wheel landing gear system weighs approximately 12.000 pounds and is more than 25 feet long when fully extended http://www.sandvmag.com/downloads/0811obse.pdf The major mode shapes extracted from the test data were used to verify finite-element landing gear models at Goodrich and supported structural investigations at Airbus http://www.lmsintl.com/download.asp?id=9D8D8D1727E5-4C2A-9E06-90B780FF5C92 Selecting the modes of landing Gear http://www.lmsintl.com/download.asp?id=9D8D8D17-27E5-4C2A-9E0690B780FF5C92
42.
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43. Supporting landing gear and full aircraft simulations http://www.lmsintl.com/download.asp?id=9D8D8D17-27E54C2A-9E06-90B780FF5C92 44. Highly accelerated lift testing (HALT) http://www.geaviationsystems.com/About/Technical-Papers/Literature/A380landing-gear-extension-and-retraction.pdf 45. Three A380 electromechanical uplocks http://www.geaviationsystems.com/About/Technical-Papers/Literature/A380landing-gear-extension-and-retraction.pdf 46. A380 Hydraulic unit and brake manifolds http://www.messier-bugatti.com/article.php3?id_article=321%20&lang=en 47. A380 BTMS & TPMS http://www.messier-bugatti.com/rubrique.php3?id_rubrique=60&lang=en 48. Trent 900 Cutaway http://www.nickelinstitute.org/multimedia/magazine/March_2007/Turbines/Trent-900-cutaway600.jpg 49. Trent 900 Bird Strike Testing http://www.rolls-royce.com/Images/whittle_tcm92-5495.pdf 50. Trent 900 water ingestion test http://i14.tinypic.com/42sthxk.jpg 51. A380 Testing in hot weather conditions http://gulfnews.com/polopoly_fs/26-bz-airbusa3801-5-jpg1.258406!image/1840445697._gen/derivatives/box_475/1840445697. 52. Trent 900 bird strike test http://www.investis.com/rollsroyce/presentations/numis.pdf 53. Trent 900 water ingestion test http://i.ytimg.com/vi/faDWFwDy8-U/0.jpg 54. Tent 900 EMU http://www.ipl.com/pdf/pc022.pdf 55. Trent 900 fan blade-off test http://www.investis.com/rollsroyce/presentations/numis.pdf 56. Engine Alliance GP7200 http://australianaviation.com.au/wp-content/uploads/2010/08/article5-image1-full.jpg 57. Final assembly of the first GP7200 http://www.enginealliance.com/images/030404_11.jpg 58. Engine Alliance GP7200 FETT http://www.enginealliance.com/images/040604_12.jpg 59. GP7200 engine is undergoing extensive testing at GE’s Peebles Test Operation in Ohio http://www.sae.org/aeromag/techfocus/02-2005/2-25-1-18.pdf 60. Pratt & Whitney's full-scale Geared Turbofan demonstrator engine during a nacelle system fit check http://www.pw.utc.com/StaticFiles/Pratt%20&%20Whitney/News/Press%20Releases/Assets/Images/gtf-nacelle-fitcheck.jpg 61. GP7200 Tested at AEDC and icing test http://www.arnold.af.mil/photos/mediagallery.asp?galleryID=4551 62. Engine Alliance Delivers First A380 Engines to Airbus http://www.enginealliance.com/images/img_092905.jpg 63. GP7200-powered A380 Receives FAA, EASA Type Certifications http://www.enginealliance.com/release121407.html 64. A380 5000 PSI hydraulic system http://www.sae.org/dlymagazineimages/6728_6751_ART.jpg 65. EHA mini-pumps for A380 flight control: ailerons, rudder and elevator http://www.messier-bugatti.com/IMG/jpg/hmp0033n.jpg 66. Hydraulic system block diagram http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 67. Eaton’s Airbus A380 Components http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 68. Engine Driven Pump http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 69. AC Motor Pump http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 70. Fire Shut-Off Valve (FSOV) http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 71. A380 nose wheel steering AMESim simulation/test bench results comparison AMESim model matches real system behaviour. http://www.lmsintl.com/download.asp?id=0FAEE181-15EB-4854-B1FF-D4AB47191AFA 72. Local Electro Hydraulic Generation System (LEHGS) with its Electronic Control Unit (ECU) http://www.lmsintl.com/download.asp?id=0FAEE181-15EB-4854-B1FF-D4AB47191AFA
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73. Thermal chambers test Airbus hydraulic systems http://www.carbolite.com/imagelib/fr_hightemp.jpg 74. A380 Fatigue test http://www.iabg.de/presse/download/bilder/highres/IABG_Versuchsaufbau_Airbus_A380_5-1024.jpg 75. The whiffle tree structure used to do a torsion test http://www.diomedes.co.za/pics/gallery/TestTubeTorsionSetup1.jpg 76. Typical A380 cabin configuration http://biztravelguru.com/blogs/business-travel-news/Qantas-A380-Seat-map-released.jpg 77. Emirates A380 First-Class private suites http://content.emirates.com/english/images/First%20Class%20Private%20Suites_media_545x320_12_tcm233354372.jpg 78. Setup for the Spoiler Test of the Airbus A380 http://www.iabg.de/presse/aktuelles/mitteilungen/images/200504_Airbus_A380_Spoiler_Test-1024.jpg 79. Airbus has been running load trials on a full scale A380 static test specimen in Toulouse since late 2004 http://www.flightglobal.com/assets/getAsset.aspx?ItemID=11513 80. Airbus performing bending test on A380 wing http://www.flightglobal.com/assets/getAsset.aspx?ItemID=11514 81. A380 FE wing model http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_01_30_A380.pdf 82. A380 Super Jumbo Jet Makes Maiden Flight http://www.dancewithshadows.com/business/images/a380/airbus-first-flight7.JPG 83. A380 Crosswind landing test http://fliiby.com/images/_thumbs/me_ovftb99fdv1.jpg 84. A380 during hot weather testing http://www.chinadaily.com.cn/cndy/attachement/jpg/site1/20100915/002564baf2f90dfa5a2f4a.jpg 85. A380 during cold weather testing http://www.puddy.co.uk/golf/DSC00201.jpg 86. A380 Route proving http://www.globalgiants.com/archives/2007/04/the_a380_makes.html 87. A380 CFD model http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_01_30_A380.pdf
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Table of Content
Abstract…………………………………………………………………………………………………………………………….………..…I Declaration……………………………………………………………………………………………………………………….………….II Acknowledgement……………………………………………………………………………………………………………………...III List of Figures and Tables…………………………………………………………………………………………………………….IV 1. Introduction………………………………………………………………………………………………………………………………….1
1.1. Flight Safety………………………………………………………………………………………………………………………………………………1 1.2. Airworthiness……………………………………………………………………………………………………………………………………………2
2. Airworthiness Organization and Authorities……………………………………………………………………………….…4
2.1. 2.2. 2.3. 2.4. 2.5. The ICAO (International Civil Aviation Organization)…………………………………………………………………………………4 The CAA (Civil Aviation Authorities)……………………………………………………………………………………………..……………4 The JAA (Joint Aviation Authorities)……………………………………………………………………………………………,…………….4 The EASA (European Aviation Safety Agency)……………………………………………………………………………………………4 The FAA (Federal Aviation Administration)……………………………………………………………………………………………….5
3. Literature Review.………………………………………………………………………………………………………………………..6
3.1. Review…………………………………………………………………………………………………………………………………..………………….6
4. A380 Concept Model History…………………………………………………………………………………………………….….8
4.1. Concept Model……………………………………………………………………………………………………………………………………….…8
5. Airbus A380………………………………………………………………………………………………………………………………….9
5.1. A380………………………………………………………………………………………………………………………………………………………...9 5.1.1. Aircraft Dimensions……………………………………………………………………………………………………………………….10 5.1.2. Basic Operating Data…………………………………………………………………………………………………………………….10 5.1.3. Design Weights………………………………………………………………………….………………………………………………….10 5.2. Landing gear System……………………………………………………………………………………………………………………………….11 5.3. Brake and Steering System………………………………………………………………………………….………………………………….12 5.4. Structural Design…………………………………………………………………………………………………………………………………….14 5.5. Powerplant………………………………………………………………………………………………………………….………………………….15
6. A380 Tests and Certification……………………………………………………………………………………………………….16
6.1. Overview………………………………………………………………………………………………………………………..……………………….16
7. A380 Type Certificate………………………………………………………………………………………………………………….17
7.1. Obtaining Type Certificate………………………………………………………………………………..………………………...………….17 7.2. A380 Type Certificate………………………………………………………………………………………………………………………………17 7.3. A380 Preparation testing for Type Certificate………………………………………………………………………………………….17
8. Federal Aviation Administration……………………………………………………………………………………………….…19
8.1. Background…………………………………………………………………………………………………………………………………………….19
9. Federal Aviation Administration (FAR 25: Landing gear)………………………………………………………….….20
9.1. 9.2. 9.3. 9.4. 9.5. 9.6. 25.721 – General………………………………………………………………………………………………………..……………………….….20 25.723 - Shock absorption tests………………………………………………………………………………..…………………………….20 25.731 – Wheels……………………………………………………………………………………………………………………………………..20 25.733 – Tires……………………………………………………………………………………………………………………………………….…20 25.735 - Brakes and braking systems……………………………………………………………………………………..……………….21 25.737 – Skis……………………………………………………………………………………………………………………....………………….21
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9.7. 25.487 - Rebounding landing condition……………………………………………………………………………………….………….21 9.8. 25.1515 - Landing gear speeds…………………………………………………………………………………………………….………….21 9.9. 25.729 - Landing gear extension and retraction system………………………………………………………………………….22
10. Federal Aviation Administration (FAR 25: Structural and Design) ……………………………..…………….….23
10.1. 10.2. 10.3. 10.4. 10.5. 10.6. 10.7. 10.8. 25.303 - Factor of safety………………………………………………………………………………………………………………….…….23 25.307 - Proof of structure……………………………………………………………………………………………………………….…….23 25.341 – Gust and turbulence loads…………………………………………..…………………………………………………….…….23 25.523 - Design weights and center of gravity positions….……………………………………………………………….…….23 25.603 – Materials……………………………………………………………………………………………………………………….….…….23 25.631 - Bird strike damage…………………………………………………………………………………………………………….…….24 25.681 - Limit load static tests………………………………………………………………………………………………..……….…….24 25.843 - Tests for pressurized cabins……………………………………………………………………………………………….…….24
11. Federal Aviation Administration (FAR 25: Powerplant) …………………………………………………..………….25
11.1. 25.903 – Engines………………………………………………………………………………………………………………….………………..25 11.2. 25.939 - Turbine engine operating characteristics………………………………………………………………………..….…….25 11.3. 25.963 - Fuel tanks: general…………………………………………………………………………………………………………….…….25 11.4. 25.1125 - Exhaust heat exchangers……………………………………………………………………………..………………….…….25 11.5. 25.1141 - Power plant controls: general……………………………………….……………………………………….……………….26 11.6. 25.1203 - Fire detector system……………………………………………..………………………………………………………….…….26 11.7. 33.76 - Bird ingestion……………………………………………………………………………………………………………………….…….26 11.8. 33.83 - Vibration test……………………………………………………………………………………………………………..…………..….27 11.9. 33.88 - Engine over temperature test…………………………………………………………………………………..………….…….27 11.10. 33.94 - Blade containment and rotor unbalance tests………………………………………………………….…….27
12. Federal Aviation Administration (FAR 25: Hydraulic System)…………………………………………………….…28
12.1. 25.1435 - Hydraulic System………………………………………………………………………………………………………….….…….28 12.1.1. Element design…………………………………………………………………………………………………………………….…….28 12.1.2. System design………………………………………………………………………………………………………………….……..….28 12.1.3. Tests…………………………………………………………………………………………………………………………………….…….28 12.2. A380 Hydraulic System…………………………………………………………………………………………………………………….…….29
13. Special Conditions (FAR 25: Structural and Design)……………………………………………………………………..30
13.1. 13.2. 13.3. 13.4. 13.5. Airbus Model A380-800 Airplane, Crashworthiness………………………………………………………………………….…….30 Airbus Model A380-800 Airplane, Airplane Jacking Loads……………………………………………….……………….…….30 Airbus Model A380-800 Airplane, Transient Engine Failure Loads………………………………………………………….31 Airbus Model A380-800 Airplane, Reinforced Flight deck Bulkhead………………………………………………….…….32 Airbus Model A380-800 Airplane; Fire Protection…………………………………………………………………………….…….32
14. Special Conditions (FAR 25: Landing Gear)…………………………………………………………………………………..33
14.1. Airbus Model A380-800 Airplane; Loading Conditions for Multi-Leg Landing Gear………………………………...33 14.2. Airbus Model A380-800 Airplane, Ground Turning Loads……………………………………………………………………….34
15. Verification and Validation Process (V & V)……………………………………….………………………………..………35
15.1. Verification……………………………………………………………………………………………………………………………………………..36 15.2. Validation……………………………………………………………………………………………………………………………………………...38
16. Landing Gear, Brake, and Steering System…………………………………………………………………………………..40
16.1. Equipment Tests…………………………………………………………………………………………………………………………………………………..42 16.1.1. Nose Landing Gear……………………………………………………………………………………………………………………..42 16.1.2. Main Landing Gear……………………………………………………………………………………………………………………..44
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16.1.3. Landing Gear Extension and Retraction System………………………………………………………………………….48 16.1.4. Brake and Steering System…………………………………………………………………………………………………………50 16.1.4.1. Braking Control System…………………………………………………………………………..……………………50 16.1.4.2. Steering System……………………………………………………………………………………………………………51 16.1.4.3. Tire, Brake and Landing Gear Monitoring Systems ………………………………………………………51
17. Powerplant…………………………………………………………………………………………………………………………………52
17.1. Rolls-Royce Trent 900……………………………………………………………………………………………………………………………..52 17.1.1. Equipment Tests…………………………………………………………………………………………………………………………54 17.1.2. Qualification Tests……………………………………………………………………………………………………………………..56 17.1.2.1. Bird Ingestion (FAR section 33.76)………………………………………………………………………………..56 17.1.2.2. Rain and Hail Ingestion (FAR section 33.78)………………………………………………………………….56 17.1.2.3. Vibration Test (FAR section 33.83)………………………………………………………………………………..57 17.1.2.4. Endurance Test (FAR section 33.87)……………………………………………………………………………..57 17.1.2.5. Engine Over Temperature Test (FAR section 33.88)………………………………………………………57 17.1.2.6. Blade Containment Rotor Unbalance Tests (FAR section 33.94)……………………………………58 17.2. Engine Alliance GP7200…………………………………………………………………………………………………………………………..59 17.2.1. Equipment Tests…………………………………………………………………………………………………………………………60 17.2.2. Qualification Tests………………………………………………………………………………………………………………………65 17.2.2.1. Bird Ingestion (FAR section 33.76)………………………………………………………………………………..65 17.2.2.2. Rain and Hail Ingestion (FAR section 33.78)………………………………………………………………….65 17.2.2.3. Vibration Test (FAR section 33.83)………………………………………………………………………………..66 17.2.2.4. Endurance Test (FAR section 33.87)………………………………………………………………………………66 17.2.2.5. Engine Over Temperature Test (FAR section 33.88)………………………………………………………66 17.2.2.6. Blade Containment Rotor Unbalance Tests (FAR section 33.94)……………………………..…….66
18. Hydraulic System………………………………………………………………………………………………………………………..67
18.1. Equipment Tests……………………………………………………………………………………………………………………………………..69 18.1.1. Eaton Corporation………………………………………………………………………………………………………………………69 18.1.1.1. Engine Driven Pump……………………………………………………………………………………………………..71 18.1.1.2. AC Motor Pump……………………………………………………………………………………………………………71 18.1.1.3. Fire Shut-Off Valve (FSOV)…………………………………………………………………………………………….72 18.1.2. Messier-Bugatti………………………………………………………………………………………………………………………….73 18.1.3.FR-HiTEMP……………………………………………………………………………………………………………………………………..74
19. Structural and Design………………………………………………………………………………………………………………….75
19.1. Ground Tests…………………………………………………………………………………………………………………………………………..75 19.1.1. Fatigue Tests………………………………………………………………………………………………………………………………75 19.1.2. Cabin Tests…………………………………………………………………………………………………………………………………77 19.1.3. Wing Tests………………………………………………………………………………………………………………………………….79
20. Flight Tests………………………………………………………………………………………………………………………………….82
20.1. MSN 001…………………………………………………………………………………………………………………………………………………83 20.2. MSN 002…………………………………………………………………………………………………………………………………………………83 20.3. MSN 004…………………………………………………………………………………………………………………………………………………84
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20.4. MSN 007…………………………………………………………………………………………………………………………………………………84 20.5. MSN 009…………………………………………………………………………………………………………………………………………………84 20.6. Crosswind Landing Flight Test…………………………………………………………………………………………………………………85 20.7. Natural Gas as a Fuel Alternative……………………………………………………………………………………………………………85 20.8. High Altitude and Hot Weather Testing…………………………………………………………………………………………………..85 20.9. Cold Weather Trails…………………………………………………………………………………………………………………………………86
21. Route Proving……………………………………………………………………………………………………………………………..87 22. Conclusion and Recommendations……………………………………………………………………………………………..89 23. Reference……………………………………………………………………………………………………………………………………90
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1. Introduction
Nowadays aerospace and aviation industries are expanding very quickly and rapidly to fill the gaps of consumers' needs, so as the industry expand, problems would also become big and bigger because of the high demand that would lead companies to increase their line of production and that obviously increase the percentage of errors and accidents in production due to lack of time but thanks to the aerospace and aviation organizations and authorities that set certain rules and regulation to minimize errors from happening even before the reaching the production line, It starts from the design of an aircraft as it is a synthesis of different disciplines like aerodynamics, flight mechanics, aeronautical structures, etc. Allowing as aircraft to be operational in normal air traffic, it is necessary to demonstrate that its design and construction are in compliance with the applicable requirements; the verification of such compliance is entrusted to the competent authorities. Airworthiness introduce aerospace engineers into a world consisting of one hand into the aircraft's designing, manufacturing and operation firms and on the other hand into airworthiness authorities, both hand should work together and they should aim at a common goal "Flight safety".
1.1. Flight Safety
Safety is a concept generally ingrained in the human mind; we will consider 'absence of danger' as its principal definition. Safety is something related to all human activities and therefore every civil society is organized (or should be organized) to guarantee public safety in relation to one's own or others' activities. This is certainly a moral obligation, but it is also a practical demand because accidents, causing damage to persons and properties, have a social cost. This is also the reason why human activities that could cause damage to persons and properties are controlled by national states through regulations. We will deal specifically with safety related to aeronautical activities, starting by considering what we have defined as the main conventional flight safety factors: man, the environment and the machine. 1. Man is intended here as an active part of the flight operations; we then consider pilots, maintenance manpower, air traffic controllers, and others. Clearly, it is important to be able to rely on very skilled people in order to avoid errors that cause accidents or catastrophes in flight operations. It is then of paramount importance to place these people in a legislative and organized context to guarantee a suitable level of professional training updating of techniques and procedures and psychological and physical fitness National states entrust special public institutions with the responsibility for such obligations.
2. The environment covers all the external factors that can have an influence on the flying of an aircraft. This includes meteorological conditions, traffic situations, communications, aerodromes, etc. It is equally important to avoid situations that could jeopardize the aircraft itself. Then we should consider correct meteorological information, rules for the vertical and
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horizontal separation of the aircraft, suitable aerodromes, etc. 3. The machine does not need a definition, but it is easy to understand the importance of a good project, sound construction, and efficiency in relation to the operations to be carried out. Also, in this case, national states entrust special public bodies with the responsibility of assuring that the project, the construction, and the operating instructions comply with flight safety. An important point regarding these safety factors is that they act in series and not in parallel. They can be seen as three links of a chain representing flight safety. The failure of a single link is sufficient for an accident to happen. A pilot's error can put the best aircraft in jeopardy, and the best pilot cannot compensate for a serious failure in an aircraft. Accident reports offer countless examples of this; however, accidents are often caused by a combination of factors that could involve all these safety factors. Nevertheless, the accident always begins with the failure of one of the above mentioned links.
1.2. Airworthiness
A definition of 'airworthiness' can be found in the Italian RAI-ENAC Technical Regulations: 'for an aircraft, or aircraft part, [airworthiness] is the possession of the necessary requirements for flying in safe conditions, within allowable limits.' In this definition, three key elements deserve special consideration: safe conditions, possession of the necessary requirements, and allowable limits. 1. We can take for granted the meaning of safe conditions relating to the normal course and satisfactory conclusion of the flight. According to one definition, safety is the freedom from those conditions that can cause death, injury or illness, damage to/loss of equipment or property, or damage to the environment.
2. Possession of the necessary requirements means that the aircraft, or any of its parts, is designed and built according to studied and tested criteria to fly in safe conditions, as mentioned above. Regulations are intended to promote safety by eliminating or mitigating conditions that can cause death, injury, or damage. Who establishes these regulations? The airworthiness authorities appointed by the national states. These are obtained through the publication of airworthiness standards containing a series of design requirements: from the strength of the structure to the flight requirements like flight qualities and performance, criteria for good design practice, systems, fatigue and flutter, necessary tests, flight and maintenance manual content, and so on. These standards are different for different types of aircraft. Obviously, it is not possible to design a sailplane, a 'Jumbo', or a helicopter using the same rules. An important peculiarity of these standards is their evolution as time passes. Generally, a standard does not precede aeronautical progress; it follows it and sometimes accompanies it. A 'blocked' standard would prevent aeronautical progress. It follows that the rules have to continuously fit with technical aeronautical evolution.
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Moreover, very often accident analysis leads to additional rules which, had they been applied to the design might have prevented the accident or at least limited its effects; this process could be regarded as 'afterthoughts', but it is better to consider it as 'experience'. The changing of the standards like normally with the purpose of adding something new or different would make the design compliance to the rules more and more expensive, but this is the price to pay to improve flight safety.
3. Allowable limits. Aircraft are designed for operation within a certain 'flight envelope', which depends mainly on speed and structural load factors. In addition, the maximum weight of the aircraft can be established differently for different types of operations. Operational conditions of the aircraft, such as day-VFR, night flight, instrumental flight, in or out of icing conditions, etc., are also established. Exceeding these conditions and limits can cause accidents. Overweight take-off, aerobatic maneuvers performed with aircraft designed with load factors for nonaerobatic operations, flights in icing conditions without suitable protection, and exceeding the speed limits are just few examples of the importance of flying within the allowable limits. Pilots are made aware of these limits through the flight manual, through the markings and placards displayed in the cockpit, and of course through training.
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2. Airworthiness Organization and Authorities
The aerospace and aviation industry is controlled by rules and regulation to restrict firms from designing or manufacturing parts that would lead to disasters, there are different of organization and authorities that set these rules and every organization has a different task but all meet at one approach is Airworthiness of aircrafts and part. Here is a list of some airworthiness organization and authorities and their task:
2.1. ICAO (International Civil Aviation Organization)
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The aims and objective of the ICAO are to develop the principle and techniques of international air navigation and to foster the planning and development of international air transport.
2.2. CAA (Civil Aviation Authorities)
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It's an airworthiness authority that has four tasks:
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Prescribe airworthiness requirements and procedures. Inform the interested parties regarding airworthiness prescription. Control aeronautical material, design, manufacturing organizations, and aircraft operators. Certificate aeronautical materials and organization.
2.3. JAA (Joint Aviation Authorities)
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The aim is to develop a harmonized airworthiness standards to meet the needs of the industry in Europe, particularly for products manufactured by international consortia, also to operations, maintenance, and licensing and certification design standards for all classes of aircraft.
2.4. The EASA (European Aviation Safety Agency)
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The aim of this agency is to assist European commission in preparing legislation, and support the member states and industry in putting the legislation into effect also to monitor the application of European community legislation. It also adopts its own certification specification and guidance material, conducts technical inspections, and issue certification where centralized action is more efficient.
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2.5. The FAA (Federal Aviation Administration)
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The FAA is responsible for the safety of civil aviation. Its main roles include:
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Regulating civil aviation to promote safety. Encouraging and developing civil aeronautics, including new aviation technology. Developing and operating a system of air traffic control and navigation for both civil and military aircraft. Researching and developing the national airspace system and civil aeronautics. Developing and carrying out programs to control aircraft noise and other environmental effects of civil aviation. Regulating US commercial transportation.
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3. Literature Review
3.1. Review
The A380 is the leader of aircrafts in 21st century, which falls into this category of very large aircraft; it can carry up to 800 passengers and has a maximum take-off weight (MTOW) of about 560 tons. A380 is not only the largest civilian aircraft ever, but is also more a combination of advanced technology in all aspects of aircraft engineering. With advanced technology that will make a step forward in the economics of operating, must also be an opportunity to be taken to ensure that this technology works the same for maintenance purposes. It is clear that the availability of aircraft, in terms of operational reliability, maintenance down time and maintenance cost are critical factors in the success of this particular aircraft, and therefore taken into account at the same level as the more traditional design objectives. The main objective of the maintenance is to clear and maintain the highest levels of airworthiness, but this does not conflict with the requirement to achieve very high availability of aircraft in operation costs to a minimum. The main goal of reliability of the A380 is much higher than the target was on the Airbus A340 series, which is 99% within two years of entry into service. It is clear that when a very large aircraft (VLA) such as the A380 gets bigger and longer-term and get, is more difficult to meet the airworthiness requirements set by authorities. Therefore, the FAA and EASA standards and requirements are placed on top of the list of priorities in the design of A380. Airworthiness requirements must be consistent with the objectives of maintenance, costs and the policy challenge is to put targets on the A380 equipment suppliers, especially for items that are undergo testing. Airworthiness is required from systems and component to test reliability because obviously critical factors in the early achievement of aircraft maturity and maturity assurance is planned through the design ‘Validation and verification’ (V&V) process and the introduction of intensive accelerated reliability testing to ‘shake out the bugs’ early enough so they can be fixed before entry into service. Aircraft level safety process was implemented for the first time on a large-scale commercial aircraft. It identifies aircraft level functions and associated failure conditions, decomposes them to multiple systems and places requirements on various levels of suppliers in the development of system and equipment. It has been shown that the outcome of the V&V process is the important basis on which all the critical engineering decisions to be made. In order to certify A380, Airbus’s engineers, working with the European Aviation Safety Agency and the FAA, reviewing any structural failure and determined what engineering changes must be made to the structure before the design can be certified. This paper presents the basic knowledge and methodology of V&V process including the objectives and framework. The implementation of V&V method in A380 safety process is discussed with the details of various analyses relating to this process. Lastly, this paper shows the example of how engine alliance applied V&V methodology in designing the GP7200 engine for A380 aircraft.
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4. A380 Concept Model History
4.1. Concept Model
The first A380 concept model was named A3XX with 49% more floor space than a jumbo jet but it had one huge problem in delivery of A3XX giant parts with Airbus Super Transporter (Beluga), in fact the A3XX was so massive that fuselage parts couldn’t be carried or fitted on the Beluga (Airbus largest cargo aircraft) which made Airbus reconsider their project plan for next generation super passenger carrier A3XX and look deeply to modify the shape to look into something completely different.
Part Fuselage Floor Beams Tail Section Wings Tail Fin Landing Gear Production Country Hamburg– Germany Tokyo–Japan Madrid–Spain Wales– United Kingdom Hamburg– Germany Toronto– Canada
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Airbus team ever studied currying A3XX wing biggie back style on other plane but after wind tunnel testing they decided the aerodynamics is too risky. Airbus head of transportation looked at ways to help rebirth the A3XX and came with a divided assistant system to transport aircraft parts by roads, rivers, and sea in a logistical dance that has to fit to together perfectly and work for first time. The fuselage, wing and tail planes will set off by sea by factories in Germany, Wales, France and Spain, converging on port of Bouc on the west coast of France where from there they will be loaded into barges that will carry them 59 miles to the river Dordogne and still the journey is not complete, a fleet of lorry will hold the parts by road to last 150 miles to Toulouse, this long process is under the supervision of Airbus’s Head of logistics where he has to coordinate the schedule.
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5. Airbus A380
5.1. A380
The project of making the world largest aircraft eclipsing Boeing's 747 was established by Airbus Company which is the competitor of Boeing Company. Airbus first began to study a very large 500 seats aircraft in the early 1990s. The success of Boeing 747 was the inspiration that made Airbus Company developed this aircraft as a strategy to collapse Boeing's dominance of the very large airliner market. In June 1994, engineering designer began their work on the A3xx. At that time, Airbus Company extremely interested to a single deck aircraft which would have 12 abreast and twin vertical tails. Nevertheless, Airbus decided to choose a twin deck configuration due to the requirement of lighter aircraft structure. There are 3 main proposes to design Airbus A380 which are that the ability to use existing airport infrastructure with little modifications to the airports, direct operating costs per seat 15-20% less than those for the B747 including provide more floor space, and lastly, Airbus prefers to make wider seats and aisles for the comfortable of passengers. Moreover, the most latest and advanced technologies are used in this aircraft considering lower fuel burn and emissions, and noise reduction. The 555 seats, double deck Airbus A380 entered service in March 2006. There are several models of A380. The basic aircraft is the 555 seats A380-800 and high gross weight A380-800, with the longer range A380-800R. The A380-800F freighter will be able to carry a 150 tones payload which dues to enter service in 2008. The A380700 is the future model with shortened 480 seats and the stretched 656 seats A380-900. Customer Air France Air Austral British Airways China Southern Emirates Etihad Airways ILFC Kingfisher Airlines Korean Air Lufthansa Malaysia Airlines Qantas Qatar Airways Singapore Airlines Thai Airways International Virgin Atlantic Prince Al-Walid A380-800 12 2 12 5 90 10 10 5 10 15 6 20 5 19 6 6 1 234
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Total Although A380 is not enter fully service, there are many airlines order the most ambitious civil aircraft. The following table shows the number of aircraft which each airline orders A380. (1)
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5.1.1. Aircraft Dimensions
Overall length Height Fuselage diameter Maximum cabin width
Metric 73 m. 24.1 m. 7.14 m. Main deck: 6.58 m. Upper deck: 5.92 m. 49.90 m. 79.8 m. 845 m2 33.5 degrees 30.4 m. 14.3 m.
Imperial 239 ft. 3 in. 79 ft. 7 in. 23 ft. 5 in. Main deck: 21 ft. 7 in. Upper deck: 19 ft. 5 in. 163 ft. 8 in. 261 ft. 8 in. 9,100 ft2 33.5 degrees 99 ft. 8 in. 46 ft. 11 in.
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Cabin length Wingspan (geometric) Wing area (reference) Wing sweep (25% chord) Wheel base Wheel track 5.1.2.
Basic Operating Data
Metric Engines Engine thrust range Typical passenger seating Range (w/max. passengers) Max. operating Mach number (Mmo) Bulk hold volume - Standard/option 5.1.3. Design Weights Trent 900 or GP 7000 311 kN 525 15.200 km. 0.89 Mo. 17.3 cu. m.
Imperial Trent 900 or GP 7000 70,000 lb. slst 525 8,200 nm. 0.89 Mo. 650 ft3
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Maximum ramp weight Maximum takeoff weight Maximum landing weight Maximum zero fuel weight Maximum fuel capacity Typical operating weight empty Typical volumetric payload
Ton 562 560 386 361 310.000 Liters 276.8 66.4
lb x 1000 1,239 1,235 851 796 81,890 US gal. 608.4 145.5
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5.2. Landing gear System
There are four main companies which develop the landing gear of A380 which are Goodrich, Messier-Dowty, Messier-Bugatti, and Smiths Aerospace. Each of company will develop in different part of landing gear. Firstly, Goodrich Company landing gear consists of two under wing struts each with four wheels, two central under- fuselage struts each with six wheels and a twin nose wheel. Next, Messier-Bugatti takes care about the brake and steering system of landing gear of A380. Thirdly, nose landing gear is supplied by Messier-Dowty Company with 350 bar hydraulic pressure. For landing gear extension and retraction system are supplied by Smiths Aerospace Company. The characteristic of landing gear of A380 is approximately 18 and half feet tall and a single A380 body landing gear supports about 167 tons which can hold up 2 and half Airbus A320 aircraft
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including passengers and their luggage. The main landing gear is manufactured in Canada. The major test facility is a Super Rig for structural testing which includes the strength and fatigue testing of both wing and body landing gears of A380. Good rich Company stated that "an endurance test rigs are being added to accommodate the retraction endurance test and the steering endurance testing of the body landing gear bogie beam. The drop testing of the landing gear will be performed on-site in a separate building". Moreover, the tests are conducted as in real flight operation for evaluating and analyze the most accurate response of landing gears. (2)
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5.3. Brake and Steering System
For brake and steering system, normally, in the large aircraft have three sets of redundant hydraulics which are two primary circuits and a third back-up for safety, all adding up to a big load of hefty piping. The way to reduce this mass is to replace with a decentralized fluid-power generation system on the A380. The micro which uses in A3 80 provides 5,000 psi (350 bars) of local hydraulic pressure over short runs of small-diameter light weight piping for braking and steering. There are so many challenges in optimizing system performance such as integrating and sizing the large number of different physical parts, and electrical and hydraulic systems. The solution for these challenges is to use the LMS Imagine Lab Ground Loads solution, so this solution allows engineers to investigate
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parameters and scenarios. With these capabilities, the company can simulate the behavior of the electro-hydraulic system for the A380. Moreover, the A3 80 can enter into service with this nose wheel steering system control loop only tuned with LMS Imagine Lab. (3)
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The Body Wheel Steering (BWS) is powered by the yellow hydraulic circuit. The system and controls the rear axle of the Body Landing Gear.
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A380 Landing Gear showing all wheels and brake status
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5.4. Structural Design
For many years, aircraft designers may establish many aircrafts in theoretical but they always say that they cannot become real in practice because the material which use to build the aircraft structure does not exist or cannot find. However, nowadays, composite material plays as an important role to build aircraft structure. Composites are the most significant materials that are adapted to use in aviation industry since the use of aluminum in the 1920s. The process of making composite structures is more complex than making metal structures. One useful feature of composites is that they can be layered, with the fibers in each layer running in a different direction. This can lead to aircraft designers design structures that behave in certain ways. Moreover, there are several advantages that can gain from composite material. The greatest value of composite materials is that they provide lightweight structure and strong at the same time. The lighter aircraft weighs, the less fuel consumptions, so reducing weight is the most important thing that aerospace engineers must concern. Moreover, composite material does not provide only reduction of weight but also gives an advantage in aerodynamic performance of the aircraft. Additionally, Airbus Company stated that "lower airframe weight and better aerodynamic contributed to the decrease of demands placed on engines and translate into lower fuel burn and lower operating costs". Due to composite material have many advantages when weigh to disadvantages, Airbus Company decide to choose composite material in A380 structure. Twenty-five percents of the structure of A380 made up by composites material. The rest of A380 structure made by aluminum, miscellaneous, surface protections, and titanium and steel accounting for sixty-one percents, two percents, two percents, and ten percents respectively. In twenty- five percents of the whole structure of A380 structure is composite material, can be classified into two main types which are Carbon Fiber Reinforced Plastic (CFRP) and GLARE. (4)
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5.5. Powerplant
The Airbus A380 has novel of unusual design features when compare to the current state of technology and also A380 is the biggest commercial aircraft that ever have before. There are several issues that Airbus Company and his partners need to concern. The powerplant is one of the significant issues that these companies cannot ignore. Due to the fact that A380 has a maximum takeoff weight of approximately 560 tons as shown in the A380-specifications section. Hence, the powerplant that will be used in this aircraft must have the high driving power. Rolls-Royce and General Electric Aviation and Pratt & Whitney will develop the powerplant for A380. There are two models of engine selected as the powerplant systems of the super-jumbo aircraft A380 which are:
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GP 7200 Trent 900
(5)
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6. A380 Tests and Certification
6.1. Overview
Federal Aviation Administration and European Aviation Safety Agency are so strict in their policy to certify and validate a new design aircraft, therefore airbus were required to do all type of testing on their new design aircraft to secure their business and ensure customers and FAA would be happy, so in order to certify Airbus A380, it was required to run several tests on the actual aircraft after passing all computational tests. It took airbus a long time to verify testing and ensure everything was going in the right track, due to long time testing took, it was delayed on delivery to customers. A380 attempted too many tests in different parts on world, some of these tests are: ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· Velocity Minimum Un-stick Test Rejected Take-off Test Flutter Tests High Altitude Test Cold Weather Test Hot Weather Test Evacuations Tests Velocity Minimum Control Ground Tests Technical Route Proving Crosswind Landing Test Wing Fuselage Testing Blade Off Engine Test Landing Gear Test Brake test (Overload Landing)
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7. A380 Type Certificate
7.1. Obtaining Type Certificate
The type certificate is a document by which the authority states that an applicant has demonstrated compliance of type design to all applicable requirements. This certificate is not in itself an authorization for the operation of an aircraft, which must be given by an airworthiness certificate. Obtaining type certificate is the first step of the new aircraft being successful as it meets the drawing, specification, methods of manufacturing and other data requirements. (6)
7.2. A380 Type Certificate
The European Aviation Safety Agency (EASA) issued its safety approval for the Airbus A380. The A380 is the first large European aircraft to be certified by EASA. The EASA “type-certificate” confirms that the design of the aircraft complies with European safety and environmental standards. The A380 can now be legally registered and operated commercially throughout the European Union. In addition, the type-certificate is valid in Switzerland, Norway, Iceland and Liechtenstein. At the same time, the Federal Aviation Administration (FAA) has issued its “validation” of the A380 certification for the US market. The certification process for the A380 began in 1998 with the French aviation authority and was taken over by the Agency when it started operations in 2003. A team of 42 certification specialists headed by the Agency have scrutinized the aircraft’s design involving hundreds of demonstrations and flight-tests. A major test involved 853 passengers plus crew being evacuated from the aircraft in 78 seconds, well below the required pass mark of 90 seconds. (7) The A380 certification is the first to be jointly completed by the European Aviation Safety Agency (EASA) and the U.S. Federal Aviation Administration (FAA).
7.3. A380 Preparation testing for Type Certificate
The A380 test program started with systems testing in 2001, structural testing in November 2004 and structural fatigue testing in September 2005. This then led to one of the most extensive certification flight test programs in the history of Airbus, marked with the first flight on 27th April 2005 and ending on 30th November 2006 with the successful around the globe technical routeproving trip, which took the aircraft over both poles, testing the aircraft’s performance under normal airline operations. The flight tests have been designed to assess the general handling qualities of the aircraft, operational performance, and airfield noise as well as systems operation, in normal mode, failure cases and extreme conditions. For the extreme weather trials Airbus has taken the aircraft from the cold of Northern Canada, to the desert heat of the Gulf and hot and high altitudes of Ethiopia & Colombia where it yielded excellent results and in many cases surpassed its design targets. (7)
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Further flight tests for certification purposes have been dedicated to water ingestion trials; low speed take-off tests; flutter; and rejected take off and landings. In addition to a number of wake vortex trials required for certification, Airbus has performed and continues to perform a large series of tests and measurements in this area. These tests have been designed to gather data to support recommendations by the A380 Wake Vortex Steering Group made to the International Civil Aviation Organization (ICAO), regarding safe wake vortex separation criteria for aircraft following an A380 for various flight conditions. In addition to flight test success, further highlights have included airport compatibility trials with a total of 38 airports visited to date around the globe during which the ability to operate the A380 in the same way as existing large aircraft has been demonstrated. The A380 cabin also underwent a series of tests for certification, including the successful evacuation test, performed at Airbus' Hamburg site, Germany, on 26th March 2006. During this largest ever aircraft evacuation trial 853 passengers and 20 crew members left the aircraft within 78 seconds 12 seconds less than required, validating 853 as the maximum passenger seating capacity, for the A380-800. Although not required for certification, but part of Airbus' commitment to smooth entry into service, Airbus undertook a series of four Early Long Flights in September 2006 where over 2000 Airbus employees took part to assess the cabin environment and systems in flight. These followed a 15 hour Virtual Long Flight, that took place in May 2006 in Hamburg, where 474 Airbus employees tested cabin systems in simulated long haul conditions. (7)
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8. Federal Aviation Administration (FAA)
8.1. Background
Federal Aviation Administration (FAA) is an agency of the U.S. Department of Transportation with the authority to regulate and oversee all aspects of civil aviation. The establishment of the Federal Aviation Act of 1958, a group under the name "Federal Aviation Agency", and adopted its current name in 1967 when it became part of the United States Department of Transportation. There are numerous regulations from the FAA, which was established to address the issues of safety and reliability of each aircraft. Designer who want to create new aircraft or to adapt an old aircraft to be new in market, must be concerned about Federal Aviation Administration regulation, because if the aircraft does not meet the organization, then it must be that this aircraft has not received a certificate from the Federal Aviation Administration, and as a result, the aircraft with the lack of qualified work. Designers and engineers should be aware of regulation and standards in the selection of systems, as mentioned in FAA and the bottom line of security and reliability issue. The following pages summarize all the important ones that affect: 1. 2. 3. 4. 5. Landing gear Structural design Engine Hydraulic system Special conditions (Special design standards of an unusual aircraft like A380)
The FAA is responsible for the safety of civil aviation. Its main roles include: 1. Regulating civil aviation to promote safety. 2. Encouraging and developing civil aeronautics, including new aviation technology. 3. Developing and operating a system of air traffic control and navigation for both civil and military aircraft. 4. Researching and developing the national airspace system and civil aeronautics. 5. Developing and carrying out programs to control aircraft noise and other environmental effects of civil aviation. 6. Regulating US commercial transportation.
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9. Federal Aviation Administration (FAR 25: Landing gear)
9.1. FAR section 25.721 - General
The system of the main landing gear must be designed in a way if the landing gear fail or collapse during takeoff and landing according to the load that applied to the landing gear is more than the maximum load of landing gear can hold, the failure mode is not likely to cause the spillage of enough fuel from any part of the fuel system to delegate a fire hazard. The aircraft that has passenger more than ten seats excluding pilot seats must be designed with the condition that if the aircraft is in under control, the aircraft can be landed on a paved runway without a structural component failure. (8)
9.2. FAR section 25.723 - Shock absorption tests
The energy absorption tests at limit design conditions must include at least the design landing weight or the design takeoff weight. Moreover, the test attitude of the landing gear unit and the application of appropriate drag loads during the test must simulate the airplane landing conditions. The landing gear may not fail in a test, demonstrating its reserve energy absorption capacity, simulating a descent velocity at design landing weight. (9)
9.3. FAR section 25.731 - Wheels
The main and nose wheel must be approved and the maximum static load rating of each wheel may not be less than the corresponding static ground reaction with the design maximum weight and critical center of gravity. The maximum limit load rating of each wheel must equal or exceed the maximum radial limit load determined under the applicable ground load requirements of this part. The overpressure burst must be prevented from excessive pressurization of the wheel and tire. (10)
9.4. FAR section 25.733 - Tires
The tires that are chosen must fit appropriate to the wheel with a speed rating approved by the Administrator which is not overdo under critical conditions and with a load rating must not exceed under the loads on the main wheel tire, the loads corresponding to the ground reactions. The tires that are installed to the retractable landing gear must have the clearance to surrounding structure and systems which is enough to prevent unpredictable damage between the tire and other part of aircraft structure. For the airplane that has the maximum takeoff weight more than 75,000 pounds, the tires mounted on braked wheels must be inflated with dry nitrogen or other gases. (11)
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9.5. FAR section 25.735 - Brakes and braking systems
The brake system must have capability to bring the airplane to the rest with a braked roll stopping distance of not more than two times when any single source of hydraulic or other brake energy supply is lost. The parking brake control of airplane must be selected on for preventing rolling on a dry of the airplane. Moreover, this control must have capability enough to prevent inadvertent operation. For kinetic energy capacity, when design landing stop, it must use the dynamometer for testing that the wheel, brake and tire have capability of absorbing the kinetic energy in the accepted level or not. The mean deceleration must not be less than 10 fps². (12)
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9.6. FAR section 25.737 - Skis
The 14 CFR parts 25 section 737 states "Each ski must be approved. The maximum limit load rating of each ski must equal or exceed the maximum limit load determined under the applicable ground load requirements of this part".
9.7. FAR section 25.487 - Rebounding landing condition
In this section, it’s divided into two main parts. 1. Landing gear structure must qualify the aircraft loads that will occur during rebound. 2. If the landing gear is fully extended without contact with the runway, a load factor of 20.0 must operate on the unapplied weights in the direction of motion of the unapplied weights. (13)
9.8. FAR section 25.1515 - Landing gear speeds
The operating speed, VLO, must not more than the safety level in both to extend and to retract the landing gear. In case of extension speed, the speed VLE must definitely not exceed the speed when the aircraft fly with fully extended landing gear. (14)
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9.9. FAR section 23.729 - Landing gear extension and retraction system
For an airplane with retractable landing gear must be designed for maximum flight load factors with the gear retracted and must be designed for the combination of friction, inertia, brake torque, and air loads, occurring during retraction at any airspeed up to 1.6 VS1 with flaps retracted. For an emergency case, if aircraft cannot be able extended manually, there must be able to extend the landing gear in the normal landing gear operation system or in a power source that prevent the operation of the normal landing gear operation system. In every aircrafts, the landing gear warning devices need to be installed. For landing approach, if the landing gear is not fully extended and locked, the warning system must be designed for this situation. Another circumstance that must be concerned is that when the wing flaps are extended over the maximum flap position, the warning system for this device may use any part of the system including aural warning device. (15)
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10.Federal Aviation Administration (FAR 25: Structural and Design)
10.1. FAR section 25.303 - Factor of safety
A factor of safety of 1.5 must be applied to the limit load which are concerned external loads on the structure and when a loading condition is dictated in terms of ultimate loads, a factor of safety do not need to be applied. (16)
10.2.
FAR section 25.307 - Proof of structure
The structure must be in an acceptable level in the issues of strength and deformation requirement for each critical loading condition. The ultimate load tests need to be done when the limit load tests are not sufficient. Before choosing material, the administrator need to test the material correction factors that appropriate to the structure or not. (17)
10.3.
FAR section 25.341 – Gust and turbulence loads
In the issue of discrete gust design criteria, the vertical and lateral gusts need to be symmetrical in level flight. Loads on each part of the structure must be determined by dynamic analysis. The analysis must take into account unsteady aerodynamic characteristics and all significant structural degrees of freedom including rigid body motions.
10.4.
FAR section 25.523 - Design weights and center of gravity positions
For design weights, the water load requirements must be met at each operating weight up to the design landing weight except, the design water takeoff weight must be used. For center of gravity positions, the critical centers of gravity within the limits for which certification is requested must be considered to reach maximum design loads for each part of the seaplane structure. (18)
10.5.
FAR section 25.603 - Materials
The suitable materials that will use for many parts of structure must pass the basis of experience or tests and these materials need to be approved by the industry or military specifications or Technical Standard Orders to ensure that these materials have the strength and other properties enough to use. Moreover, if all of above are satisfied, the environmental issues are needed to be accounted for example temperature, and humidity. (19)
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10.6.
FAR section 25.631 - Bird strike damage
The main detail for this section is that "The empennage structure must be designed to assure capability of continued safe flight and landing of the airplane after impact with an 8-pound bird when the velocity of the airplane (relative to the bird along the airplane's flight path) is equal to VC at sea level, selected under §25.335(a). Compliance with this section by provision of redundant structure and protected location of control system elements or protective devices such as splitter plates or energy absorbing material is acceptable. Where compliance is shown by analysis, tests, or both, use of data on airplanes having similar structural design is acceptable."
10.7.
FAR section 25.681 - Limit load static tests
The limit load requirement for this section must test the direction of the test loads produces the most severe loading in the control system including fitting, pulley and bracket used in attaching to the main structure. (20)
10.8.
FAR section 25.843 - Tests for pressurized cabins
The main idea from this section is that "Flight tests, to show the performance of the pressure supply, pressure and flow regulators, indicators, and warning signals, in steady and stepped climbs and descents at rates corresponding to the maximum attainable within the operating limitations of the airplane, up to the maximum altitude for which certification is requested. " In addition, the tests of the pressurization system to show proper function under each possible condition of pressure, temperature, and moisture, up to maximum altitude for which certification is requested.
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11.Powerplant
11.1. FAR section 25.903 - Engines
The powerplants must be installed separate to each other for preventing failure of any engine or any system that can affect the engine. The airplane that uses the turbine engine must have the precaution for minimizing the dangerous in case of an engine rotor failure. Moreover, the engine control devices, systems, and instrumentation must be designed to provide sufficient assurance. The turbine engine powered airplanes must have capability to restart the engine by using a power source independent of the engine-driven electrical power generating system to allow in-flight engine ignition. (21)
11.2.
FAR section 25.939 - Turbine engine operating characteristics
Turbine engine operating characteristics must be examined to classify that no adverse stall, surge, or flameout to a risk degree during normal and emergency operation within the range of operating limitations of the airplane. (22)
11.3.
FAR section 25.963 - Fuel tanks: general
The materials that use to build the fuel tank must be able to resist without any failure modes. There are two main types of fuel tank which are flexible fuel tank and integral fuel tanks. Each of fuel tank must be approved and have the particular application. For the fuel tanks which near the fuselage must have the capability to resist rupture and retain fuel under the inertia forces for emergency landing. For the fuel tank access covers, all covers must have minimize penetration and deformation bye tire fragments, low energy engine debris and all cover must have the qualification to resist fire. (23)
11.4.
FAR section 25.1125 - Exhaust heat exchangers
Each exhaust heat exchanger must resist each vibration, inertia, and other load. Moreover it must be able to operate at high temperatures and resistant to corrosion from exhaust gases. The cooling provisions must have in each of exchanger. In case of exhaust heat exchanger is used for heating ventilating air, a secondary heat exchanger must be provide between the primary exhaust gas heat exchanger and the ventilating air system. (24)
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11.5.
FAR section 25.1141 - Power plant controls: general
Each control must be located on the place that cannot operate by people who entering or leaving in that area normally in cockpit. Each flexible must have the particular application and have sufficient strength and rigidity to withstand operating loads without any failure modes. (25)
11.6.
FAR section 25.1203 - Fire detector system
The numbers and locations detection of fire must be classified and each fire detector system must be constructed and this system must also withstand the vibration, inertial, and other loads. Any oil, water, and other fluids might not cause the effect to fire and overheat detector. Crew must have capability and allowable to check each fire or overheat detector during in flight. Fire or overheat detector must not go through other fire zone unless the zones are relevant to prevent by this detector. (26)
11.7.
FAR section 33.76 - Bird ingestion
The FAA regulation 14 CFR part 33 section 76 states "All ingestion tests shall be conducted with the engine stabilized at no less than 100-percent takeoff power or thrust, for test day ambient conditions prior to the ingestion. In addition, the demonstration of compliance must account for engine operation at sea level takeoff conditions on the hottest day that a minimum engine can achieve maximum rated takeoff thrust or power". Additionally, the test by using the large bird ingestion needs to be done by using a weight of bird from the table below. The aim of this test is to explore the most critical exposed location on the first stage of rotor blades.
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11.8.
FAR section 33.83 - Vibration test
The vibration qualification must be required by establishing the vibration surveys of each engine and this qualification must be in acceptable level throughout the flight envelope. These surveys also accumulate the ranges of power, thrust, and rotational speeds for each rotor system. The effects on vibration characteristics of excitation forces caused by fault conditions (such as, but not limited to, out-of balance, local blockage or enlargement of stator vane passages, fuel nozzle blockage, incorrectly schedule compressor variables, etc.) shall be evaluated by test or analysis, or by reference to previous experience and shall be shown not to create a hazardous condition. In addition, The FAA regulation 14 CFR part 33 section 83 says "Compliance with this section shall be substantiated for each specific installation configuration that can affect the vibration characteristics of the engine. If these vibration effects cannot be fully investigated during engine certification, the methods by which they can be evaluated and methods by which compliance can be shown shall be substantiated and defined in the installation instructions required by §33.5. "
11.9.
FAR section 33.88 - Engine over temperature test
The turbine must be in serviceable limits by following this method which is each engine must run for 5 minutes at maximum permissible rpm with the gas temperature at least 75°F or 42°C higher than the maximum rating's steady-state operating limit. (27)
11.10.
FAR section 33.94 - Blade containment and rotor unbalance tests
The engine need to be demonstrated in the test that this engine has enough capability to carry damage without any failure modes and catching fire when the test is being done at least for 15 seconds. According to the FAA regulation 14 CFR part 33 section 94 claims that failure of the most critical compressor or fan blade while operating at maximum permissible rpm. The blade failure must occur at the outermost retention groove or, for integrally-bladed rotor discs, at least 80 percent of the blade must fail.
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12.Hydraulic system
12.1. FAR section 25.1435 - Hydraulic System
Element Proof Ultimate (xDOP) (xDOP) 1.5 3.0
12.1.1. Element design
1. Tubes and fittings 2. Pressure vessels containing gas: High pressure (e.g., accumulators) 3.0 4.0 Low pressure (e.g., reservoirs) 2.0 3.0 3. Hoses 2.0 4.0 4. All other elements 1.5 2.0 Proof and Ultimate pressures in terms of the design operating pressure (DOP) Each element of a hydraulic system must stand and be resisted to:
1. The pressure without permanent deformation and the ultimate pressure without rupture. 2. Elements in a hydraulic system should withstand without deformation, the design operating pressure in combination with limit structural loads that may be imposed. 3. Elements must withstand without rupture when using a factor of 1.5 by multiplying (DOP) in combination with ultimate structural load. 4. Elements must withstand the fatigue effects of cyclic pressures. 12.1.2. System design The main issues that each hydraulic system must meet: 1. 2. 3. 4. Located at a flight crew station to indicate appropriate system parameters System pressures are within the design capabilities of each element Degraded the release of harmful of hydraulic fluid during flight Designed to use a suitable hydraulic fluid specified by the airplane manufacturer
12.1.3. Tests Each element related to a hydraulic system must be pass the tests before are set to service. Failure of an element at testing stage can occur, so elements error must be collected and retested. In the test, the significant issues that each element must be tested are ï‚· ï‚· ï‚· Performance Fatigue Endurance of airplane ground and during flight operations (28)
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12.2.
A380 Hydraulic System
Aircraft manufacturers are one of the most important industries, focusing mainly on the structure of the aircraft's weight. Every extra pound consumes more fuel and that means it will increase the cost risk. Airbus previous models were using a hydraulic system that would produce 3000 lbs / square inch, but Airbus invited a new system to support it late test model A380 which will make it completely different. Airbus A380 can carry up to 800 passengers on single class with an estimated travel distance of up to 8000 miles on full fuel tanks that means Airbus engineers need to think of a new compatible hydraulics system technology to be fitted on A380 to. Prior to Airbus decision, Engineer begun to communicate with hydraulic systems industry, where they initiated several hydraulic discussion aims about both advantages and disadvantages of the current systems used. In conclusion of discussion, a hydraulic system of 5000 lb / square inch of water was developed and to be used in A380. (29) Hypertension from 3000 to 5000 lbs / square inch benefited A380 program because it allows the same transmitted energy required to be delivered with a smaller pipes and hydraulic components, where it reduces the weight of the aircraft at about one metric ton. An A380 hydraulic system has been used by defense force on their high-pressure systems for years, and which has evolved to 5000 lbs / square inch and stood well to test rehabilitation. Experience has shown with the existing hydraulic fluids and components that the fluid does not degrade under greater pressure. Airbus engineers have chosen Eaton hydraulic system to provide 5000 lbs / square inch for hydraulic power generation in A380. There are several important issues that should be concerned carefully in the 5000 lbs / square inch, like: ï‚· Stress factors ï‚· Pulse pressure ï‚· Efficiency ï‚· Deflection pressure ï‚· Balances the pressure ï‚· Materials selection Eaton hydraulic system is made of: ï‚· ï‚· ï‚· Eight Vickers PV3 -300-31 hydraulic engine-driven pumps (EDPs) Four AC motor pumps (The largest ever designed to date for an aircraft) Electronic control and protection systems
(30)
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13.Special Conditions (FAR 25: Structural and Design)
13.1. Special Conditions: Airbus Model A380-800 Airplane, Crashworthiness
The size and configuration of Airbus A380 are the main subjects that make this special condition occur. According the FAA regulation 14 CFR part 25 sections 561 stated that the design load conditions must cover the emergency landings for the local structures in the passenger compartment. The structure of airplane must show the reasonable capability of the airframe in crash landings. However, the FAA hasn't got much enough information to confirm that the structure of Airbus A380 has capability to qualify the safety requirement. Hence, the FAA decides to offer the special condition which emphasizes to test and analyze the structure to satisfy a level of crash survivability equivalent to conventional large airplanes. The vertical loading of the fuselage is the only issue that will address in this special condition This special condition also has some doubts especially in case of safety and reliability issues so the FAA decides to establish a referenced point to compare the structure capability of A380 with the structure of current large aircraft. This reference point is namely as "Limit of Reasonable Survivability". The vertical descent rate is defined in this reference point by exceeding of physiological limits of the occupants. (31) FAA gives some recommendation about this special condition "Accommodating the changes requested by ALPA would be beyond the scope of this rulemaking. The purpose of the special condition is to assure that the large size and full length double deck configuration of the A380 design do not degrade the survivability characteristics of the A380 fuselage shell compared to designs for conventional large transport category airplanes. The purpose is not to create a higher safety standard for the A380."
13.2.
Special Conditions: Airbus Model A380-800 Airplane, Airplane Jacking Loads
This special condition is the supplementary condition for the FAA regulation 14 CFR part 25 sections 519. Due to Airbus A380 has a multi-leg landing gear configuration which is two wing mounted gear, nose gear, and two body mounted gear but this arrangement is not match to the FAA regulation which said that an arrangement of landing gear consisting of three point suspension system. As a consequence, this may not affect to share the load between landing gear if follow the FAA regulation but the Airbus A380 has five point suspension systems so the special condition needs to be established. In this case, calculation of loading sharing between landing gear units has to be done. A rotational analysis of the jacking condition for the main and body landing gear is permitted in this special condition including the case of bogie gears where on leg of a bogie is jacked and other leg is supported on a tripod. (32)
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13.3. Special Conditions: Airbus Model A380-800 Airplane, Transient Engine Failure Loads
With a very large high bypass ratio engines of A380 model which is 110 inch diameter bypass fans result in the larger size of the engine which normally be the cause of higher inertia of the rotating components. This was not envisioned with Sec. 25.361 (pertaining to loads imposed by engine seizure) which was adopted in 1965; for that reason, there are two other sections that need to be referred: Section 25.361(b) (1) requires that for turbine engine installations, the engine mounts and the supporting structures must be designed to endure a “limit engine torque load imposed by sudden engine stoppage due to malfunction or structural failure." Limit loads are expected to occur about once in the lifetime of any airplane. Section 25.305 requires that supporting structures be able to support limit loads without detrimental permanent deformation, meaning that the supporting structures From the adoption of Sec. 25.361(b) (1), the size, configuration, and failure modes of jet engines have altered considerably. Currently, many engines are much larger and designed with large bypass fans. In the event of a structural failure, these engines are capable of producing much higher transient loads on the engine mounts and supporting structures. As a consequence, the modern high bypass engines are exposed to the certain rare-but-severe engine seizure events. Owing to the service history, it shows that these events occur far less frequently than limit load events. Even though it is essential for the airplane to be able to support such rare loads safely without failure, and it is impossible to expect that no permanent deformation will occur. From the above situation, a design standard for today's large engines has been proposed by Aviation Rulemaking Advisory Committee (ARAC). For the commonly-occurring deceleration events, the engine mounts and structures are required to support maximum torques without detrimental permanent deformation as the proposed standard. For the rare-but-severe engine seizure events (i.e., loss of any fan, compressor, or turbine blade), the engine mounts and structures to support maximum torques without failure are needed for proposed standard, but allows for some deformation in the structure. In conclusion, the FAA considers that modern large engines, including those on the Model A380, are novel and unusual compared to those envisioned when Sec. 25.361(b) (1) was applied and thus warrant special conditions. Besides the special conditions also includes design criteria, as recommended by the ARAC. For the ARAC proposal, it needed to be revised in the wording of Sec. 25.361(b), including Sec. 25.361(b)(1) and (b)(2), removing the language pertaining to structural failures and moving it to a separate requirement which discusses the reduced factors of safety that apply to these failures. The revised wording of Sec. 25.361(b) would also include non-substantive changes recommended by ARAC to clarify the existing requirement. Moreover, the FAA is employing this ARAC text in these special conditions, because it clarifies the supplementary conditions for engine torque. (33)
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13.4. Special Conditions: Airbus Model A380-800 Airplane, Reinforced Flight deck Bulkhead
The unusual design features bring to Airbus A380 has so many special conditions. In this special conditions will generate the flight deck bulkhead of A380. According to the FAA regulation 14 CFR part 25 section 795 states that the installation of flight deck door must be designed to oppose the unauthorized persons by any efforts. This regulation has a limit only the flight deck door but for the Airbus A380, the flight deck bulkhead needs to be classified. The FAA is now making the amendment of this regulation section, whereas, the special condition is established. This special condition requires that the door of the flight deck bulkhead use the same standard and meet the requirement in 14 CFR part 25 sections 795. (34)
13.5.
Special Conditions: Airbus Model A380-800 Airplane; Fire Protection
This special condition is the additional information of 14 CFR part 25 sections 857. The full-length double deck passenger cabin and electrical equipment bays are the direct effects to this special condition. The current regulation of FAA 14 CFR part 25 sections 857 said that cargo compartments have a means to separate the dangerous of smoke to the occupied area of the airplane. However, this regulation does not cover the dangerous of smoke from one deck to another deck or between two decks via a connection stairway. Moreover, the current FAA regulation does not state about the detection of smoke in an electrical equipment bay. Usually, the electrical equipment bay located under the flight deck but for Airbus A380, it might bring to the risk of smoke which may affect to passengers and crew. (35) The FAA establishes this special condition for covering the lack of issues.
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14.Special Conditions (FAR 25: Landing Gear)
14.1. Special Conditions: Airbus Model A380-800 Airplane; Loading Conditions for Multi-Leg Landing Gear
This special condition is quite similar to the airplane jacking loads special condition that discuss in the structural and design section. For this special condition will focus mainly on the landing with load condition suitable for multi-leg landing gear of A380. (36) The ARAC working group proposes this special condition gathering various landing gear configurations. According to the ARAC working group, this notice can classified into two groups of special conditions. (Group A) addresses landing conditions as the following: A.1. Landing load conditions and assumptions A.2. Symmetric landing load conditions A.3. One-gear landing conditions A.4. Side load conditions (Group B) addresses other conditions and tests including Ground Handling Conditions as the following: B.1. Ground handling conditions B.2. Taxi, takeoff and landing roll B.3. Braked roll conditions B.4. Nose-wheel yaw and steering B.5. Pivoting B.6. Reversed braking B.7. Ground load: unsymmetrical loads on multiple-wheel units B.8. Shock absorption tests
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14.2.
Special Conditions: Airbus Model A380-800 Airplane, Ground Turning Loads
This special condition is the supplementary information of the FAA regulation 14 CFR part 25 sections 495. According to the FAA regulation 14 CFR part 25 section 495 stated that the current or conventional aircrafts which are the lateral loads experienced by the bigger aircrafts during ground turns are less than the smaller aircrafts do. Meanwhile, the Airbus A380 is heavier than others more than approximately 30% so Airbus A380 cannot use the 0.5 g design turning load factor which is claimed in the FAA regulation 14 CFR part 25 sections 495. Hence, the new design turning load factor which is suitable to the size of A380 is 0.45. (37)
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15.Verification and Validation Process (V & V)
Verification and Validation is a model that helps system designers and test engineers in confirming that a product being built correctly throughout the development process to improve software product quality. (38)
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Verification and Validation process confirm that certain rules are followed correctly in the process of software product development, also confirms that a product is developed to fulfill the required specifications. V&V reduces any associated project risk to certain level by helping in early detection and correction of errors, which are usually built without a notice during development process. (38)
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15.1.
Verification
Design verification aims to provide evidence that the design meets the requirements, this line of evidence presented through the analysis of the project, and a major contribution to make a decision on the selection of the design decisions and to begin the next phase of development, or in other words is to know if we building the right product or not. (38) Methods and techniques used in the verification process must be designed carefully. There are three main methods used in verification: inspection, walkthroughs and buddy checks. Inspection: Inspection includes a group of 3-6 people, led by the leader, who formally review the documents and work product in various stages of the life cycle of product development. Work product and related documents submitted to the inspection team, which leads to different interpretations of the presentation. Errors discovered during the inspection are sent to the next level with care. Walkthroughs: Can be seen wandering the same examination without formal training (i.e., view or document). During the passage of the main meeting / Authors submit articles to all the participants in order to make them familiar with it. Even walkthroughs can help identify potential errors, but it’s mainly used for a knowledge exchange and communications objectives. Buddy Checks: This is the easiest type of review activities, which were used to identify errors in the product during verification. Buddy checks sets one person to go through the documents prepared by someone else in order to ensure that the person committed no error (s), i.e. errors discovery that author cannot find before. In addition, there are two main ways where the basic techniques are used widely in a large company. Main methods for testing are dynamic and static testing. (38) Dynamic testing: In principle, is to choose a number of tests cases where each test case consists of test data. The input test cases are used to determine the test results yield. Dynamic test can be divided into three categories - functional testing, structural testing and random testing. Functional testing: Involves identifying and testing all the functions of the system, as defined within the requirements. This type of testing is an example of black box testing because it doesn’t require you to know about the implementation of this system. (39) Structural testing: It’s a complete knowledge on the implementation of the system and an example of white box testing. It uses the information from the internal structure of test development to test individual components. Functional and structural testing chooses test cases that investigate a particular characteristic of the system.
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Random testing: Choosing freely test cases from a range of test cases for all possible tests. It determines by the use of random inputs that can detect errors which are detected by other means of testing methodology. Exhaustive testing, where the input test cases consists of every possible set of input values, is a form of random testing. Although exhaustive testing is comprehensive in each stage of the life cycle results in a full system scan, it is really impossible to meet. Stating testing: Not associated with the system or component operation where some of these methods of manually, and other automated. Static testing can be divided into two techniques categories - techniques that analyze consistency and techniques that measure some program property. Consistency techniques: Used to ensure that the properties of a program such as the correct syntax, the correct parameter matching between the procedures printed correctly, and correct translation of the requirements and specifications. Measurement techniques: Measure properties such as the errors tendency, clarity, and wellorganized. (39)
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15.2.
Validation
Validation is to ensure that the requirements of a product are correct and complete enough to ensure the safety and customer satisfaction within the limits of the program. All types of testing methods are carried in the verification process. Test plan, test suits and test cases are developed that are used during different stages of the verification process. There are four phases involved in validation processes: (40) Code Validation/Testing: Developers as well as testers do the code validation. Unit Code Validation or Unit Testing is a type of testing, which the developers conduct in order to find out any bug in the code unit or module developed by them. Integration Validation/Testing: Is carried out in order to find out if different (two or more) units/modules co-ordinate properly. This test helps in finding out if there is any defect in the interface between different modules. Functional Validation/Testing: Is carried out in order to find if the system meets the functional requirements. In this type of testing, the system is validated for its functional behavior. Functional testing does not deal with internal coding of the project, instead, it checks if the system behaves as per the expectations. User Acceptance Testing or System Validation: Developed product is handed over to the user/paid testers in order to test it in real time scenario. The product is validated to find out if it works according to the system specifications and satisfies all the user requirements. As the user/paid testers use the software, it may happen that bugs that are yet undiscovered, come up, which are communicated to the developers to be fixed. This helps in improvement of the final product. (38)
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As the figure above shows that verification and validation process (V & V Process) comes after development process. Verification and Validation are part of the long certification process for any system. There are several reasons why a product needs certification. The legal reasons play as an important role in this certification. (41) "Even though certification does not occur until the end of a system development cycle, the planning starts from the very beginning. Because certification is a complicated process between the developer and the regulatory agency, the certification liaison between the parties must be established early on in the process. Next, the developer should submit a verification plan for approval by the regulatory agency. After the submission, discussion takes place between the developer and regulatory agency to resolve areas of misunderstanding and disagreement. Changes to the methods used have to be approved by the regulatory body to insure that certification will not be affected. Throughout the entire development life cycle of the product, documentation must be continually submitted to show that the certification plan is satisfied. The regulating authority will also hold a series of reviews to discuss the submitted material. At the end, if the terms of the certification plan have been satisfied, then a certificate or license is issued" stated by Eushiuan Tran, verification/validation/certification article. Airbus Company uses this process to satisfy the requirement. Obviously, A380 has unusual design features so this leads Airbus to show that this aircraft is ready to carry 500 passengers. There are several topics that Airbus is concerned with the A380, therefore this project will cover in four main areas: Landing gear, brake and steering system, Hydraulic system, Structural and Design, and Power plant.
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16.Landing Gear, Brake, and Steering System
Landing gear, brake, and steering system is an important primary topic that must be concerned due to the fact that Airbus A380 is the world largest aircraft which consists of thousand components, where majority of components are used had been enhanced with latest technology that the manufacturer of each component must significantly investigate and explore. The A380 landing gear is the world’s largest landing gear that has ever been build to an aircraft. This landing gear consists of 6 main sections which are the following: Gears ï‚· Nose landing gear ï‚· Body landing gear x2 ï‚· Wing landing gear x2
(2 wheels) (Bogie Type, 6 wheels - 4 braked) (Bogie Type, 4 wheels - 4 braked)
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Extension/Retraction System
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Braking Control System
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Steering Control System
ï‚· ï‚·
Nose Wheel Steering Body Wheel Steering
Wheels, Tires and Brakes (16 Braked wheels)
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Monitoring Systems
ï‚· ï‚· ï‚·
Tire Pressure Indication System Brake Temperature Monitoring System Oleo Pressure Monitoring System (OPMS)
The design of this landing gear must satisfy the basic requirements, for that reason there are two minimum requirements manufacturers must comply with ICAO code E and FAA group V airports: 1. 45m runways and 23m taxiways 2. Possible U-turn on 60m wide runway
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16.1.
Equipment Tests
16.1.1. Nose Landing Gear Messier-Dowty was selected to design, manufacture, test, and support the nose landing gear for the ultra-large Airbus A380 Aircraft in 2001. Messier-Dowty has a long experience on all existing Airbus Aircrafts. In the forward retracting nose landing gear, it introduces many modern technologies such as the use of an HVOF (High Velocity Oxygen Fuel) surface treatment process to replace the use Chromium plating, which is more environmentally friendly, and a 350-bar hydraulic system which never been used before on large commercial aircraft. (42) Main components of the A380 nose landing gear are: Main fitting and sliding tube, both were produced in Montreal, Canada and in Bidos, France, respectively. Nose landing gear main testing took place in Gloucester, UK and at the CEAT center in Toulouse, France. Eight of A380 nose landing gears were manufacturer in 2004.
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In January, 2004 - The A380 nose landing gear were delivered to Airbus UK. Standing at 4.8 meters tall when fully extended, the gear were fitted to the Airbus system test rig located at Filton, England for validating aircraft system performance. During nose landing gear test, it showed that nose landing gear is more environmentally friendly due to the use of new materials. The nose landing gear is capable of absorbing and transmitting the towing forces which essential to overcome the inertia of a fully landed aircraft. Additionally, the hydraulic system generates more power while enhancing its performance. (43)
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Airbus A380 Nose Wheel Steering (NWS) assembly. It can move more and less than 60 degree in Towing angle. For hydraulic steering angle, it can move more and less than 70 degree, and can move more and less 75 degree in mechanical stop angle.
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16.1.2. Main Landing Gear Airbus A380 main landing gear was developed by Goodrich Corporation, one of the world's leading suppliers of landing systems for commercial and military aircraft. Goodrich Corporation provides the body and wing landing gear for Airbus A380. In April, 2005 - Goodrich Corporation established the world's largest landing gear test facility in Oakville, Ontario, Canada. A super rig test was tested in this facility. Moreover, the structure of the A380 body and wing landing gear was tested in this facility which covered strength and fatigue testing issues. The test rig rests in a cavity 55 meters long and stands approximately 8 meters high. Additionally, the facility also provides rigs for endurance testing. (44) After suspending the 12,000 pound body gear 12 feet high above concrete, LMS engineering performed an Experimental Modal Analysis (EMA) modal test to A380 body landing gear. This test allowed Goodrich to validate FE models of this rather complex mechanical assembly. Mr. Alvin Fong, Manager of Landing Gear Performance at Goodrich's Oakville landing gear facility commented on the test "The six-wheel landing gear system weighs approximately 12,000 pounds, and its size exceeds 25 feet when fully extended. In landing gear system development, it is our task to meet the required modal stability and structural performance to ensure that the gear will safely react to all loads and circumstances it will encounter throughout its service life."
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The test set-up required LMS to fabricate two solid stands with 5,000 pounds for each fill. LMS decided to pre-load the body landing gear unit with static forces for avoiding free-play in landing gear joint. LMS engineering decided to install two electro-dynamic shakers which can generate 1,000 Newton peak forces in order to provide sufficient energy while performing modal tests on a specimen of this size and weight. During the first time test, the modal test showed that the test rig exhibits around 8 Hz. After this test, LMS engineering added a number of rig measurement points to the modal test geometry of the landing gear unit. (45) To verify the quality of the modal test set-up, Paul Weal, Business Development Manager of LMS Engineering Services said “When evaluating structural FRF coherence and reciprocity, the two burst-random shaker inputs created only limited nonlinear landing gear behavior in static stroke and extended positions, at specified force levels between 5 and 15 Newton."
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The major mode shapes extracted from the test data were used to verify finite-element landing gear models at Goodrich and supported structural investigations at Airbus.
Additionally, Paul Weal said "However, when increasing force levels firmly using stepped-sine excitation - 200 up to 1,000 Newton - we identified stronger non-linear behavior, mainly as a result of slight backlash that was present in the huge landing gear joint connections. When testing at highest force levels, the resulting bending and torsion modes became truly visible, as we witnessed displacements of about 1 inch. With the help of driving point FRF functions, we quantified the evolution of growing non-linearity that is exhibited in response to increasing force levels."
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The actual model analysis test campaign started after the selection of the landing gear modes. The most significant modes retrieved for the landing gear static stroke configuration were foreaft, lateral and torsional resonance below 15 Hz. For extended Stroke, the identified fore-aft, lateral and torsional modes were lower than static stroke modes. In general, the measured modal frequencies turned out to be lower than then- predicted counterparts. The project confirmed the model characteristics of the starboard body landing gear system. The major mode shapes extracted from the test data were used to verify FE landing gear models at Goodrich and supported structural investigations at Airbus.
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After suspending the 12,000 pound body gear 12 feet high above concrete, they applied burst-random and steppedsine excitation up to 1,000 Newton force levels.
Test also explored potential dynamic influences of the Super Rig on the mode shapes of the actual landing gear. The model analysis showed strong coupling of the landing gear and test rig dynamics, particularly in the 5 and 8 Hz regions.
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To be able to provide sufficient energy while performing modal tests on a specimen of this size and weight, LMS engineering consultants installed multiple shakers.
In July, 2005 - Airbus Company announced that the test of the A380 wing and body main landing gear is in expected levels. The test was designed to go way beyond the limit of normal operations and was the equivalent of the structural static airframe tests to destruction. (46)
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16.1.3. Landing Gear Extension and Retraction System In April 2002, Smith Aerospace started a contract with Airbus to supply A380 landing gear extension and retraction system. This contract is the fourth contract on the new 555 seat aircraft. The previous contracts are wing flaps and slats, landing gear actuation, and fabricated assemblies for the wing structure. (47) Highly Accelerated Life Testing (HALT) was used to evaluate the performance of Airbus A380 landing gear extension and retraction (LGERS). This is the first time for HALT to use for hydro mechanical systems. Moreover, it took advantage of new materials to reduce the system's weight. (47)
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Highly accelerated lift testing (HALT) of the pitch trimmer actuators – conducted to investigate the effects of high frequency dither on the seals.
The component of up locks, valve housings, actuators and pitch trimmers have been completely investigated at Cheltenham and Yakima, Washington, USA. In test rig, Smiths tested the electrical actuated gear and door up locks. Rob Neal, actuation systems engineering director said "the use of electrical actuators will save 200 kg (440 lb) by eliminating mechanical pull cords on the emergency release system."
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Three A380 electromechanical up locks: in varying states of build and reserved for environmental, vibration and endurance testing. All have yet to be fitted with their normal unlock actuators, and only the one on the right is fitted with its two electro-mechanical emergency unlock actuators.
Airbus A380 is the first large civil aircraft to use High Velocity Oxy Fuel (HVOF) for seal wear reduction consist of actuator piston rod coating. Technically, HVOF is a method of deposition of tungsten carbide materials, and is a replacement for what is regarded as the environmentally unfriendly method of chrome-plating. HVOF also produces an exceptionally smooth surface; a chrome-plated surface can have microscopic fissures which at 5000-psi could allow leaks to occur.
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16.1.4. Brake and Steering System Airbus Company has made 5 major equipment contracts with Messier-Bugatti. These contracts are as the following: ï‚· ï‚· ï‚· ï‚· ï‚· The forward and main steering systems Tire, brakes and landing gear monitoring system Electro-hydraulic pumps for flight controls The "Full Brake By Wire" type brake regulation system Distribution and filtration system equipment in the hydraulic circuits of the aircraft
16.1.4.1.
Braking Control System
Messier-Bugatti's decided to use two main circuits for controlling the braking system, one is the main circuits which are driven by dedicated software in the Integrated Modular Avionics (IMA) suit, and another alternative has an analog computer to control. Messier-Bugatti supplies the entire braking control system, including: 1. 2. 3. 4. 5. 6. IMA software Three RDAs with software EBCU backup computer Hydraulic equipment All sensors Decentralized hydraulic generators
In the mid of 2004, Messier-Bugatti completed the first series of tests on its new WABSIC (Wheel and Brake System Integrated Components). This is the first step on the road to qualification. This test was to validate the system's innovative concept under different braking conditions. Moreover, during the test, the observer investigated the comprising annular tachometer and tire pressure sensor with wireless transmission of data from the WABSIC. (48)
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16.1.4.2.
Steering System
There are two different steering systems: Nose wheels and Main landing gear wheels. The hydraulic circuits (at 5,000 psi) are the main circuit that uses to drive the two nose wheels. For the main landing gear, there is a single circuit which controlled by the braking RDCS
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Hydraulic unit for the A380 steering system on a test bench (Left), A380 brake manifolds, for the wing and fuselage landing gear (Right), Messier-Bugatti
16.1.4.3.
Tire, Brake and Landing Gear Monitoring Systems
The main requirement of improving volume and reliability for the A380 is by providing an evidence of real system innovations. These systems include the Tire Pressure Monitoring System (TPMS), Brake Temperature Monitoring System (BTMS) and Oleo Pressure Monitoring System (OPMS). In the TPMS, the mechanical and electric links connecting the pressure sensor incorporated into the rotating wheel and the fixed axle of the landing gear have been optimized significantly. The OPMS developed for the A380 is world first model. The monitoring data will send directly to the cockpit.
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Brake Temperature Monitoring System (Left), Tire Pressure Monitoring System (Right)
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17.Powerplant
The A380 can be fitted with two types of engines: 1. Rolls-Royce Trent 900 2. Engine Alliance GP7200
17.1.
Rolls-Royce Trent 900
The Rolls-Royce Trent 900 engines power the world's largest airliner, the Airbus A380. The Trent 900 was launched in February 2001. This type of engine is one of the most ambitious engineering programs in the company's civil aerospace history. The Trent 900 is the fourth member of the Trent family and holds pride of place as the largest jet engine ever produced by Rolls-Royce.
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Rolls Royce Trent 900 features: ï‚· Three-shaft architecture that makes the Trent 900 design simple, easy to transport and retain performance. This generation of Rolls-Royce's engine encompasses the latest technology which engineers research for several years. Moreover, Rolls-Royce also established demonstrator programs for providing more reliability and excellent operational capability and maintainability. The most environmentally friendly engine on A380 Due to the fact that our world becomes more concern about environment. Rolls-Royce reflects this campaign by the swept fan design which combined to whole engine design ensures that the Trent 900 meets stringent noise legislation. Reducing emissions is another topic that Rolls-Royce concerned. The Trent 900 by itself has tiled combustor in order to reduce emissions. A contra-rotating high-pressure spool, Trent 900 is the first engine in the Trent family to feature this outlook. There are several advantages in this design such as predictable maintenance system, reduced weight, and more efficient engine with lower fuel consumption. The engine has a baseline take-off thrust of 70,000lb and is certificated up to 80,000lb from the same bill of material. In testing, it has been run up to 93,000lb thrust. Performance of the engine is exceptional, meeting or exceeding all of the next generation targets it has been set. The Trent 900 is the first engine in the Trent family to feature a contra-rotating high-pressure shaft providing a more efficient engine with lower fuel consumption and reduced weight. In addition, QUICK, an advanced predictive maintenance system, has been introduced to reduce maintenance disruption and improve time on-wing. (49)
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17.1.1. Equipment Tests Trent 900 first run was in 2003 where Rolls-Royce decided to develop first seven engines in testing. Rolls-Royce had planned and tested many issues relevant to safety and reliability such as multiple bird strikes test, blade containment test, and water, hail and ice ingestion tests. All of these details will be in the qualification tests. In July 2003, latest nacelles were tested for fitting to the Trent 900. Xavier Bardey, Trent 900 nacelle program manager said “We mean all the mechanics and the electronics which make it possible for the reverser to work. This system, designed by our partner HispanoSuiza, had already been operated on a test rig. At Le Havre, we made sure that the system worked properly on an actual reverser before sending it to Rolls-Royce". These tests took for about two weeks. In late 2003, Rolls-Royce began to test the Trent 900 with bird strikes by simulation program in order to test durability against 2.5, 5.5 and 8 lbs bird impacts.
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Trent 900 Bird strike testing (Left), advanced 3D computer modelling of bird strike testing (Right)
The thrust reverser was tested on the Trent 900 which was used to assess the durability, the resistance of the structure, the vibration and temperature data, the operation of the reverser. After the test, engineers assured that the reverser met the performance objective relating to the air flow which is to be deflected forward on landing for the thrust to be reversed. (50) Rolls-Royce had run a ground-based altitude test which tested in April, 2004. These trials conducted at the U.S Air Force's Arnold Engineering Development Center (AEDC). The other tests are cyclic endurance trials at Derby, England with 150 hours test. The cyclic endurance evaluations ran the engine through 3,000 cycles to simulate airline operations. The type test put the engine through a variety of extreme operating conditions.
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In 2004, the Trent 900 was successfully gone through the blade containment test, which is one of the major safety tests in development of the engine. During testing, a fan blade was released at the root by detonating and explosive charge after the engine reached the maximum speed. (51) At the same time, the Trent 900 was successfully tested the performance testing in various extreme flight conditions including operation under severe icing conditions, altitudes in excess of 40,000 ft at speeds requirement by Airbus Company. Additionally, rain, hail, and ice ingestion has been tested.
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Rolls RoyceTrent 900 water ingestion test
Trent 900 received the certification from the European Aviation Safety Agency in October, 2004. Where required to operate at initially a maximum take-off thrust of 70 000 lbs, but it had cleared at an 80 000 lbs rating, allowing margin for future growth. It reached thrusts in excess of 90 000 lbs during test bed. A year after receiving EASA type certification, the first A380 flight powered by Trent 900 engines successfully took place. Four Trent 900s powered an A380 flight test aircraft began testing that included a cold weather campaign in Northern Canada and high altitude performance test in Colombia, together with hot weather testing in United Arab Emirates.
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Engineers conducting extreme heat conditions testing on the aircraft (Al Ain International Airport, UAE)
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17.1.2. Qualification Tests 17.1.2.1. Bird Ingestion (FAR section 33.76) Rolls-Royce responded to this requirement by demonstrating the capability of the Trent 900 by the impact of a 5.5 lb bird and the result has been completed successfully. The engine has not caused the condition of catch fire, release hazardous fragments through the engine casing or any other severe conditions. Additionally, Mr. Robert Nuttall, Rolls Royce marketing vice-president said "That was a new, high-energy impact test, and it was the first time anyone has done an engine test on that size of flocking bird"
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Rolls Royce Trent 900 brid strike test
17.1.2.2.
Rain and Hail Ingestion (FAR section 33.78)
Water, hail, ice ingestion were successfully completed before the Trent 900 achieved the type certification from EASA in 2004. The representative of Rolls-Royce Company stated with these tests that there was no surging, when experiencing severe and abnormal flight conditions.
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Rolls Royce Trent 900 water ingestion test
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17.1.2.3.
Vibration Test (FAR section 33.83)
The Rolls-Royce and Airbus Company had published that test has been completed in 2003. During the test, the engine satisfied the engineer by having low vibration and proving air and oil system. The Vibro-Meter had developed the Engine Monitoring Unit (EMU) for the Trent 900 engine. The EMU multi-monitor the engine vibration, observe the pressure, temperature and implements advanced algorithms for engine maintenance purposes. (52)
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Trent 900 Engine Monitoring Unit (EMU)
17.1.2.4.
Endurance Test (FAR section 33.87)
The 150 hour "red line" endurance test was completed in May 2004. Rolls-Royce tested the Trent 900 engine cycle-endurance where notch up around 3,000 cycles. This Trent 900 cycle tests included operations of the nacelle and thrust reverser. During the Trent 900 engine experienced the high temperature which was much higher than the other conventional aircraft meet, the engineers also could observe the thermal capability. 17.1.2.5. Engine Over Temperature Test (FAR section 33.88)
European Aviation Safety Agency DATA SHEET Number E.012 claims that "The Trent 900 is approved for a maximum exhaust gas over-temperature of 920 degrees Celsius for inadvertent use for periods of up to 20 seconds without requiring maintenance action".
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17.1.2.6.
Blade Containment Rotor Unbalance Tests (FAR section 33.94)
In July 2004, Rolls-Royce announced to the public that the Trent 900 engine had successfully completed a fan-blade containment test. During the test, the engine was accelerated to full speed before a fan blade was released at the root by an explosive charge. The blade and its debris were contained successfully and the engine performed a control shutdown. The blade-off test was also the first time that Rolls-Royce had performed this crucial test on a production engine fitted with highly swept wide chord fan blade. (51)
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Rolls Royce Trent 900 performing fan blade-off test
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17.2.
Engine Alliance GP7200
Engine Alliance GP7200 incorporates state of the art advanced technologies with a solid heritage of proven wide body products from the world's two leading aircraft engine manufacturers:
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GE Aircraft Engines Pratt & Whitney
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Engine Alliance GP7200 features: ï‚· ï‚· ï‚· ï‚· ï‚· Certificated at 81 500 lbs thrust to support 2006 A380 entry into service requirements. Built on GE90 and PW4000 mature reliability and leading edge technology Superior fuel efficiency World class emissions and low noise Thrust growth capability built in
The environmentally friendly GP7200 meets all ICAO gaseous emissions standards with substantial margin. According to EADS certification test data, the GP7200 powered A380 is the quietest A380. From Noise point of view, Engine Alliance GP7200 is a good neighbor where allowing the A380 to meet current stage 3 and proposed stage 4 noise level standards with margin.
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17.2.1. Equipment Tests The first GP7200 engine was completed in March, 2004. The GP7200 began test phase with sea level testing before beginning altitude testing at Arnold Engineering Development Center in Tennessee. (53)
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Engine Alliance and P&W GP7000 Project General Manager, speaks to the team that completed the final assembly of the first GP7200 engine.
The mechanical break-in cycle of the engine testing was complete in April, 2004. The GEP&W Engine Alliance's GP7200 engine has produced more than the 76 500 lbs of thrust required for entry into service on the Airbus A380 aircraft during its initial testing. The engine reached 80,000 pounds of at Pratt & Whitney's test facility in East Hartford, CT. Moreover, the mechanical stress is in the acceptable level. (54) At the same period of time, approximately one month of sea-level testing at P&W's facility, the engine ran 45 hours and achieved 86 500 lbs of thrust in the Airbus configuration (88000 lbs measured in cell conditions). The first engine to test (FETT) program also mapped the performance of the engine's advanced swept fan. After finishing test, Lloy Thompson, president of the engine Alliance stated that "This is one of the most successful FETTs I have seen". The next stage of this first engine is to undergo altitude testing.
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Engine Alliance GP7200 FETT
In July, 2004, ground testing was under way on the GP7200 engine. Prior to service entry, the GP7200 program will accumulate more than 20 000 endurance cycles and 7 000 hours of operation on eight test engines. (55) During ground testing, the engine Alliance's GP7200 engine is exceeding performance expectations for specific fuel consumption and exhaust gas temperature margin. First GP7200 engine reached 88 000 lbs (391kN) thrust exceeding the 70 000 lbs (311kN) thrust required for entry into service. The second development engine began ground testing with a 700 cycle's endurance test to evaluate hardware durability at operating conditions more severe than expected in airline service. The FAR 33 certification follows an extensive ground and flight-test program that involved eight engines over 21 months. During its development and certification program the GP7200 ran some 7 000 cycles, 25 full-scale engine certification tests and more than 50 component tests and powered two flight-test programs on a flying test bed. The engine is initially certified at 76 500 lbs of thrust and has the capability to produce over 81 500 lbs with the same bill of material. During its certification program the engine was tested at thrust levels in excess of 94 000 lbs. (55)
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The Engine Alliance’s GP7200 engine is undergoing extensive testing at GE’s Peebles Test Operation
Additionally, Bruce Hughes, Engine Alliance president said "We put the GP7200 through as tough a test regime as any engine has ever faced. Even though the engine will be used on the four-engine A380, we tested and certified it to the same standards required for large twin-engine aircraft in ETOPS (Extended-Range Twin Engine Operations). This has been an outstanding team effort by the Engine Alliance, its parent companies GE and Pratt & Whitney, and its partners, MTU, Snecma and TechSpace Aero. Now we are ready to get on with flight-testing and certification on the A380."
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Pratt & Whitney's full-scale Geared Turbofan demonstrator engine during a nacelle system fit check.
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Engine Alliance GP7200 being tested at AEDC (Left), Icing test facility at AEDC (Right)
First GP7200 flight test commence in December, 2004 being fitted to Boeing 747. This first flight took nearly three hours especially for initially assessing the engine operation as well as gathering propulsion system data on the nacelle and accessories. The initial series of seven flight tests will wrap up by the end of 2004. The GP7200 engine has been tailored to satisfy both current and future thrust requirements of the A380 family of aircraft. (56) Engine Alliance has reached a major milestone in the development of its GP7200 engine with delivery of the first four compliance/flight test engines for the A380. Nacelle and aircraft system components were installed in this engine. GP7200 engine provides 70 000 lbs of thrust for the A380 with capability to more than 80 000 lbs.
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Engine Alliance Delivers First A380 Engines to Airbus
In tests, engines showed that they performed flawlessly and have met all critical targets for performance, durability, noise and emissions. In-flight performance measurements confirms that GP7200 engine is the most fuel-efficient engine for A380 aircraft as a consequence of burning less engine fuel than Airbus Company's requirement. (57)
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After 16 months of flight testing, the engine Alliance GP7200 powered Airbus A380 finally received type certifications from the European Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA) in December, 2007. (57)
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Engine Alliance President Bruce Hughes (right) is shown presenting a collage of the program’s history to Airbus Executive Vice President Mario Heinen at the EASA certification ceremony in Toulouse, on December 14, 2007.
Type certification is an indicator that GP7200 ready for Airbus A380 after having accumulated 240 flights and 2 855 engine flight hours. Moreover, the GP7200 engine has amassed more than 5 250 hours and 17 760 cycles of endurance ground testing. The representative of Airbus Company, Mario Heinen, and Airbus Executive Vice President said at the EASA certification ceremony "The GP7200-powered A380 has been performing extremely well throughout the development and certification program, the aircraft is consistently meeting and often exceeding its design targets".
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17.2.2. Qualification Tests 17.2.2.1. Bird Ingestion (FAR section 33.76) In June 13, 2005 - Engine Alliance successfully completed three separate bird ingestion tests with four 2.5 lbs flocking birds, a 5.5 lbs and an 8 lbs bird. During the test, the engine has not caused any severe of adverse condition including catch fire, release hazardous fragments through the engine casing, generate loads greater than ultimate loads or lose the ability to be shut down. 17.2.2.2. Rain and Hail Ingestion (FAR section 33.78)
According to CS-E 790(a)(1) requires that " The ingestion of large hailstones, with the engine at maximum continuous power/thrust, must not cause unacceptable mechanical damage or unacceptable power or thrust loss after the ingestion, or require the engine to be shut down ". The GP7200 was tested on this requirement and the result satisfied the regulation. However, there are two effects of the large hailstone ingestion should be considered: the mechanical damage due to the kinetic energy of the ice, and the ingestion by the engine of the corresponding mass of ice or water. (57) Power or thrust loss caused by the ingestion of ice or water: Ingestion of large hailstones does not adequately assess the effect of ice or water ingestion on the engine. This is actually evaluated by testing in accordance with CS-E 790(a) (2). Compared with CS-E 790(a) (1), much more liquid water and ice are ingested during testing in accordance with CS-E 790(a) (2). This ESF concerns only CSE 790(a) (1). The engine will be fully tested in accordance with CS-E 790(a) (2) and no equivalent safety finding is necessary to demonstrate the engine capability to ingest water or ice. (57) Power or thrust loss, or necessity to shut down the engine, caused of mechanical damage: The safety objective in term of mechanical damage is comparable with the one of CSE 800. Means of compliance other than complete engine test are accepted for CS-E 800, it is therefore reasonable to also accept these other means of compliance for CS-E 790(a) (1). Before publication, the ESF document will be revised to mention that, in such a case, the content of CS-E 800(f) (1), and related AMC, need to be taken into consideration when using these other means of compliance for CS-E 790(a) (1).
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17.2.2.3.
Vibration Test (FAR section 33.83)
Engine Alliance GP7200 vibration test has been tested in February, 2006. The first of four Engine Alliance GP7200 engines has been installed on the fifth A380 test aircraft. It has been published that the vibration tests have been successfully carried out trials including aerodynamics, and low speed at the same time. 17.2.2.4. Endurance Test (FAR section 33.87)
The GP7200 development engines had 150 hours block endurance testing. The eightengine GP7200 test program accumulated more than 15 000 endurance cycles. A representative of engine Alliance stated "Service ready". In addition to flight-testing, GP7200 factory engine endurance ground testing has amassed 4 349 hours and will accumulate an additional 3 000 cycles of maturity prior to entry into service. 17.2.2.5. Engine Over Temperature Test (FAR section 33.88)
Engine Alliance tested GP7200 to qualify this requirement by operating the engine at maximum rating's steady state approximately 970 Celsius. Moreover, GP7200 has been tested for more than five minutes with the turbine gas temperature at maximum permissible rpm about 1002 Celsius. 17.2.2.6. Blade Containment Rotor Unbalance Tests (FAR section 33.94)
Engine Alliance GP7200 has successfully conducted fan blade-out containment in November, 2004. During the test, the GP7200 showed that the engine could hold the damage without any failure of the attachments and catching fire.
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18.Hydraulic System
Weight is one of the most concerned issues in aircraft manufacturers. Every extra pound contributes to fuel costs and also affects to the bottom line for the airlines. Airbus Company makes a challenge decision by changing 3 000 psi hydraulic systems as other passenger aircraft to 5 000 psi hydraulic systems. Eaton Corporation was selected by Airbus Company to provide the 5 000 psi hydraulic power generators for the A380. The system is made of: 1. Eight Vickers PV3-300, 2. Thirty one engine-driven hydraulic pumps, along with 3. Four AC motor pumps and 4. Electronic control and protection systems. The pumps are pressure-compensated variable displacement type, and deliver 42 gpm at 3775 rpm.
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A380’s Hydraulic system (5000 PSI)
There are two outstanding aspects set this pump apart. First is the disengagement clutch, in case of a pump cannot operate while on ground, the clutch can segregate the pump from the system and this will allow airplane to be dispatched by using the remaining seven pumps. Moreover, Phil Galloway, engineering manager of Eaton said "The pump cannot re-engage except on the ground, via manual means." Secondly, the PV3-300-31 by itself provides low noise and pressure pulsation. It provides pressure in a given 5 000 psi system might vary from 4 900 to 5 100 psi.
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Switching to use 5 000 psi hydraulic systems is not easy tasks to do due to some extremely serious pump design issues at higher pressure as shown below:
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Stresses Material Selection Deflections Pressure Time Velocity Factors Pressure Balances Efficiency, and Pressure Pulsations
Computational fluid dynamics is also used to minimize pressure drop in critical areas. For material selection, the 5 000 psi hydraulic systems almost rely on steel or titanium. "Pulsations can be minimized with the use of pulsation attenuators, essentially fluid volumes added to the outlet line of the hydraulic pump. The size of the attenuator is a function of the size of the pump and the amount of attenuation desired. The drawback to large attenuators is that the weight can be significant, as a high pressure volume is required" said by Phil Galloway, Engineering Manager of Eaton. Messier-Bugatti is another company which relevant to hydraulic system development for Airbus A380, they also focus on developing high-tech components which demanded sophisticated computer modeling.
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EHA mini-pumps for A380 flight control: ailerons, rudder and elevator
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18.1.
Equipment Tests
There are several components which relevant to A380's hydraulic system and these components are also investigated by many companies. Being easy to classify, this section will divide components by company. 18.1.1. Eaton Corporation
In October, 2001 - Airbus has selected diversified industrial manufacturer Eaton
Corporation to provide the hydraulic power generation system for the world's largest commercial airliner, the A380. According to this contract, it allows Airbus Company to achieve significant weight savings from fluid conveyance and actuation component volume reduction throughout the aircraft's structure. (58) The A380 hydraulic system integrates a total of eight Engine Driven Pumps (EDP). This architecture allows having one EDP as a go item which means the aircraft can be dispatched normally with one off-line EDP while using the remaining seven pumps.
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A380 Hydraulic System Block Diagram
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18.1.1.1.
Engine Driven Pump
There are eight Eaton Vickers brand Engine Driven Pumps (EDP) on the A380 which provide the main hydraulic power for the 5 000 psi system. During the test, it showed that in each EDP delivers a rated flow of 160 L/min at 3775 rpm. Moreover, this pump integrates an 11 piston rotating group coupled with a spherical type attenuator, a boost impeller, and a scavenge pump. (59)
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18.1.1.2.
AC Motor Pump
The 21.3kw 5 000 psi AC Motor pump is the largest developed to date for an aircraft. After testing each Eaton Vickers brand AC Motor pump by powering 115 VAC 400 Hz to each Vickers, it gave a result that can deliver a max flow of 38 L/min with a constant horse power characteristic. (59)
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18.1.1.3.
Fire Shut-Off Valve (FSOV)
There are four Fire Shut-Off Valves which fit to the A380. These valves are used to shut-off the hydraulic line at the pump inlet in the event of major system or engine failure. The FSOV is fitted with size 32 hydraulic ports and provide a nominal flow of 350 L/min under a pressure of 220 psi from the testing. (59)
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18.1.2. Messier-Bugatti Messier-Bugatti can analyze system's hydraulic behavior in terms of performance, stability and robustness due to the LMS Imagine Lab Ground Loads solution modeling and analysis capabilities. These results were used to establish the sizing, output and other product specifications for the entire hydraulic power generation system including the tank, pump and accumulator. (60)
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A380 nose wheel steering AMESim simulation/test bench results comparison AMESim model matches real system behaviour.
Messier-Bugatti simulated the behavior of the electro-hydraulic system for the A380 which validate system power-generating performance and enable engineers to accurately size components early in development.
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Local Electro Hydraulic Generation System (LEHGS) with its Electronic Control Unit (ECU)
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18.1.3. FR-HiTEMP This is one of the UK's leading aerospace component manufacturers, which specializes in fuel, ducting, actuation, and control systems for aero engines, missiles and military vehicles, supplies most of the world's aircraft manufacturers and also supports airlines. During the test, two special Carbolite thermal cycling chambers were installed to test hydraulic systems on the A380. There are some components of hydraulic system position around the massive Trent 900 or GP7200 engines, while other parts are in the wings. These components usually have temperature from -55 degrees to +90 degrees Celsius. (61) The thermal chambers are used to replicate the service temperatures while components are subjected to pressure impulse testing up to 6 000 psi (400 bars). The chambers have a thermal range from 70 degrees Celsius to+150 degrees Celsius.
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Thermal chambers test Airbus hydraulic systems
Liquid nitrogen, pressure relief valves and exhaust vents are used to cool the chambers while heating is by mineral-insulated metal-sheathed elements. Temperature stability and uniformity are better than ± 5 degrees Celsius. (61)
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19.Structural and Design
This topic contains only ground tests which are performed before flight tests so the investigator must significant concern this phase. There are several new components and new technologies in ground tests due to A380 unusual design features. In April 2003 – Airbus is about to start structural assembly of the first major A380 components around European plants, as half of design drawings has been released to manufacturer. At the same time, new wing plant was almost finished, and wing assembly was due to be fit together by October, 2003. The first wing skin/stringer attachment was successfully completed. Charles Champion, Airbus vice-president A380 program said "Around 18 000 of the 35 000 design drawings have now been released to manufacturing and all the basic structural design drawings have been released. We are now concentrating on detail design such as systems, plumbing and wiring bundles”.
19.1.
Ground Tests
Ground tests are classified into three main sections: 1. Fatigue tests 2. Wing tests 3. Cabin tests. In each test, it shows how Airbus satisfies the safety and reliability. 19.1.1. Fatigue Tests Airbus Company has awarded a contract with Industrieanlagen Betriebsgesellschaft (IABG) for testing the fatigue life tests for the A380. Prof. Rudolf Schwarz, Chairman of the IABG Management Board said "We have been involved in the fatigue tests on the Airbus aircraft since the first A300 at the beginning of the 1970's. The cooperation with IMA in Dresden has already proven itself Excellency during the current tests on the A340-600 here in Dresden and contributes to the fact that Germany enjoys an outstanding reputation in Europe for the performance of fatigue tests on large and complex aircraft structures”. In September 2004 – IABG made preparation for the most extensive fatigue tests on A380 aircraft. This test was located in Dresden, Germany by shipping five sections of the new Airbus A380 from Hamburg. The structure then be assembled and integrated in the IABG test facility. (62)
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Testing aim was to verify the fatigue life of the complete aircraft fuselage for the planned operational period of about 25 years. The total period of test is approximately 26 months. The standard safety requirement with the design target of 19 000 flights but this test expected to simulate the loads for 47 500 flights which are more than three times of the requirement. The new process which created by IABG was used in testing A380 and was used on A340-600.
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Fatigue strength test on the new wide body aircraft Airbus A380
According to IAMG, overall facilities consist of a comprehensive test rig accommodates the test structures, integrated hydraulic load unit with almost 200 cylinders where these hydraulic cylinders simulate, in conjunction with specially developed load induction systems, similar loads on the test structure as they would occur in operational flight. IAMG facilities have Control and monitoring system of the 250 channels, as test structure loading is recorded using a metrology unit which permits the measurement and recording, on 7 200 channels mainly on material strain, pressure, temperature and deformation values during the course of the test. In June 2005 – IAMG representative, Klaus Woithe and Airbus Project Manager stated that the first 5 000 simulated flights have gone off smoothly up to this date. A hydraulic loading rig equipped with 182 pulling simulated the load placed on the primary structure of the A380 in flight operation. "Whiffle trees" is a device that has been used to load the structure over 1 700 points. Whiffle trees simulates structure as real life loads affecting the aircraft such as the wings have to be able to withstand 4.5 meters upward deflections and 1.5 meters for downward deflections. Applied forces were simulated as 160 tones that act on each of the four main A380 undercarriages when in service. (63)
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The whiffle tree structure used to do a torsion test
In May, 2006 – Airbus Company reached a milestone in Dresden, Germany. The fatigue tests on the A380 reached 10,000 flight cycles. During the test it can examine the A380's structural behavior by simulating structural stresses over a very condensed period of time. Charles Champion, Airbus COO and Head of the A380 program declared that" This major milestones is underlining the excellent progress of our A380 test program and 10 000 flight cycles is already twice as much as we need for certification”. The fatigue test has passed the 15 000 simulated flights which is three times the 5,000 flight needed for certification in July, 2006. In this test, hydraulic actuators were attached to the aircraft structure and loads were applied to the wings and the fuselage to simulate forces during a typical flight. (64) 19.1.2. Cabin Tests The dimensions of the Superjumbo allow for both flexibility and creativity in cabin design. The A380 provides 50 percent more floor space than the B747 but only 35 percent more seats. The remaining 15 percent of space is available for customized areas without penalizing the seat count. The assembly process is very complex due to the configuration of one deck which differs from other, with different combinations of seating classes.
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Typical A380 cabin configuration
In March 2006 – Airbus Company successfully completed the first extensive ground cabin tests in a fully equipped Airbus A380. It took five hours in this test by using 474 passengers and 20 crew members simulated a 15 hours flight. During flight, Both passengers and crew members tried all cabin systems such as the water and waste system, kitchens and air conditioning system, and in-flight entertainment system. (65)
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Emirates A380 First-Class private suites
Airbus Company assigned individual tasks for all passengers on board test flight for performing at certain intervals in order to simulate a maximum stress on certain cabin
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systems. One of the tasks is to test the performance of in-seat power supply (220v/110v switchable) by using notebooks. All of the cabin managements such as full meal service, and galley and trolley lift operations were included in this test. (65) 19.1.3. Wing Tests In each A380 wing has eight spoilers which are located on the top of the wing. In landing condition, Airbus A380 weight approximately 380 tons and the landing speed is around 280 km/h. In landing condition, all eight spoilers are extended by means of hydraulic cylinders for helping to achieve the drastic reduction in speed. According to Airbus Company, "The function of the extended spoilers is twofold: firstly, they reduce lift while allowing enhanced wheel grip, as in Formula 1 vehicles, and secondly, they increase aerodynamic drag, thereby taking on a considerable portion of the overall required braking effect. Moreover, the spoilers can also be used for specific operations during flight, such as supporting the control flaps while carrying out flying maneuvers, or causing a rapid drop in speed or altitude”. In May, 2005 – IABG tested spoilers on the new Airbus A380 where they set up two main tests: static and dynamic tests. Each test consists of a test rig, either nine or seven hydraulic cylinders, and four devices known as "whiffle trees", which simulates the distribution of aerodynamic forces. (66)
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Setup for the Spoiler Test of the Airbus A380
Static tests initially involve simulating the limit load that can conceivably be reached during flight, then load is increased to one and a half times this limit, or ultimate load. The spoilers must be capable of taking this load.
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Dynamic tests involve testing whether the spoilers can undergo 19 000 simulated flights without showing signs of fatigue. This represents the intended service life of the A380, for this purpose, components are loaded with every conceivable force that could cause damage over time. IABG simulates loads not only over an individual aircraft service life, but also over a double aircraft service life for one of the spoilers, and 3.6 times a service life for the other. Furthermore, the components are weakened by artificial aging and artificial defects. The fatigue tests are interrupted at regular intervals in order to inspect the test samples for possible fatigue damage. (66) In February, 2006 – Airbus A380's wing was tested in Toulouse, France. The wing from static test specimen suffered a structural failure below the ultimate load target during the trials. (67) After completing "limit load" tests which is the maximum loads likely to experienced by the aircraft during normal service, the greater loads have been applied to the specimen towards the required 1.5 times the limit load and the finite element method (FEM) has been used to calculate the load requirements. The result of this test was the failure at a point between the inboard and outboard engines between 1.45 and 1.5 times the limit load. Alain Garcia, Airbus executive vice president engineering declared after the test finished that "This is within 3% of the 1.5 target, which shows the accuracy of the FEM and the ultimate load trial is an "extremely severe test during which a wing deflection of 7.4m (24.3ft) was recorded”.
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Airbus has been running load trials on a full scale A380 static test specimen in Toulouse since late 2004
European Aviation Safety Agency (EASA) reflected this test by said that the maximum loading conditions were defined in the A380 certification basis. The aircraft structure was
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analyzed and tested to demonstrate that the structure can withstand the maximum loads, including a factor of safety of 1.5. (67) The FEM was used to prove the adequacy of the A380's structure on production aircraft. Airbus had refined the structural design for subsequent aircraft due to increased weights, according to Alain Garcia, Airbus executive vice president engineering.
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Airbus performing bending test on A380 wing
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A380 FEM wing model
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20.Flight Tests
The maiden flight test for Airbus A380 was in April, 2005. The world's largest commercial aircraft successfully took off with six crews and approximately 20 tones of test equipment from Blagnac International Airport in Toulouse which is its production site. This flight took about four hours circling the Bay of Biscay. For this first flight, Airbus A380 took off at weight of 421 tones or 928 300 lbs which is the highest weight ever of any civil airliner. Four Rolls-Royce Trent 900 engines powered the A380 to fly on the sky. Thousands of parameters which important to enable in-flight performance analysis were recorded during this flight test. (68)
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A380 Super Jumbo Jet Makes Maiden Flight
Claude Lelaie, test pilot said after A380 landed "You have seen a lot of ground tests, a lot of wind tunnel tests, simulators -for the first time you can see all the systems working together in the real world in the air, a new page of aeronautical history has been written. It is a magnificent result for European industrial cooperation”. The first flight is the beginning of a flight test campaign involving as many as 2 500 hours of test flights on a total of five development aircraft. This rigorous sequence of test flights will lead to the certification of the A380 by the European and US airworthiness authorities which allow the world's largest commercial airliner to enter into service in the second half of 2006 with Singapore Airlines being a first commercial operator.
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MSN 001 First test aircraft, to be retained by Airbus MSN 002 Flight test aircraft. Third aircraft to fly. Will be delivered to Hamburg later this year and will be used first for evacuation tests, then fitted with working cabin (including Thales IFE) for “early long flights” and then for route proving. Will be refurbished and delivered to Etihad MSN 003 First weight-conforming aircraft and first aircraft for Singapore Airlines MSN 004 Flight-test aircraft. Second A380 to fly. Workhorse for performance trials. Will be refurbished for Etihad MSN 005 Customer aircraft MSN 006 Customer aircraft MSN 007 Fourth test aircraft to fly, second with working cabin (Panasonic IFE). Will be used for route proving, and later re-engined with GP7200 engines to join MSN 009 for GP7200 route proving. Will revert to Trent power and be refurbished for Etihad. MSN 008 Singapore Airlines MSN 009 Flight-test aircraft. Leads certification with GP7200 engines. Will be re-engined and refurbished for Etihad
Airbus A380 flight test schedule from MSN 001 to MSN 009
20.1.
MSN 001
There are five A380s in the flight test program. MSN 001 heavily instrumented and fitted with a double row of ballast water tanks which completed envelope expansion and retained by Airbus for further testing. MSN 001 explored the flight envelope, evaluate the cruising performance, the noise impact, determine Vmu and complete accelerate-stop tests and X-wind behavior. In December, 2005 – The demonstration of the A380's maximum design speed (Vmd/Mmd) reaching 0.96 Mach as it shows that A380's flight envelope has been successfully marked. During the test, A380 dived to around 39 000ft (11 900m) and reached 0.96 Mach with pitching down attitude was only 7 degrees. The noise evaluation has been successfully tested at Moron airbase in Spain for four days. It showed from this test that the A380's external noise can be achieved with the current configuration. The aircraft complete over 100 flyovers to measure approach and take-off noise.
20.2.
MSN 002
According to Airbus Company, MSN 002 is the next test aircraft in the manufacturing sequence with testing cabin systems especially on over long flights. This program took approximately seven months which divided into two sections. First is preliminary test which took one to two months. Secondly, a full complement of passengers from Airbus employees was carried in the later four to five months. This allowed environmental control systems, in-flight entertainment systems, and galleys.
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During the flight, the Airbus A380 was outfitted at the manufacturer's Finkenwerder facility with an airline style 474 seats cabin layout. The aircraft was then used for a 500h static virtual flight cabin systems tests. However, before being completed the cabin was modified into a high-density 853 seats arrangement for the evacuation trial.
20.3.
MSN 004
MSN 004 also carried heavy instrumentation and was the workhorse for performance testing, for two reasons. First is that Rolls-Royce Trent 900 engines are to a later build standard. Secondly because it is the first flight-test aircraft which is close to the specified manufacturer's empty weight (MEW). In October 2005 – MSN 004 joined the flight test program. Fernando Alonso, Vice-president Flight tests said “It completed the main evaluation of cruise performance on 9 November and there are complementary evaluations continuing until the end of December, and A380 could end up cruising slightly faster than its nominal published speed of 0.85 Mach”.
20.4.
MSN 007
MSN 007 was due to ferried to Hamburg for its cabin installation in February 2006. It was set to undertake the route-proving program and later be re-engined to conduct route proving of the Engine Alliance GP7200 powered version. MSN 007 is the fourth test aircraft that took 300 hours of route proving. MSN 007 had a Panasonic system which differs from MSN 002 that had Thales IFE system.
20.5.
MSN 009
Assembly of the main Engine Alliance flight test aircraft has been successfully completed in MSN 009. According to Airbus, the certification of A380 powered by GP7200 was received in the first quarter of 2007 to enable deliveries to begin to launch customer. MSN 009 joined MSN 007, which fitted with GP7200 after its initial tests and used for routeproving with the Alliance engine.
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20.6.
Crosswind Landing Flight Test
In October, 2007 – Airbus A380 started crosswind landing certification tests in Keflavik with 40 to 50 knot crosswind. There is a technique which leads to the success flight test; the technique is to fly crabbed down to flare height then kick the rudder to align the nose. Some crab at touchdown is acceptable and will be cancelled as the main gear also aligns the bird with the runway. (69)
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A380 Crosswind landing
20.7.
Natural Gas as a Fuel Alternative
Airbus believes that fuel alternative will become more useful in around 2015, due to the Airbus decided to have a chance for flying A380 with natural gas. In February, 2008 – Flight test took about 3 hours flight by a double-decker A380 flew from Filton, Britain to Toulouse, Airbus headquarters. The giant aircraft's unmodified engine was powered by a blend of gas-to-liquid (GTL) fuel and kerosene. (70)
20.8.
High Altitude and Hot Weather Testing
In October, 2006 – Airbus A380 powered by GP7200 returned to Toulouse after completing high altitude and hot weather testing in Africa and the Middle East. A380 landed in Addis Ababa, Ethiopia where the airport is 7 627 feet (2 325 meters) above sea level. For hot weather campaign, Airbus A380 confronted the conditions of up to 40 degrees Celsius. The aircraft performed five test flights to evaluate engine performance at high altitude conditions, including engine takeoff performance characteristics, ground staring and transient operations.
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A380 during hot weather testing
Bruce Hughes, President of the Engine Alliance said "We continue to be very pleased with the GP7200's in-flight performance, and the engine's fuel burn performance continues to track at or better than our specification to Airbus and all other parameters are performing just as we expected, even in the punishing high and hot conditions of Addis Ababa and Al-Ain”.
20.9.
Cold Weather Trails
In February, 2006 – Airbus A380 returned from Iqaluit, Canada after completing cold weather test. During testing, the full functionality of the systems had been tested under extreme weather conditions of up to minus 30 degrees Celsius for five days.
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A380 during cold weather testing
Test included powering up the aircraft, the engines and hydraulic systems after a full 12-hour period at such low temperatures. The batteries were taken away overnight and kept in a warm area. Batteries were reinstalled onboard the aircraft for the tests in the next morning. (71)
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21.Route Proving
Airbus A380 Technical route proving is the last required step to Type Certification after proving its potential in each of equipment tests, qualification tests, ground tests, and flight tests. There are two main routes proving which are A380 powered by Trent 900 (MSN 002), and A380 powered by GP 7200 (MSN 009). The technical route proving started on 13th November 2006 as it’s a great opportunity to show the people worldwide Airbus A380 function and reliability including key airports. During this test, the A380 was powered by four Rolls-Royce Trent 900 engines which used the flight test program MSN 002 where it departure from an airbase in Toulouse, France and flew to ten major international airports in four trips. Singapore and Seoul were the first two stops on 14th November and 15th November. The second trip operated in 18th November in Hong Kong and followed by 19th November in Narita. Third trip was in two cities in China Guangzhou and Beijing on 22nd November, and 23rd November, respectively. (72)
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New York's JFK airport was the first destination of the A380 Route Proving exercise (Left), The A380 visited Hong Kong on Saturday 24 March 2007 during its second route proving trip (Right)
The last trip was the longest trip out of four as it flew around the world via South Pole and North Pole. The trip started from Toulouse to Johannesburg in 26th November and two day later arrived at Sydney via South Pole. A380 route proving showed aircraft performance by flying long-range flight with maximum payload with a maximum take-off weight approximately 555 tones/ 1 223 565 lbs. A380 took only 16 hours from Johannesburg to Sydney covering a distance of 7896 nm/ 13 512km. On 29th November, A380 flew across the Pacific to Vancouver and then returned back to Toulouse via the North Pole. (72)
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The second route proving which was powered by GP7200 started on 26th September 2007. This route proving was also divided into four trips stopover, South America, North America, Middle East and Asia-Pacific. (73) It also commenced for an airbase in Toulouse, France to Bogota, Colombia on 26th November where the aircraft had only spent a day in Colombia and then flew back to Toulouse. The second trips began from 2nd October to 5th October as it headed to three cities in USA, Windsor Locks (Connecticut), Hebron (Kentucky) and San Francisco (California). Third planned trip started on 8th to 13th October where the aircraft spent five days flying to Dubai (United Arab Emirates), Melbourne (Australia), Manila, and Luzon (Philippines) and back to Dubai (United Arab Emirates). The last trip was tested on 15th October; the Airbus A380 flew to Bogota (Colombia), Vancouver (Canada), and Osaka (Japan) and then went back to Toulouse on 19th October. After finishing these two main routes proving trips, Airbus A380 was turned around under normal airline operating conditions. (73)
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22.Conclusion and Recommendations
Airbus A380 is the world largest commercial aircraft at this moment, so there is no doubt that people all over the world are focusing on this particular aircraft and would want to stay in contact with. In conclusion this lead aerospace engineer or others who are related to this project should address safety and security issues facing the A380 in service. In this project I’ve started my second part where I begun to talk about the use of V&V process to test the safety and reliability issues. There are 5 main tests used for analysis in this paper: 1. Equipment tests 2. Qualification tests 3. Ground tests 4. Flight tests 5. Rout proving In each test contains details and information from five main criteria that break, Landing gear, break, and steering system, Powerplant, Structural and Design, and Hydraulic system. Airbus A380 is only few years old where information is not easily found even on Internet and published books. In addition, it is very difficult to find in-depth information. This may occur, in connection with the Airbus does not want to announce it in detail or being confidential. Safety and reliability issues are very important factors in the aerospace and aviation industry, for that reason I hope this thesis useful was for those who much enthusiast about the Airbus A380 and the process it went through to satisfy airworthiness regulations. Airbus has done a great job in production of its state of art A380 where it was late in delivery but aircrafts reviewers think it was worth of wait due to high technology and precision built that leads to low maintenance cost and environment friendly aircraft.
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A380 CFD Model
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STUDENT NAME: IBRAHIM AL NAJJAR STUDENT NUMBER: S3158405 ACADEMIC SUPERVISOR: DR. HE REN
SCHOOL OF AEROSPACE, MECHANICAL AND MANUFACTURING ENGINEERING
Abstract
Nowadays aerospace and aviation industry is expanding very rapidly to fill the gaps of consumers' needs, as the industry expand, problems would also increase due to the high demand that would lead companies to increase their line of production where it will also increase the percentage of errors in production due to lack of time. Aerospace and aviation organizations and authorities sets certain rules and regulation to minimize errors from happening even before reaching the production line, It begin from a concept design of an aircraft as it is a synthesis of different disciplines like aerodynamics, flight mechanics, aeronautical structures, etc. Allowing Airbus A380 to be operational in normal air traffic, it is necessary to demonstrate that its design and construction are in compliance with the applicable requirements; the verification of such compliance is entrusted to the competent authorities. Airworthiness introduce aerospace engineers into a world consisting on one hand into the aircraft's designing, manufacturing and operation firms and on the other hand into airworthiness authorities, both hand should work together and they should aim at a common goal "Flight safety". Airbus A380 is the new latest and largest civil aircraft in the aviation market. This type has a novel or unusual design features when it’s compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. Many of these novel or usual design features are associated with the complex system and the configuration of the airplane. For these design features, the applicable airworthiness regulations do not contain adequate or appropriate safety standards. My thesis is to achieve an understanding of the fundamental process of Airworthiness and Safety Validation Verification Methods in A380 Program and to identify and investigate the main reasons of failure in this aircraft and how would we be able to certify it and make is free to fly, so we can use the FAA airworthiness regulation and update it so it can meet our new A380 airworthiness requirement.
I
Declaration
I certify that except where due acknowledgement has been made, the work is that of the author alone; the work has not been submitted previously, in whole or in part, to qualify for any other academic award; the content of the thesis is the result of work which has been carried out since the official commencement date of the approved research program; any editorial work, paid or unpaid, carried out by a third party is acknowledged; and, ethics procedures and guidelines have been followed.
Ibrahim Al Najjar 25/10/2010
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Acknowledgement
Foremost, I would like to express my sincere gratitude to my supervisor Dr. He Ren for the continuous support of my final year project work, for his patience, motivation, enthusiasm, and immense knowledge. His guidance helped me in all the time of research and writing of this thesis. Besides my supervisor, I would like to thank Airbus, for their help, support while some information was taken from them and insightful comments. My sincere thanks also goes to Emirates Airlines for offering me the summer internship opportunities in their A380 facility, leading me working on diverse exciting project. In this project, I’ve tried my best to collect information and data from every single string related but it may still be lacking information due to unfound source or confidential information. Last but not the least; I would like to thank my family members, for supporting me and because of them I ended up taking aerospace engineer as a career.
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List of Figures and tables
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. International Civil Aviation Organization Logo http://www.whatsonxiamen.com/news_images/3345icao.jpg CAA Logo http://www.flightline.co.uk/travelnews/wp-content/uploads/2007/11/caa_logo_small.gif Joint Aviation Authorities Logo http://www.ifalda.org/Images/Organization%20Logo%20Folder/JAA%20Logo.jpg European Aviation Safety Agency Logo http://www.umcntp.co.id/images/logo/EASA_EU.png Federal Aviation Administration Logo http://servus.cocolog-nifty.com/blog/images/2008/10/10/0409faa_logo.jpg Current Technology on A380 Engine http://www.enginealliance.com/images/gpintro_05.gif Validation and Verification Method http://www.buzzle.com/editorials/4-5-2005-68117.asp Airbus A380 Parts Assembly Early Stage of A380 as A3XX http://timeforflight.tripod.com/000056.gif Airliners Order of A380 http://en.wikipedia.org/wiki/List_of_Airbus_A380_orders_and_deliveries A380 Dimensions http://www.airbus.com/en/aircraftfamilies/a380/a380/specifications/ A380 Basic Operating Data http://www.airbus.com/en/aircraftfamilies/a380/a380/specifications/ A380 Design Weights http://www.airbus.com/en/aircraftfamilies/a380/a380/specifications/ A380 External Dimensions http://www.hudihudi.com/goodones/airbus/airbusdesign.jpg Landing Gear Systems Testing http://i15.photobucket.com/albums/a357/thezeke/A380%20systems/bea0715e.png The Body Wheel Steering http://i15.photobucket.com/albums/a357/thezeke/A380%20systems/0168becd.png A380 Landing Status http://i15.photobucket.com/albums/a357/thezeke/A380%20systems/94415de2.png A380 Section 19 Systems Integration and Assembly http://www.aint.com/images/a380_dscn0915.jpg A380 GP7200 Cutaway http://turbofanatic.com/hosting/ljpictures/randompics/gp7000_cutaway_high.jpg Inside an Airbus A380 while at testing http://c0170351.cdn.cloudfiles.rackspacecloud.com/72_14_m.jpg Airbus A380 wing test http://www.flightglobal.com/assets/getAsset.aspx?ItemID=11513 Celebrating A380 http://www.skycontrol.net/UserFiles/Image/BusinessGA_img/200612/200612airbus-A380-iso.jpg A380 Landing Gear http://cdn-www.airliners.net/aviation-photos/middle/2/5/6/0965652.jpg Landing Gear at testing stage http://images.smh.com.au/2009/04/08/467150/Airbus-Landing-Gear-600x400.jpg A380 Structure http://borithlong.files.wordpress.com/2009/09/airbus-a380-11.jpg Engine examine and testing http://www.airportkosice.sk/image/image_gallery?img_id=865 A380 hydraulic unit http://www.messier-bugatti.com/IMG/jpg/hs0013nblocorient_ra_a380-230-2.jpg A380 break manifolds http://www.messier-bugatti.com/IMG/jpg/hf0041n.jpg A380 Skinless http://static.photo.net/attachments/bboard/00C/00Cpe5-24598184.jpg A380 Taxing http://www.machtres.com/ab380-006.jpg V & V Process http://www.buzzle.com/editorials/4-5-2005-68117.asp V & V Process http://www.informatik.uni-bremen.de/~tsio/papers/icstest2005_ott_hartmann-abstract.pdf A380 gear’s arrangement http://bp0.blogger.com/_JAPZLIogqvA/R3I4a1HtzPI/AAAAAAAAAIQ/yqCWY8eE2WM/s400/A380_wheel.gif A380 Extension/Retraction System http://ic2.pbase.com/g3/36/640536/2/88941012.duDJRdzS.jpg Wheel and Brake System Integrated Components http://www.messier-bugatti.com/IMG/jpg/freinelec1.jpg A380 Wheels, tires and brakes http://cdn-www.airliners.net/aviation-photos/middle/2/5/6/0965652.jpg Nose landing gear drawing http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_06_05_LandingGear.pdf Nose landing gear parts http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_06_05_LandingGear.pdf Nose Wheel Steering NWS http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_06_05_LandingGear.pdf Six-wheel landing gear system weighs approximately 12.000 pounds and is more than 25 feet long when fully extended http://www.sandvmag.com/downloads/0811obse.pdf The major mode shapes extracted from the test data were used to verify finite-element landing gear models at Goodrich and supported structural investigations at Airbus http://www.lmsintl.com/download.asp?id=9D8D8D1727E5-4C2A-9E06-90B780FF5C92 Selecting the modes of landing Gear http://www.lmsintl.com/download.asp?id=9D8D8D17-27E5-4C2A-9E0690B780FF5C92
42.
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43. Supporting landing gear and full aircraft simulations http://www.lmsintl.com/download.asp?id=9D8D8D17-27E54C2A-9E06-90B780FF5C92 44. Highly accelerated lift testing (HALT) http://www.geaviationsystems.com/About/Technical-Papers/Literature/A380landing-gear-extension-and-retraction.pdf 45. Three A380 electromechanical uplocks http://www.geaviationsystems.com/About/Technical-Papers/Literature/A380landing-gear-extension-and-retraction.pdf 46. A380 Hydraulic unit and brake manifolds http://www.messier-bugatti.com/article.php3?id_article=321%20&lang=en 47. A380 BTMS & TPMS http://www.messier-bugatti.com/rubrique.php3?id_rubrique=60&lang=en 48. Trent 900 Cutaway http://www.nickelinstitute.org/multimedia/magazine/March_2007/Turbines/Trent-900-cutaway600.jpg 49. Trent 900 Bird Strike Testing http://www.rolls-royce.com/Images/whittle_tcm92-5495.pdf 50. Trent 900 water ingestion test http://i14.tinypic.com/42sthxk.jpg 51. A380 Testing in hot weather conditions http://gulfnews.com/polopoly_fs/26-bz-airbusa3801-5-jpg1.258406!image/1840445697._gen/derivatives/box_475/1840445697. 52. Trent 900 bird strike test http://www.investis.com/rollsroyce/presentations/numis.pdf 53. Trent 900 water ingestion test http://i.ytimg.com/vi/faDWFwDy8-U/0.jpg 54. Tent 900 EMU http://www.ipl.com/pdf/pc022.pdf 55. Trent 900 fan blade-off test http://www.investis.com/rollsroyce/presentations/numis.pdf 56. Engine Alliance GP7200 http://australianaviation.com.au/wp-content/uploads/2010/08/article5-image1-full.jpg 57. Final assembly of the first GP7200 http://www.enginealliance.com/images/030404_11.jpg 58. Engine Alliance GP7200 FETT http://www.enginealliance.com/images/040604_12.jpg 59. GP7200 engine is undergoing extensive testing at GE’s Peebles Test Operation in Ohio http://www.sae.org/aeromag/techfocus/02-2005/2-25-1-18.pdf 60. Pratt & Whitney's full-scale Geared Turbofan demonstrator engine during a nacelle system fit check http://www.pw.utc.com/StaticFiles/Pratt%20&%20Whitney/News/Press%20Releases/Assets/Images/gtf-nacelle-fitcheck.jpg 61. GP7200 Tested at AEDC and icing test http://www.arnold.af.mil/photos/mediagallery.asp?galleryID=4551 62. Engine Alliance Delivers First A380 Engines to Airbus http://www.enginealliance.com/images/img_092905.jpg 63. GP7200-powered A380 Receives FAA, EASA Type Certifications http://www.enginealliance.com/release121407.html 64. A380 5000 PSI hydraulic system http://www.sae.org/dlymagazineimages/6728_6751_ART.jpg 65. EHA mini-pumps for A380 flight control: ailerons, rudder and elevator http://www.messier-bugatti.com/IMG/jpg/hmp0033n.jpg 66. Hydraulic system block diagram http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 67. Eaton’s Airbus A380 Components http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 68. Engine Driven Pump http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 69. AC Motor Pump http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 70. Fire Shut-Off Valve (FSOV) http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&allowInterrupt=1&RevisionSelectionMethod=LatestRelease d&Rendition=Primary&&dDocName=CT_193607 71. A380 nose wheel steering AMESim simulation/test bench results comparison AMESim model matches real system behaviour. http://www.lmsintl.com/download.asp?id=0FAEE181-15EB-4854-B1FF-D4AB47191AFA 72. Local Electro Hydraulic Generation System (LEHGS) with its Electronic Control Unit (ECU) http://www.lmsintl.com/download.asp?id=0FAEE181-15EB-4854-B1FF-D4AB47191AFA
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73. Thermal chambers test Airbus hydraulic systems http://www.carbolite.com/imagelib/fr_hightemp.jpg 74. A380 Fatigue test http://www.iabg.de/presse/download/bilder/highres/IABG_Versuchsaufbau_Airbus_A380_5-1024.jpg 75. The whiffle tree structure used to do a torsion test http://www.diomedes.co.za/pics/gallery/TestTubeTorsionSetup1.jpg 76. Typical A380 cabin configuration http://biztravelguru.com/blogs/business-travel-news/Qantas-A380-Seat-map-released.jpg 77. Emirates A380 First-Class private suites http://content.emirates.com/english/images/First%20Class%20Private%20Suites_media_545x320_12_tcm233354372.jpg 78. Setup for the Spoiler Test of the Airbus A380 http://www.iabg.de/presse/aktuelles/mitteilungen/images/200504_Airbus_A380_Spoiler_Test-1024.jpg 79. Airbus has been running load trials on a full scale A380 static test specimen in Toulouse since late 2004 http://www.flightglobal.com/assets/getAsset.aspx?ItemID=11513 80. Airbus performing bending test on A380 wing http://www.flightglobal.com/assets/getAsset.aspx?ItemID=11514 81. A380 FE wing model http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_01_30_A380.pdf 82. A380 Super Jumbo Jet Makes Maiden Flight http://www.dancewithshadows.com/business/images/a380/airbus-first-flight7.JPG 83. A380 Crosswind landing test http://fliiby.com/images/_thumbs/me_ovftb99fdv1.jpg 84. A380 during hot weather testing http://www.chinadaily.com.cn/cndy/attachement/jpg/site1/20100915/002564baf2f90dfa5a2f4a.jpg 85. A380 during cold weather testing http://www.puddy.co.uk/golf/DSC00201.jpg 86. A380 Route proving http://www.globalgiants.com/archives/2007/04/the_a380_makes.html 87. A380 CFD model http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_01_30_A380.pdf
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Table of Content
Abstract…………………………………………………………………………………………………………………………….………..…I Declaration……………………………………………………………………………………………………………………….………….II Acknowledgement……………………………………………………………………………………………………………………...III List of Figures and Tables…………………………………………………………………………………………………………….IV 1. Introduction………………………………………………………………………………………………………………………………….1
1.1. Flight Safety………………………………………………………………………………………………………………………………………………1 1.2. Airworthiness……………………………………………………………………………………………………………………………………………2
2. Airworthiness Organization and Authorities……………………………………………………………………………….…4
2.1. 2.2. 2.3. 2.4. 2.5. The ICAO (International Civil Aviation Organization)…………………………………………………………………………………4 The CAA (Civil Aviation Authorities)……………………………………………………………………………………………..……………4 The JAA (Joint Aviation Authorities)……………………………………………………………………………………………,…………….4 The EASA (European Aviation Safety Agency)……………………………………………………………………………………………4 The FAA (Federal Aviation Administration)……………………………………………………………………………………………….5
3. Literature Review.………………………………………………………………………………………………………………………..6
3.1. Review…………………………………………………………………………………………………………………………………..………………….6
4. A380 Concept Model History…………………………………………………………………………………………………….….8
4.1. Concept Model……………………………………………………………………………………………………………………………………….…8
5. Airbus A380………………………………………………………………………………………………………………………………….9
5.1. A380………………………………………………………………………………………………………………………………………………………...9 5.1.1. Aircraft Dimensions……………………………………………………………………………………………………………………….10 5.1.2. Basic Operating Data…………………………………………………………………………………………………………………….10 5.1.3. Design Weights………………………………………………………………………….………………………………………………….10 5.2. Landing gear System……………………………………………………………………………………………………………………………….11 5.3. Brake and Steering System………………………………………………………………………………….………………………………….12 5.4. Structural Design…………………………………………………………………………………………………………………………………….14 5.5. Powerplant………………………………………………………………………………………………………………….………………………….15
6. A380 Tests and Certification……………………………………………………………………………………………………….16
6.1. Overview………………………………………………………………………………………………………………………..……………………….16
7. A380 Type Certificate………………………………………………………………………………………………………………….17
7.1. Obtaining Type Certificate………………………………………………………………………………..………………………...………….17 7.2. A380 Type Certificate………………………………………………………………………………………………………………………………17 7.3. A380 Preparation testing for Type Certificate………………………………………………………………………………………….17
8. Federal Aviation Administration……………………………………………………………………………………………….…19
8.1. Background…………………………………………………………………………………………………………………………………………….19
9. Federal Aviation Administration (FAR 25: Landing gear)………………………………………………………….….20
9.1. 9.2. 9.3. 9.4. 9.5. 9.6. 25.721 – General………………………………………………………………………………………………………..……………………….….20 25.723 - Shock absorption tests………………………………………………………………………………..…………………………….20 25.731 – Wheels……………………………………………………………………………………………………………………………………..20 25.733 – Tires……………………………………………………………………………………………………………………………………….…20 25.735 - Brakes and braking systems……………………………………………………………………………………..……………….21 25.737 – Skis……………………………………………………………………………………………………………………....………………….21
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9.7. 25.487 - Rebounding landing condition……………………………………………………………………………………….………….21 9.8. 25.1515 - Landing gear speeds…………………………………………………………………………………………………….………….21 9.9. 25.729 - Landing gear extension and retraction system………………………………………………………………………….22
10. Federal Aviation Administration (FAR 25: Structural and Design) ……………………………..…………….….23
10.1. 10.2. 10.3. 10.4. 10.5. 10.6. 10.7. 10.8. 25.303 - Factor of safety………………………………………………………………………………………………………………….…….23 25.307 - Proof of structure……………………………………………………………………………………………………………….…….23 25.341 – Gust and turbulence loads…………………………………………..…………………………………………………….…….23 25.523 - Design weights and center of gravity positions….……………………………………………………………….…….23 25.603 – Materials……………………………………………………………………………………………………………………….….…….23 25.631 - Bird strike damage…………………………………………………………………………………………………………….…….24 25.681 - Limit load static tests………………………………………………………………………………………………..……….…….24 25.843 - Tests for pressurized cabins……………………………………………………………………………………………….…….24
11. Federal Aviation Administration (FAR 25: Powerplant) …………………………………………………..………….25
11.1. 25.903 – Engines………………………………………………………………………………………………………………….………………..25 11.2. 25.939 - Turbine engine operating characteristics………………………………………………………………………..….…….25 11.3. 25.963 - Fuel tanks: general…………………………………………………………………………………………………………….…….25 11.4. 25.1125 - Exhaust heat exchangers……………………………………………………………………………..………………….…….25 11.5. 25.1141 - Power plant controls: general……………………………………….……………………………………….……………….26 11.6. 25.1203 - Fire detector system……………………………………………..………………………………………………………….…….26 11.7. 33.76 - Bird ingestion……………………………………………………………………………………………………………………….…….26 11.8. 33.83 - Vibration test……………………………………………………………………………………………………………..…………..….27 11.9. 33.88 - Engine over temperature test…………………………………………………………………………………..………….…….27 11.10. 33.94 - Blade containment and rotor unbalance tests………………………………………………………….…….27
12. Federal Aviation Administration (FAR 25: Hydraulic System)…………………………………………………….…28
12.1. 25.1435 - Hydraulic System………………………………………………………………………………………………………….….…….28 12.1.1. Element design…………………………………………………………………………………………………………………….…….28 12.1.2. System design………………………………………………………………………………………………………………….……..….28 12.1.3. Tests…………………………………………………………………………………………………………………………………….…….28 12.2. A380 Hydraulic System…………………………………………………………………………………………………………………….…….29
13. Special Conditions (FAR 25: Structural and Design)……………………………………………………………………..30
13.1. 13.2. 13.3. 13.4. 13.5. Airbus Model A380-800 Airplane, Crashworthiness………………………………………………………………………….…….30 Airbus Model A380-800 Airplane, Airplane Jacking Loads……………………………………………….……………….…….30 Airbus Model A380-800 Airplane, Transient Engine Failure Loads………………………………………………………….31 Airbus Model A380-800 Airplane, Reinforced Flight deck Bulkhead………………………………………………….…….32 Airbus Model A380-800 Airplane; Fire Protection…………………………………………………………………………….…….32
14. Special Conditions (FAR 25: Landing Gear)…………………………………………………………………………………..33
14.1. Airbus Model A380-800 Airplane; Loading Conditions for Multi-Leg Landing Gear………………………………...33 14.2. Airbus Model A380-800 Airplane, Ground Turning Loads……………………………………………………………………….34
15. Verification and Validation Process (V & V)……………………………………….………………………………..………35
15.1. Verification……………………………………………………………………………………………………………………………………………..36 15.2. Validation……………………………………………………………………………………………………………………………………………...38
16. Landing Gear, Brake, and Steering System…………………………………………………………………………………..40
16.1. Equipment Tests…………………………………………………………………………………………………………………………………………………..42 16.1.1. Nose Landing Gear……………………………………………………………………………………………………………………..42 16.1.2. Main Landing Gear……………………………………………………………………………………………………………………..44
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16.1.3. Landing Gear Extension and Retraction System………………………………………………………………………….48 16.1.4. Brake and Steering System…………………………………………………………………………………………………………50 16.1.4.1. Braking Control System…………………………………………………………………………..……………………50 16.1.4.2. Steering System……………………………………………………………………………………………………………51 16.1.4.3. Tire, Brake and Landing Gear Monitoring Systems ………………………………………………………51
17. Powerplant…………………………………………………………………………………………………………………………………52
17.1. Rolls-Royce Trent 900……………………………………………………………………………………………………………………………..52 17.1.1. Equipment Tests…………………………………………………………………………………………………………………………54 17.1.2. Qualification Tests……………………………………………………………………………………………………………………..56 17.1.2.1. Bird Ingestion (FAR section 33.76)………………………………………………………………………………..56 17.1.2.2. Rain and Hail Ingestion (FAR section 33.78)………………………………………………………………….56 17.1.2.3. Vibration Test (FAR section 33.83)………………………………………………………………………………..57 17.1.2.4. Endurance Test (FAR section 33.87)……………………………………………………………………………..57 17.1.2.5. Engine Over Temperature Test (FAR section 33.88)………………………………………………………57 17.1.2.6. Blade Containment Rotor Unbalance Tests (FAR section 33.94)……………………………………58 17.2. Engine Alliance GP7200…………………………………………………………………………………………………………………………..59 17.2.1. Equipment Tests…………………………………………………………………………………………………………………………60 17.2.2. Qualification Tests………………………………………………………………………………………………………………………65 17.2.2.1. Bird Ingestion (FAR section 33.76)………………………………………………………………………………..65 17.2.2.2. Rain and Hail Ingestion (FAR section 33.78)………………………………………………………………….65 17.2.2.3. Vibration Test (FAR section 33.83)………………………………………………………………………………..66 17.2.2.4. Endurance Test (FAR section 33.87)………………………………………………………………………………66 17.2.2.5. Engine Over Temperature Test (FAR section 33.88)………………………………………………………66 17.2.2.6. Blade Containment Rotor Unbalance Tests (FAR section 33.94)……………………………..…….66
18. Hydraulic System………………………………………………………………………………………………………………………..67
18.1. Equipment Tests……………………………………………………………………………………………………………………………………..69 18.1.1. Eaton Corporation………………………………………………………………………………………………………………………69 18.1.1.1. Engine Driven Pump……………………………………………………………………………………………………..71 18.1.1.2. AC Motor Pump……………………………………………………………………………………………………………71 18.1.1.3. Fire Shut-Off Valve (FSOV)…………………………………………………………………………………………….72 18.1.2. Messier-Bugatti………………………………………………………………………………………………………………………….73 18.1.3.FR-HiTEMP……………………………………………………………………………………………………………………………………..74
19. Structural and Design………………………………………………………………………………………………………………….75
19.1. Ground Tests…………………………………………………………………………………………………………………………………………..75 19.1.1. Fatigue Tests………………………………………………………………………………………………………………………………75 19.1.2. Cabin Tests…………………………………………………………………………………………………………………………………77 19.1.3. Wing Tests………………………………………………………………………………………………………………………………….79
20. Flight Tests………………………………………………………………………………………………………………………………….82
20.1. MSN 001…………………………………………………………………………………………………………………………………………………83 20.2. MSN 002…………………………………………………………………………………………………………………………………………………83 20.3. MSN 004…………………………………………………………………………………………………………………………………………………84
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20.4. MSN 007…………………………………………………………………………………………………………………………………………………84 20.5. MSN 009…………………………………………………………………………………………………………………………………………………84 20.6. Crosswind Landing Flight Test…………………………………………………………………………………………………………………85 20.7. Natural Gas as a Fuel Alternative……………………………………………………………………………………………………………85 20.8. High Altitude and Hot Weather Testing…………………………………………………………………………………………………..85 20.9. Cold Weather Trails…………………………………………………………………………………………………………………………………86
21. Route Proving……………………………………………………………………………………………………………………………..87 22. Conclusion and Recommendations……………………………………………………………………………………………..89 23. Reference……………………………………………………………………………………………………………………………………90
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1. Introduction
Nowadays aerospace and aviation industries are expanding very quickly and rapidly to fill the gaps of consumers' needs, so as the industry expand, problems would also become big and bigger because of the high demand that would lead companies to increase their line of production and that obviously increase the percentage of errors and accidents in production due to lack of time but thanks to the aerospace and aviation organizations and authorities that set certain rules and regulation to minimize errors from happening even before the reaching the production line, It starts from the design of an aircraft as it is a synthesis of different disciplines like aerodynamics, flight mechanics, aeronautical structures, etc. Allowing as aircraft to be operational in normal air traffic, it is necessary to demonstrate that its design and construction are in compliance with the applicable requirements; the verification of such compliance is entrusted to the competent authorities. Airworthiness introduce aerospace engineers into a world consisting of one hand into the aircraft's designing, manufacturing and operation firms and on the other hand into airworthiness authorities, both hand should work together and they should aim at a common goal "Flight safety".
1.1. Flight Safety
Safety is a concept generally ingrained in the human mind; we will consider 'absence of danger' as its principal definition. Safety is something related to all human activities and therefore every civil society is organized (or should be organized) to guarantee public safety in relation to one's own or others' activities. This is certainly a moral obligation, but it is also a practical demand because accidents, causing damage to persons and properties, have a social cost. This is also the reason why human activities that could cause damage to persons and properties are controlled by national states through regulations. We will deal specifically with safety related to aeronautical activities, starting by considering what we have defined as the main conventional flight safety factors: man, the environment and the machine. 1. Man is intended here as an active part of the flight operations; we then consider pilots, maintenance manpower, air traffic controllers, and others. Clearly, it is important to be able to rely on very skilled people in order to avoid errors that cause accidents or catastrophes in flight operations. It is then of paramount importance to place these people in a legislative and organized context to guarantee a suitable level of professional training updating of techniques and procedures and psychological and physical fitness National states entrust special public institutions with the responsibility for such obligations.
2. The environment covers all the external factors that can have an influence on the flying of an aircraft. This includes meteorological conditions, traffic situations, communications, aerodromes, etc. It is equally important to avoid situations that could jeopardize the aircraft itself. Then we should consider correct meteorological information, rules for the vertical and
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horizontal separation of the aircraft, suitable aerodromes, etc. 3. The machine does not need a definition, but it is easy to understand the importance of a good project, sound construction, and efficiency in relation to the operations to be carried out. Also, in this case, national states entrust special public bodies with the responsibility of assuring that the project, the construction, and the operating instructions comply with flight safety. An important point regarding these safety factors is that they act in series and not in parallel. They can be seen as three links of a chain representing flight safety. The failure of a single link is sufficient for an accident to happen. A pilot's error can put the best aircraft in jeopardy, and the best pilot cannot compensate for a serious failure in an aircraft. Accident reports offer countless examples of this; however, accidents are often caused by a combination of factors that could involve all these safety factors. Nevertheless, the accident always begins with the failure of one of the above mentioned links.
1.2. Airworthiness
A definition of 'airworthiness' can be found in the Italian RAI-ENAC Technical Regulations: 'for an aircraft, or aircraft part, [airworthiness] is the possession of the necessary requirements for flying in safe conditions, within allowable limits.' In this definition, three key elements deserve special consideration: safe conditions, possession of the necessary requirements, and allowable limits. 1. We can take for granted the meaning of safe conditions relating to the normal course and satisfactory conclusion of the flight. According to one definition, safety is the freedom from those conditions that can cause death, injury or illness, damage to/loss of equipment or property, or damage to the environment.
2. Possession of the necessary requirements means that the aircraft, or any of its parts, is designed and built according to studied and tested criteria to fly in safe conditions, as mentioned above. Regulations are intended to promote safety by eliminating or mitigating conditions that can cause death, injury, or damage. Who establishes these regulations? The airworthiness authorities appointed by the national states. These are obtained through the publication of airworthiness standards containing a series of design requirements: from the strength of the structure to the flight requirements like flight qualities and performance, criteria for good design practice, systems, fatigue and flutter, necessary tests, flight and maintenance manual content, and so on. These standards are different for different types of aircraft. Obviously, it is not possible to design a sailplane, a 'Jumbo', or a helicopter using the same rules. An important peculiarity of these standards is their evolution as time passes. Generally, a standard does not precede aeronautical progress; it follows it and sometimes accompanies it. A 'blocked' standard would prevent aeronautical progress. It follows that the rules have to continuously fit with technical aeronautical evolution.
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Moreover, very often accident analysis leads to additional rules which, had they been applied to the design might have prevented the accident or at least limited its effects; this process could be regarded as 'afterthoughts', but it is better to consider it as 'experience'. The changing of the standards like normally with the purpose of adding something new or different would make the design compliance to the rules more and more expensive, but this is the price to pay to improve flight safety.
3. Allowable limits. Aircraft are designed for operation within a certain 'flight envelope', which depends mainly on speed and structural load factors. In addition, the maximum weight of the aircraft can be established differently for different types of operations. Operational conditions of the aircraft, such as day-VFR, night flight, instrumental flight, in or out of icing conditions, etc., are also established. Exceeding these conditions and limits can cause accidents. Overweight take-off, aerobatic maneuvers performed with aircraft designed with load factors for nonaerobatic operations, flights in icing conditions without suitable protection, and exceeding the speed limits are just few examples of the importance of flying within the allowable limits. Pilots are made aware of these limits through the flight manual, through the markings and placards displayed in the cockpit, and of course through training.
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2. Airworthiness Organization and Authorities
The aerospace and aviation industry is controlled by rules and regulation to restrict firms from designing or manufacturing parts that would lead to disasters, there are different of organization and authorities that set these rules and every organization has a different task but all meet at one approach is Airworthiness of aircrafts and part. Here is a list of some airworthiness organization and authorities and their task:
2.1. ICAO (International Civil Aviation Organization)
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The aims and objective of the ICAO are to develop the principle and techniques of international air navigation and to foster the planning and development of international air transport.
2.2. CAA (Civil Aviation Authorities)
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It's an airworthiness authority that has four tasks:
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Prescribe airworthiness requirements and procedures. Inform the interested parties regarding airworthiness prescription. Control aeronautical material, design, manufacturing organizations, and aircraft operators. Certificate aeronautical materials and organization.
2.3. JAA (Joint Aviation Authorities)
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The aim is to develop a harmonized airworthiness standards to meet the needs of the industry in Europe, particularly for products manufactured by international consortia, also to operations, maintenance, and licensing and certification design standards for all classes of aircraft.
2.4. The EASA (European Aviation Safety Agency)
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The aim of this agency is to assist European commission in preparing legislation, and support the member states and industry in putting the legislation into effect also to monitor the application of European community legislation. It also adopts its own certification specification and guidance material, conducts technical inspections, and issue certification where centralized action is more efficient.
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2.5. The FAA (Federal Aviation Administration)
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The FAA is responsible for the safety of civil aviation. Its main roles include:
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Regulating civil aviation to promote safety. Encouraging and developing civil aeronautics, including new aviation technology. Developing and operating a system of air traffic control and navigation for both civil and military aircraft. Researching and developing the national airspace system and civil aeronautics. Developing and carrying out programs to control aircraft noise and other environmental effects of civil aviation. Regulating US commercial transportation.
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3. Literature Review
3.1. Review
The A380 is the leader of aircrafts in 21st century, which falls into this category of very large aircraft; it can carry up to 800 passengers and has a maximum take-off weight (MTOW) of about 560 tons. A380 is not only the largest civilian aircraft ever, but is also more a combination of advanced technology in all aspects of aircraft engineering. With advanced technology that will make a step forward in the economics of operating, must also be an opportunity to be taken to ensure that this technology works the same for maintenance purposes. It is clear that the availability of aircraft, in terms of operational reliability, maintenance down time and maintenance cost are critical factors in the success of this particular aircraft, and therefore taken into account at the same level as the more traditional design objectives. The main objective of the maintenance is to clear and maintain the highest levels of airworthiness, but this does not conflict with the requirement to achieve very high availability of aircraft in operation costs to a minimum. The main goal of reliability of the A380 is much higher than the target was on the Airbus A340 series, which is 99% within two years of entry into service. It is clear that when a very large aircraft (VLA) such as the A380 gets bigger and longer-term and get, is more difficult to meet the airworthiness requirements set by authorities. Therefore, the FAA and EASA standards and requirements are placed on top of the list of priorities in the design of A380. Airworthiness requirements must be consistent with the objectives of maintenance, costs and the policy challenge is to put targets on the A380 equipment suppliers, especially for items that are undergo testing. Airworthiness is required from systems and component to test reliability because obviously critical factors in the early achievement of aircraft maturity and maturity assurance is planned through the design ‘Validation and verification’ (V&V) process and the introduction of intensive accelerated reliability testing to ‘shake out the bugs’ early enough so they can be fixed before entry into service. Aircraft level safety process was implemented for the first time on a large-scale commercial aircraft. It identifies aircraft level functions and associated failure conditions, decomposes them to multiple systems and places requirements on various levels of suppliers in the development of system and equipment. It has been shown that the outcome of the V&V process is the important basis on which all the critical engineering decisions to be made. In order to certify A380, Airbus’s engineers, working with the European Aviation Safety Agency and the FAA, reviewing any structural failure and determined what engineering changes must be made to the structure before the design can be certified. This paper presents the basic knowledge and methodology of V&V process including the objectives and framework. The implementation of V&V method in A380 safety process is discussed with the details of various analyses relating to this process. Lastly, this paper shows the example of how engine alliance applied V&V methodology in designing the GP7200 engine for A380 aircraft.
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4. A380 Concept Model History
4.1. Concept Model
The first A380 concept model was named A3XX with 49% more floor space than a jumbo jet but it had one huge problem in delivery of A3XX giant parts with Airbus Super Transporter (Beluga), in fact the A3XX was so massive that fuselage parts couldn’t be carried or fitted on the Beluga (Airbus largest cargo aircraft) which made Airbus reconsider their project plan for next generation super passenger carrier A3XX and look deeply to modify the shape to look into something completely different.
Part Fuselage Floor Beams Tail Section Wings Tail Fin Landing Gear Production Country Hamburg– Germany Tokyo–Japan Madrid–Spain Wales– United Kingdom Hamburg– Germany Toronto– Canada
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Airbus team ever studied currying A3XX wing biggie back style on other plane but after wind tunnel testing they decided the aerodynamics is too risky. Airbus head of transportation looked at ways to help rebirth the A3XX and came with a divided assistant system to transport aircraft parts by roads, rivers, and sea in a logistical dance that has to fit to together perfectly and work for first time. The fuselage, wing and tail planes will set off by sea by factories in Germany, Wales, France and Spain, converging on port of Bouc on the west coast of France where from there they will be loaded into barges that will carry them 59 miles to the river Dordogne and still the journey is not complete, a fleet of lorry will hold the parts by road to last 150 miles to Toulouse, this long process is under the supervision of Airbus’s Head of logistics where he has to coordinate the schedule.
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5. Airbus A380
5.1. A380
The project of making the world largest aircraft eclipsing Boeing's 747 was established by Airbus Company which is the competitor of Boeing Company. Airbus first began to study a very large 500 seats aircraft in the early 1990s. The success of Boeing 747 was the inspiration that made Airbus Company developed this aircraft as a strategy to collapse Boeing's dominance of the very large airliner market. In June 1994, engineering designer began their work on the A3xx. At that time, Airbus Company extremely interested to a single deck aircraft which would have 12 abreast and twin vertical tails. Nevertheless, Airbus decided to choose a twin deck configuration due to the requirement of lighter aircraft structure. There are 3 main proposes to design Airbus A380 which are that the ability to use existing airport infrastructure with little modifications to the airports, direct operating costs per seat 15-20% less than those for the B747 including provide more floor space, and lastly, Airbus prefers to make wider seats and aisles for the comfortable of passengers. Moreover, the most latest and advanced technologies are used in this aircraft considering lower fuel burn and emissions, and noise reduction. The 555 seats, double deck Airbus A380 entered service in March 2006. There are several models of A380. The basic aircraft is the 555 seats A380-800 and high gross weight A380-800, with the longer range A380-800R. The A380-800F freighter will be able to carry a 150 tones payload which dues to enter service in 2008. The A380700 is the future model with shortened 480 seats and the stretched 656 seats A380-900. Customer Air France Air Austral British Airways China Southern Emirates Etihad Airways ILFC Kingfisher Airlines Korean Air Lufthansa Malaysia Airlines Qantas Qatar Airways Singapore Airlines Thai Airways International Virgin Atlantic Prince Al-Walid A380-800 12 2 12 5 90 10 10 5 10 15 6 20 5 19 6 6 1 234
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Total Although A380 is not enter fully service, there are many airlines order the most ambitious civil aircraft. The following table shows the number of aircraft which each airline orders A380. (1)
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5.1.1. Aircraft Dimensions
Overall length Height Fuselage diameter Maximum cabin width
Metric 73 m. 24.1 m. 7.14 m. Main deck: 6.58 m. Upper deck: 5.92 m. 49.90 m. 79.8 m. 845 m2 33.5 degrees 30.4 m. 14.3 m.
Imperial 239 ft. 3 in. 79 ft. 7 in. 23 ft. 5 in. Main deck: 21 ft. 7 in. Upper deck: 19 ft. 5 in. 163 ft. 8 in. 261 ft. 8 in. 9,100 ft2 33.5 degrees 99 ft. 8 in. 46 ft. 11 in.
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Cabin length Wingspan (geometric) Wing area (reference) Wing sweep (25% chord) Wheel base Wheel track 5.1.2.
Basic Operating Data
Metric Engines Engine thrust range Typical passenger seating Range (w/max. passengers) Max. operating Mach number (Mmo) Bulk hold volume - Standard/option 5.1.3. Design Weights Trent 900 or GP 7000 311 kN 525 15.200 km. 0.89 Mo. 17.3 cu. m.
Imperial Trent 900 or GP 7000 70,000 lb. slst 525 8,200 nm. 0.89 Mo. 650 ft3
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Maximum ramp weight Maximum takeoff weight Maximum landing weight Maximum zero fuel weight Maximum fuel capacity Typical operating weight empty Typical volumetric payload
Ton 562 560 386 361 310.000 Liters 276.8 66.4
lb x 1000 1,239 1,235 851 796 81,890 US gal. 608.4 145.5
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5.2. Landing gear System
There are four main companies which develop the landing gear of A380 which are Goodrich, Messier-Dowty, Messier-Bugatti, and Smiths Aerospace. Each of company will develop in different part of landing gear. Firstly, Goodrich Company landing gear consists of two under wing struts each with four wheels, two central under- fuselage struts each with six wheels and a twin nose wheel. Next, Messier-Bugatti takes care about the brake and steering system of landing gear of A380. Thirdly, nose landing gear is supplied by Messier-Dowty Company with 350 bar hydraulic pressure. For landing gear extension and retraction system are supplied by Smiths Aerospace Company. The characteristic of landing gear of A380 is approximately 18 and half feet tall and a single A380 body landing gear supports about 167 tons which can hold up 2 and half Airbus A320 aircraft
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including passengers and their luggage. The main landing gear is manufactured in Canada. The major test facility is a Super Rig for structural testing which includes the strength and fatigue testing of both wing and body landing gears of A380. Good rich Company stated that "an endurance test rigs are being added to accommodate the retraction endurance test and the steering endurance testing of the body landing gear bogie beam. The drop testing of the landing gear will be performed on-site in a separate building". Moreover, the tests are conducted as in real flight operation for evaluating and analyze the most accurate response of landing gears. (2)
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5.3. Brake and Steering System
For brake and steering system, normally, in the large aircraft have three sets of redundant hydraulics which are two primary circuits and a third back-up for safety, all adding up to a big load of hefty piping. The way to reduce this mass is to replace with a decentralized fluid-power generation system on the A380. The micro which uses in A3 80 provides 5,000 psi (350 bars) of local hydraulic pressure over short runs of small-diameter light weight piping for braking and steering. There are so many challenges in optimizing system performance such as integrating and sizing the large number of different physical parts, and electrical and hydraulic systems. The solution for these challenges is to use the LMS Imagine Lab Ground Loads solution, so this solution allows engineers to investigate
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parameters and scenarios. With these capabilities, the company can simulate the behavior of the electro-hydraulic system for the A380. Moreover, the A3 80 can enter into service with this nose wheel steering system control loop only tuned with LMS Imagine Lab. (3)
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The Body Wheel Steering (BWS) is powered by the yellow hydraulic circuit. The system and controls the rear axle of the Body Landing Gear.
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A380 Landing Gear showing all wheels and brake status
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5.4. Structural Design
For many years, aircraft designers may establish many aircrafts in theoretical but they always say that they cannot become real in practice because the material which use to build the aircraft structure does not exist or cannot find. However, nowadays, composite material plays as an important role to build aircraft structure. Composites are the most significant materials that are adapted to use in aviation industry since the use of aluminum in the 1920s. The process of making composite structures is more complex than making metal structures. One useful feature of composites is that they can be layered, with the fibers in each layer running in a different direction. This can lead to aircraft designers design structures that behave in certain ways. Moreover, there are several advantages that can gain from composite material. The greatest value of composite materials is that they provide lightweight structure and strong at the same time. The lighter aircraft weighs, the less fuel consumptions, so reducing weight is the most important thing that aerospace engineers must concern. Moreover, composite material does not provide only reduction of weight but also gives an advantage in aerodynamic performance of the aircraft. Additionally, Airbus Company stated that "lower airframe weight and better aerodynamic contributed to the decrease of demands placed on engines and translate into lower fuel burn and lower operating costs". Due to composite material have many advantages when weigh to disadvantages, Airbus Company decide to choose composite material in A380 structure. Twenty-five percents of the structure of A380 made up by composites material. The rest of A380 structure made by aluminum, miscellaneous, surface protections, and titanium and steel accounting for sixty-one percents, two percents, two percents, and ten percents respectively. In twenty- five percents of the whole structure of A380 structure is composite material, can be classified into two main types which are Carbon Fiber Reinforced Plastic (CFRP) and GLARE. (4)
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5.5. Powerplant
The Airbus A380 has novel of unusual design features when compare to the current state of technology and also A380 is the biggest commercial aircraft that ever have before. There are several issues that Airbus Company and his partners need to concern. The powerplant is one of the significant issues that these companies cannot ignore. Due to the fact that A380 has a maximum takeoff weight of approximately 560 tons as shown in the A380-specifications section. Hence, the powerplant that will be used in this aircraft must have the high driving power. Rolls-Royce and General Electric Aviation and Pratt & Whitney will develop the powerplant for A380. There are two models of engine selected as the powerplant systems of the super-jumbo aircraft A380 which are:
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GP 7200 Trent 900
(5)
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6. A380 Tests and Certification
6.1. Overview
Federal Aviation Administration and European Aviation Safety Agency are so strict in their policy to certify and validate a new design aircraft, therefore airbus were required to do all type of testing on their new design aircraft to secure their business and ensure customers and FAA would be happy, so in order to certify Airbus A380, it was required to run several tests on the actual aircraft after passing all computational tests. It took airbus a long time to verify testing and ensure everything was going in the right track, due to long time testing took, it was delayed on delivery to customers. A380 attempted too many tests in different parts on world, some of these tests are: ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· ï‚· Velocity Minimum Un-stick Test Rejected Take-off Test Flutter Tests High Altitude Test Cold Weather Test Hot Weather Test Evacuations Tests Velocity Minimum Control Ground Tests Technical Route Proving Crosswind Landing Test Wing Fuselage Testing Blade Off Engine Test Landing Gear Test Brake test (Overload Landing)
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7. A380 Type Certificate
7.1. Obtaining Type Certificate
The type certificate is a document by which the authority states that an applicant has demonstrated compliance of type design to all applicable requirements. This certificate is not in itself an authorization for the operation of an aircraft, which must be given by an airworthiness certificate. Obtaining type certificate is the first step of the new aircraft being successful as it meets the drawing, specification, methods of manufacturing and other data requirements. (6)
7.2. A380 Type Certificate
The European Aviation Safety Agency (EASA) issued its safety approval for the Airbus A380. The A380 is the first large European aircraft to be certified by EASA. The EASA “type-certificate” confirms that the design of the aircraft complies with European safety and environmental standards. The A380 can now be legally registered and operated commercially throughout the European Union. In addition, the type-certificate is valid in Switzerland, Norway, Iceland and Liechtenstein. At the same time, the Federal Aviation Administration (FAA) has issued its “validation” of the A380 certification for the US market. The certification process for the A380 began in 1998 with the French aviation authority and was taken over by the Agency when it started operations in 2003. A team of 42 certification specialists headed by the Agency have scrutinized the aircraft’s design involving hundreds of demonstrations and flight-tests. A major test involved 853 passengers plus crew being evacuated from the aircraft in 78 seconds, well below the required pass mark of 90 seconds. (7) The A380 certification is the first to be jointly completed by the European Aviation Safety Agency (EASA) and the U.S. Federal Aviation Administration (FAA).
7.3. A380 Preparation testing for Type Certificate
The A380 test program started with systems testing in 2001, structural testing in November 2004 and structural fatigue testing in September 2005. This then led to one of the most extensive certification flight test programs in the history of Airbus, marked with the first flight on 27th April 2005 and ending on 30th November 2006 with the successful around the globe technical routeproving trip, which took the aircraft over both poles, testing the aircraft’s performance under normal airline operations. The flight tests have been designed to assess the general handling qualities of the aircraft, operational performance, and airfield noise as well as systems operation, in normal mode, failure cases and extreme conditions. For the extreme weather trials Airbus has taken the aircraft from the cold of Northern Canada, to the desert heat of the Gulf and hot and high altitudes of Ethiopia & Colombia where it yielded excellent results and in many cases surpassed its design targets. (7)
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Further flight tests for certification purposes have been dedicated to water ingestion trials; low speed take-off tests; flutter; and rejected take off and landings. In addition to a number of wake vortex trials required for certification, Airbus has performed and continues to perform a large series of tests and measurements in this area. These tests have been designed to gather data to support recommendations by the A380 Wake Vortex Steering Group made to the International Civil Aviation Organization (ICAO), regarding safe wake vortex separation criteria for aircraft following an A380 for various flight conditions. In addition to flight test success, further highlights have included airport compatibility trials with a total of 38 airports visited to date around the globe during which the ability to operate the A380 in the same way as existing large aircraft has been demonstrated. The A380 cabin also underwent a series of tests for certification, including the successful evacuation test, performed at Airbus' Hamburg site, Germany, on 26th March 2006. During this largest ever aircraft evacuation trial 853 passengers and 20 crew members left the aircraft within 78 seconds 12 seconds less than required, validating 853 as the maximum passenger seating capacity, for the A380-800. Although not required for certification, but part of Airbus' commitment to smooth entry into service, Airbus undertook a series of four Early Long Flights in September 2006 where over 2000 Airbus employees took part to assess the cabin environment and systems in flight. These followed a 15 hour Virtual Long Flight, that took place in May 2006 in Hamburg, where 474 Airbus employees tested cabin systems in simulated long haul conditions. (7)
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8. Federal Aviation Administration (FAA)
8.1. Background
Federal Aviation Administration (FAA) is an agency of the U.S. Department of Transportation with the authority to regulate and oversee all aspects of civil aviation. The establishment of the Federal Aviation Act of 1958, a group under the name "Federal Aviation Agency", and adopted its current name in 1967 when it became part of the United States Department of Transportation. There are numerous regulations from the FAA, which was established to address the issues of safety and reliability of each aircraft. Designer who want to create new aircraft or to adapt an old aircraft to be new in market, must be concerned about Federal Aviation Administration regulation, because if the aircraft does not meet the organization, then it must be that this aircraft has not received a certificate from the Federal Aviation Administration, and as a result, the aircraft with the lack of qualified work. Designers and engineers should be aware of regulation and standards in the selection of systems, as mentioned in FAA and the bottom line of security and reliability issue. The following pages summarize all the important ones that affect: 1. 2. 3. 4. 5. Landing gear Structural design Engine Hydraulic system Special conditions (Special design standards of an unusual aircraft like A380)
The FAA is responsible for the safety of civil aviation. Its main roles include: 1. Regulating civil aviation to promote safety. 2. Encouraging and developing civil aeronautics, including new aviation technology. 3. Developing and operating a system of air traffic control and navigation for both civil and military aircraft. 4. Researching and developing the national airspace system and civil aeronautics. 5. Developing and carrying out programs to control aircraft noise and other environmental effects of civil aviation. 6. Regulating US commercial transportation.
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9. Federal Aviation Administration (FAR 25: Landing gear)
9.1. FAR section 25.721 - General
The system of the main landing gear must be designed in a way if the landing gear fail or collapse during takeoff and landing according to the load that applied to the landing gear is more than the maximum load of landing gear can hold, the failure mode is not likely to cause the spillage of enough fuel from any part of the fuel system to delegate a fire hazard. The aircraft that has passenger more than ten seats excluding pilot seats must be designed with the condition that if the aircraft is in under control, the aircraft can be landed on a paved runway without a structural component failure. (8)
9.2. FAR section 25.723 - Shock absorption tests
The energy absorption tests at limit design conditions must include at least the design landing weight or the design takeoff weight. Moreover, the test attitude of the landing gear unit and the application of appropriate drag loads during the test must simulate the airplane landing conditions. The landing gear may not fail in a test, demonstrating its reserve energy absorption capacity, simulating a descent velocity at design landing weight. (9)
9.3. FAR section 25.731 - Wheels
The main and nose wheel must be approved and the maximum static load rating of each wheel may not be less than the corresponding static ground reaction with the design maximum weight and critical center of gravity. The maximum limit load rating of each wheel must equal or exceed the maximum radial limit load determined under the applicable ground load requirements of this part. The overpressure burst must be prevented from excessive pressurization of the wheel and tire. (10)
9.4. FAR section 25.733 - Tires
The tires that are chosen must fit appropriate to the wheel with a speed rating approved by the Administrator which is not overdo under critical conditions and with a load rating must not exceed under the loads on the main wheel tire, the loads corresponding to the ground reactions. The tires that are installed to the retractable landing gear must have the clearance to surrounding structure and systems which is enough to prevent unpredictable damage between the tire and other part of aircraft structure. For the airplane that has the maximum takeoff weight more than 75,000 pounds, the tires mounted on braked wheels must be inflated with dry nitrogen or other gases. (11)
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9.5. FAR section 25.735 - Brakes and braking systems
The brake system must have capability to bring the airplane to the rest with a braked roll stopping distance of not more than two times when any single source of hydraulic or other brake energy supply is lost. The parking brake control of airplane must be selected on for preventing rolling on a dry of the airplane. Moreover, this control must have capability enough to prevent inadvertent operation. For kinetic energy capacity, when design landing stop, it must use the dynamometer for testing that the wheel, brake and tire have capability of absorbing the kinetic energy in the accepted level or not. The mean deceleration must not be less than 10 fps². (12)
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9.6. FAR section 25.737 - Skis
The 14 CFR parts 25 section 737 states "Each ski must be approved. The maximum limit load rating of each ski must equal or exceed the maximum limit load determined under the applicable ground load requirements of this part".
9.7. FAR section 25.487 - Rebounding landing condition
In this section, it’s divided into two main parts. 1. Landing gear structure must qualify the aircraft loads that will occur during rebound. 2. If the landing gear is fully extended without contact with the runway, a load factor of 20.0 must operate on the unapplied weights in the direction of motion of the unapplied weights. (13)
9.8. FAR section 25.1515 - Landing gear speeds
The operating speed, VLO, must not more than the safety level in both to extend and to retract the landing gear. In case of extension speed, the speed VLE must definitely not exceed the speed when the aircraft fly with fully extended landing gear. (14)
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9.9. FAR section 23.729 - Landing gear extension and retraction system
For an airplane with retractable landing gear must be designed for maximum flight load factors with the gear retracted and must be designed for the combination of friction, inertia, brake torque, and air loads, occurring during retraction at any airspeed up to 1.6 VS1 with flaps retracted. For an emergency case, if aircraft cannot be able extended manually, there must be able to extend the landing gear in the normal landing gear operation system or in a power source that prevent the operation of the normal landing gear operation system. In every aircrafts, the landing gear warning devices need to be installed. For landing approach, if the landing gear is not fully extended and locked, the warning system must be designed for this situation. Another circumstance that must be concerned is that when the wing flaps are extended over the maximum flap position, the warning system for this device may use any part of the system including aural warning device. (15)
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10.Federal Aviation Administration (FAR 25: Structural and Design)
10.1. FAR section 25.303 - Factor of safety
A factor of safety of 1.5 must be applied to the limit load which are concerned external loads on the structure and when a loading condition is dictated in terms of ultimate loads, a factor of safety do not need to be applied. (16)
10.2.
FAR section 25.307 - Proof of structure
The structure must be in an acceptable level in the issues of strength and deformation requirement for each critical loading condition. The ultimate load tests need to be done when the limit load tests are not sufficient. Before choosing material, the administrator need to test the material correction factors that appropriate to the structure or not. (17)
10.3.
FAR section 25.341 – Gust and turbulence loads
In the issue of discrete gust design criteria, the vertical and lateral gusts need to be symmetrical in level flight. Loads on each part of the structure must be determined by dynamic analysis. The analysis must take into account unsteady aerodynamic characteristics and all significant structural degrees of freedom including rigid body motions.
10.4.
FAR section 25.523 - Design weights and center of gravity positions
For design weights, the water load requirements must be met at each operating weight up to the design landing weight except, the design water takeoff weight must be used. For center of gravity positions, the critical centers of gravity within the limits for which certification is requested must be considered to reach maximum design loads for each part of the seaplane structure. (18)
10.5.
FAR section 25.603 - Materials
The suitable materials that will use for many parts of structure must pass the basis of experience or tests and these materials need to be approved by the industry or military specifications or Technical Standard Orders to ensure that these materials have the strength and other properties enough to use. Moreover, if all of above are satisfied, the environmental issues are needed to be accounted for example temperature, and humidity. (19)
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10.6.
FAR section 25.631 - Bird strike damage
The main detail for this section is that "The empennage structure must be designed to assure capability of continued safe flight and landing of the airplane after impact with an 8-pound bird when the velocity of the airplane (relative to the bird along the airplane's flight path) is equal to VC at sea level, selected under §25.335(a). Compliance with this section by provision of redundant structure and protected location of control system elements or protective devices such as splitter plates or energy absorbing material is acceptable. Where compliance is shown by analysis, tests, or both, use of data on airplanes having similar structural design is acceptable."
10.7.
FAR section 25.681 - Limit load static tests
The limit load requirement for this section must test the direction of the test loads produces the most severe loading in the control system including fitting, pulley and bracket used in attaching to the main structure. (20)
10.8.
FAR section 25.843 - Tests for pressurized cabins
The main idea from this section is that "Flight tests, to show the performance of the pressure supply, pressure and flow regulators, indicators, and warning signals, in steady and stepped climbs and descents at rates corresponding to the maximum attainable within the operating limitations of the airplane, up to the maximum altitude for which certification is requested. " In addition, the tests of the pressurization system to show proper function under each possible condition of pressure, temperature, and moisture, up to maximum altitude for which certification is requested.
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11.Powerplant
11.1. FAR section 25.903 - Engines
The powerplants must be installed separate to each other for preventing failure of any engine or any system that can affect the engine. The airplane that uses the turbine engine must have the precaution for minimizing the dangerous in case of an engine rotor failure. Moreover, the engine control devices, systems, and instrumentation must be designed to provide sufficient assurance. The turbine engine powered airplanes must have capability to restart the engine by using a power source independent of the engine-driven electrical power generating system to allow in-flight engine ignition. (21)
11.2.
FAR section 25.939 - Turbine engine operating characteristics
Turbine engine operating characteristics must be examined to classify that no adverse stall, surge, or flameout to a risk degree during normal and emergency operation within the range of operating limitations of the airplane. (22)
11.3.
FAR section 25.963 - Fuel tanks: general
The materials that use to build the fuel tank must be able to resist without any failure modes. There are two main types of fuel tank which are flexible fuel tank and integral fuel tanks. Each of fuel tank must be approved and have the particular application. For the fuel tanks which near the fuselage must have the capability to resist rupture and retain fuel under the inertia forces for emergency landing. For the fuel tank access covers, all covers must have minimize penetration and deformation bye tire fragments, low energy engine debris and all cover must have the qualification to resist fire. (23)
11.4.
FAR section 25.1125 - Exhaust heat exchangers
Each exhaust heat exchanger must resist each vibration, inertia, and other load. Moreover it must be able to operate at high temperatures and resistant to corrosion from exhaust gases. The cooling provisions must have in each of exchanger. In case of exhaust heat exchanger is used for heating ventilating air, a secondary heat exchanger must be provide between the primary exhaust gas heat exchanger and the ventilating air system. (24)
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11.5.
FAR section 25.1141 - Power plant controls: general
Each control must be located on the place that cannot operate by people who entering or leaving in that area normally in cockpit. Each flexible must have the particular application and have sufficient strength and rigidity to withstand operating loads without any failure modes. (25)
11.6.
FAR section 25.1203 - Fire detector system
The numbers and locations detection of fire must be classified and each fire detector system must be constructed and this system must also withstand the vibration, inertial, and other loads. Any oil, water, and other fluids might not cause the effect to fire and overheat detector. Crew must have capability and allowable to check each fire or overheat detector during in flight. Fire or overheat detector must not go through other fire zone unless the zones are relevant to prevent by this detector. (26)
11.7.
FAR section 33.76 - Bird ingestion
The FAA regulation 14 CFR part 33 section 76 states "All ingestion tests shall be conducted with the engine stabilized at no less than 100-percent takeoff power or thrust, for test day ambient conditions prior to the ingestion. In addition, the demonstration of compliance must account for engine operation at sea level takeoff conditions on the hottest day that a minimum engine can achieve maximum rated takeoff thrust or power". Additionally, the test by using the large bird ingestion needs to be done by using a weight of bird from the table below. The aim of this test is to explore the most critical exposed location on the first stage of rotor blades.
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11.8.
FAR section 33.83 - Vibration test
The vibration qualification must be required by establishing the vibration surveys of each engine and this qualification must be in acceptable level throughout the flight envelope. These surveys also accumulate the ranges of power, thrust, and rotational speeds for each rotor system. The effects on vibration characteristics of excitation forces caused by fault conditions (such as, but not limited to, out-of balance, local blockage or enlargement of stator vane passages, fuel nozzle blockage, incorrectly schedule compressor variables, etc.) shall be evaluated by test or analysis, or by reference to previous experience and shall be shown not to create a hazardous condition. In addition, The FAA regulation 14 CFR part 33 section 83 says "Compliance with this section shall be substantiated for each specific installation configuration that can affect the vibration characteristics of the engine. If these vibration effects cannot be fully investigated during engine certification, the methods by which they can be evaluated and methods by which compliance can be shown shall be substantiated and defined in the installation instructions required by §33.5. "
11.9.
FAR section 33.88 - Engine over temperature test
The turbine must be in serviceable limits by following this method which is each engine must run for 5 minutes at maximum permissible rpm with the gas temperature at least 75°F or 42°C higher than the maximum rating's steady-state operating limit. (27)
11.10.
FAR section 33.94 - Blade containment and rotor unbalance tests
The engine need to be demonstrated in the test that this engine has enough capability to carry damage without any failure modes and catching fire when the test is being done at least for 15 seconds. According to the FAA regulation 14 CFR part 33 section 94 claims that failure of the most critical compressor or fan blade while operating at maximum permissible rpm. The blade failure must occur at the outermost retention groove or, for integrally-bladed rotor discs, at least 80 percent of the blade must fail.
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12.Hydraulic system
12.1. FAR section 25.1435 - Hydraulic System
Element Proof Ultimate (xDOP) (xDOP) 1.5 3.0
12.1.1. Element design
1. Tubes and fittings 2. Pressure vessels containing gas: High pressure (e.g., accumulators) 3.0 4.0 Low pressure (e.g., reservoirs) 2.0 3.0 3. Hoses 2.0 4.0 4. All other elements 1.5 2.0 Proof and Ultimate pressures in terms of the design operating pressure (DOP) Each element of a hydraulic system must stand and be resisted to:
1. The pressure without permanent deformation and the ultimate pressure without rupture. 2. Elements in a hydraulic system should withstand without deformation, the design operating pressure in combination with limit structural loads that may be imposed. 3. Elements must withstand without rupture when using a factor of 1.5 by multiplying (DOP) in combination with ultimate structural load. 4. Elements must withstand the fatigue effects of cyclic pressures. 12.1.2. System design The main issues that each hydraulic system must meet: 1. 2. 3. 4. Located at a flight crew station to indicate appropriate system parameters System pressures are within the design capabilities of each element Degraded the release of harmful of hydraulic fluid during flight Designed to use a suitable hydraulic fluid specified by the airplane manufacturer
12.1.3. Tests Each element related to a hydraulic system must be pass the tests before are set to service. Failure of an element at testing stage can occur, so elements error must be collected and retested. In the test, the significant issues that each element must be tested are ï‚· ï‚· ï‚· Performance Fatigue Endurance of airplane ground and during flight operations (28)
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12.2.
A380 Hydraulic System
Aircraft manufacturers are one of the most important industries, focusing mainly on the structure of the aircraft's weight. Every extra pound consumes more fuel and that means it will increase the cost risk. Airbus previous models were using a hydraulic system that would produce 3000 lbs / square inch, but Airbus invited a new system to support it late test model A380 which will make it completely different. Airbus A380 can carry up to 800 passengers on single class with an estimated travel distance of up to 8000 miles on full fuel tanks that means Airbus engineers need to think of a new compatible hydraulics system technology to be fitted on A380 to. Prior to Airbus decision, Engineer begun to communicate with hydraulic systems industry, where they initiated several hydraulic discussion aims about both advantages and disadvantages of the current systems used. In conclusion of discussion, a hydraulic system of 5000 lb / square inch of water was developed and to be used in A380. (29) Hypertension from 3000 to 5000 lbs / square inch benefited A380 program because it allows the same transmitted energy required to be delivered with a smaller pipes and hydraulic components, where it reduces the weight of the aircraft at about one metric ton. An A380 hydraulic system has been used by defense force on their high-pressure systems for years, and which has evolved to 5000 lbs / square inch and stood well to test rehabilitation. Experience has shown with the existing hydraulic fluids and components that the fluid does not degrade under greater pressure. Airbus engineers have chosen Eaton hydraulic system to provide 5000 lbs / square inch for hydraulic power generation in A380. There are several important issues that should be concerned carefully in the 5000 lbs / square inch, like: ï‚· Stress factors ï‚· Pulse pressure ï‚· Efficiency ï‚· Deflection pressure ï‚· Balances the pressure ï‚· Materials selection Eaton hydraulic system is made of: ï‚· ï‚· ï‚· Eight Vickers PV3 -300-31 hydraulic engine-driven pumps (EDPs) Four AC motor pumps (The largest ever designed to date for an aircraft) Electronic control and protection systems
(30)
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13.Special Conditions (FAR 25: Structural and Design)
13.1. Special Conditions: Airbus Model A380-800 Airplane, Crashworthiness
The size and configuration of Airbus A380 are the main subjects that make this special condition occur. According the FAA regulation 14 CFR part 25 sections 561 stated that the design load conditions must cover the emergency landings for the local structures in the passenger compartment. The structure of airplane must show the reasonable capability of the airframe in crash landings. However, the FAA hasn't got much enough information to confirm that the structure of Airbus A380 has capability to qualify the safety requirement. Hence, the FAA decides to offer the special condition which emphasizes to test and analyze the structure to satisfy a level of crash survivability equivalent to conventional large airplanes. The vertical loading of the fuselage is the only issue that will address in this special condition This special condition also has some doubts especially in case of safety and reliability issues so the FAA decides to establish a referenced point to compare the structure capability of A380 with the structure of current large aircraft. This reference point is namely as "Limit of Reasonable Survivability". The vertical descent rate is defined in this reference point by exceeding of physiological limits of the occupants. (31) FAA gives some recommendation about this special condition "Accommodating the changes requested by ALPA would be beyond the scope of this rulemaking. The purpose of the special condition is to assure that the large size and full length double deck configuration of the A380 design do not degrade the survivability characteristics of the A380 fuselage shell compared to designs for conventional large transport category airplanes. The purpose is not to create a higher safety standard for the A380."
13.2.
Special Conditions: Airbus Model A380-800 Airplane, Airplane Jacking Loads
This special condition is the supplementary condition for the FAA regulation 14 CFR part 25 sections 519. Due to Airbus A380 has a multi-leg landing gear configuration which is two wing mounted gear, nose gear, and two body mounted gear but this arrangement is not match to the FAA regulation which said that an arrangement of landing gear consisting of three point suspension system. As a consequence, this may not affect to share the load between landing gear if follow the FAA regulation but the Airbus A380 has five point suspension systems so the special condition needs to be established. In this case, calculation of loading sharing between landing gear units has to be done. A rotational analysis of the jacking condition for the main and body landing gear is permitted in this special condition including the case of bogie gears where on leg of a bogie is jacked and other leg is supported on a tripod. (32)
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13.3. Special Conditions: Airbus Model A380-800 Airplane, Transient Engine Failure Loads
With a very large high bypass ratio engines of A380 model which is 110 inch diameter bypass fans result in the larger size of the engine which normally be the cause of higher inertia of the rotating components. This was not envisioned with Sec. 25.361 (pertaining to loads imposed by engine seizure) which was adopted in 1965; for that reason, there are two other sections that need to be referred: Section 25.361(b) (1) requires that for turbine engine installations, the engine mounts and the supporting structures must be designed to endure a “limit engine torque load imposed by sudden engine stoppage due to malfunction or structural failure." Limit loads are expected to occur about once in the lifetime of any airplane. Section 25.305 requires that supporting structures be able to support limit loads without detrimental permanent deformation, meaning that the supporting structures From the adoption of Sec. 25.361(b) (1), the size, configuration, and failure modes of jet engines have altered considerably. Currently, many engines are much larger and designed with large bypass fans. In the event of a structural failure, these engines are capable of producing much higher transient loads on the engine mounts and supporting structures. As a consequence, the modern high bypass engines are exposed to the certain rare-but-severe engine seizure events. Owing to the service history, it shows that these events occur far less frequently than limit load events. Even though it is essential for the airplane to be able to support such rare loads safely without failure, and it is impossible to expect that no permanent deformation will occur. From the above situation, a design standard for today's large engines has been proposed by Aviation Rulemaking Advisory Committee (ARAC). For the commonly-occurring deceleration events, the engine mounts and structures are required to support maximum torques without detrimental permanent deformation as the proposed standard. For the rare-but-severe engine seizure events (i.e., loss of any fan, compressor, or turbine blade), the engine mounts and structures to support maximum torques without failure are needed for proposed standard, but allows for some deformation in the structure. In conclusion, the FAA considers that modern large engines, including those on the Model A380, are novel and unusual compared to those envisioned when Sec. 25.361(b) (1) was applied and thus warrant special conditions. Besides the special conditions also includes design criteria, as recommended by the ARAC. For the ARAC proposal, it needed to be revised in the wording of Sec. 25.361(b), including Sec. 25.361(b)(1) and (b)(2), removing the language pertaining to structural failures and moving it to a separate requirement which discusses the reduced factors of safety that apply to these failures. The revised wording of Sec. 25.361(b) would also include non-substantive changes recommended by ARAC to clarify the existing requirement. Moreover, the FAA is employing this ARAC text in these special conditions, because it clarifies the supplementary conditions for engine torque. (33)
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13.4. Special Conditions: Airbus Model A380-800 Airplane, Reinforced Flight deck Bulkhead
The unusual design features bring to Airbus A380 has so many special conditions. In this special conditions will generate the flight deck bulkhead of A380. According to the FAA regulation 14 CFR part 25 section 795 states that the installation of flight deck door must be designed to oppose the unauthorized persons by any efforts. This regulation has a limit only the flight deck door but for the Airbus A380, the flight deck bulkhead needs to be classified. The FAA is now making the amendment of this regulation section, whereas, the special condition is established. This special condition requires that the door of the flight deck bulkhead use the same standard and meet the requirement in 14 CFR part 25 sections 795. (34)
13.5.
Special Conditions: Airbus Model A380-800 Airplane; Fire Protection
This special condition is the additional information of 14 CFR part 25 sections 857. The full-length double deck passenger cabin and electrical equipment bays are the direct effects to this special condition. The current regulation of FAA 14 CFR part 25 sections 857 said that cargo compartments have a means to separate the dangerous of smoke to the occupied area of the airplane. However, this regulation does not cover the dangerous of smoke from one deck to another deck or between two decks via a connection stairway. Moreover, the current FAA regulation does not state about the detection of smoke in an electrical equipment bay. Usually, the electrical equipment bay located under the flight deck but for Airbus A380, it might bring to the risk of smoke which may affect to passengers and crew. (35) The FAA establishes this special condition for covering the lack of issues.
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14.Special Conditions (FAR 25: Landing Gear)
14.1. Special Conditions: Airbus Model A380-800 Airplane; Loading Conditions for Multi-Leg Landing Gear
This special condition is quite similar to the airplane jacking loads special condition that discuss in the structural and design section. For this special condition will focus mainly on the landing with load condition suitable for multi-leg landing gear of A380. (36) The ARAC working group proposes this special condition gathering various landing gear configurations. According to the ARAC working group, this notice can classified into two groups of special conditions. (Group A) addresses landing conditions as the following: A.1. Landing load conditions and assumptions A.2. Symmetric landing load conditions A.3. One-gear landing conditions A.4. Side load conditions (Group B) addresses other conditions and tests including Ground Handling Conditions as the following: B.1. Ground handling conditions B.2. Taxi, takeoff and landing roll B.3. Braked roll conditions B.4. Nose-wheel yaw and steering B.5. Pivoting B.6. Reversed braking B.7. Ground load: unsymmetrical loads on multiple-wheel units B.8. Shock absorption tests
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14.2.
Special Conditions: Airbus Model A380-800 Airplane, Ground Turning Loads
This special condition is the supplementary information of the FAA regulation 14 CFR part 25 sections 495. According to the FAA regulation 14 CFR part 25 section 495 stated that the current or conventional aircrafts which are the lateral loads experienced by the bigger aircrafts during ground turns are less than the smaller aircrafts do. Meanwhile, the Airbus A380 is heavier than others more than approximately 30% so Airbus A380 cannot use the 0.5 g design turning load factor which is claimed in the FAA regulation 14 CFR part 25 sections 495. Hence, the new design turning load factor which is suitable to the size of A380 is 0.45. (37)
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15.Verification and Validation Process (V & V)
Verification and Validation is a model that helps system designers and test engineers in confirming that a product being built correctly throughout the development process to improve software product quality. (38)
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Verification and Validation process confirm that certain rules are followed correctly in the process of software product development, also confirms that a product is developed to fulfill the required specifications. V&V reduces any associated project risk to certain level by helping in early detection and correction of errors, which are usually built without a notice during development process. (38)
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15.1.
Verification
Design verification aims to provide evidence that the design meets the requirements, this line of evidence presented through the analysis of the project, and a major contribution to make a decision on the selection of the design decisions and to begin the next phase of development, or in other words is to know if we building the right product or not. (38) Methods and techniques used in the verification process must be designed carefully. There are three main methods used in verification: inspection, walkthroughs and buddy checks. Inspection: Inspection includes a group of 3-6 people, led by the leader, who formally review the documents and work product in various stages of the life cycle of product development. Work product and related documents submitted to the inspection team, which leads to different interpretations of the presentation. Errors discovered during the inspection are sent to the next level with care. Walkthroughs: Can be seen wandering the same examination without formal training (i.e., view or document). During the passage of the main meeting / Authors submit articles to all the participants in order to make them familiar with it. Even walkthroughs can help identify potential errors, but it’s mainly used for a knowledge exchange and communications objectives. Buddy Checks: This is the easiest type of review activities, which were used to identify errors in the product during verification. Buddy checks sets one person to go through the documents prepared by someone else in order to ensure that the person committed no error (s), i.e. errors discovery that author cannot find before. In addition, there are two main ways where the basic techniques are used widely in a large company. Main methods for testing are dynamic and static testing. (38) Dynamic testing: In principle, is to choose a number of tests cases where each test case consists of test data. The input test cases are used to determine the test results yield. Dynamic test can be divided into three categories - functional testing, structural testing and random testing. Functional testing: Involves identifying and testing all the functions of the system, as defined within the requirements. This type of testing is an example of black box testing because it doesn’t require you to know about the implementation of this system. (39) Structural testing: It’s a complete knowledge on the implementation of the system and an example of white box testing. It uses the information from the internal structure of test development to test individual components. Functional and structural testing chooses test cases that investigate a particular characteristic of the system.
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Random testing: Choosing freely test cases from a range of test cases for all possible tests. It determines by the use of random inputs that can detect errors which are detected by other means of testing methodology. Exhaustive testing, where the input test cases consists of every possible set of input values, is a form of random testing. Although exhaustive testing is comprehensive in each stage of the life cycle results in a full system scan, it is really impossible to meet. Stating testing: Not associated with the system or component operation where some of these methods of manually, and other automated. Static testing can be divided into two techniques categories - techniques that analyze consistency and techniques that measure some program property. Consistency techniques: Used to ensure that the properties of a program such as the correct syntax, the correct parameter matching between the procedures printed correctly, and correct translation of the requirements and specifications. Measurement techniques: Measure properties such as the errors tendency, clarity, and wellorganized. (39)
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15.2.
Validation
Validation is to ensure that the requirements of a product are correct and complete enough to ensure the safety and customer satisfaction within the limits of the program. All types of testing methods are carried in the verification process. Test plan, test suits and test cases are developed that are used during different stages of the verification process. There are four phases involved in validation processes: (40) Code Validation/Testing: Developers as well as testers do the code validation. Unit Code Validation or Unit Testing is a type of testing, which the developers conduct in order to find out any bug in the code unit or module developed by them. Integration Validation/Testing: Is carried out in order to find out if different (two or more) units/modules co-ordinate properly. This test helps in finding out if there is any defect in the interface between different modules. Functional Validation/Testing: Is carried out in order to find if the system meets the functional requirements. In this type of testing, the system is validated for its functional behavior. Functional testing does not deal with internal coding of the project, instead, it checks if the system behaves as per the expectations. User Acceptance Testing or System Validation: Developed product is handed over to the user/paid testers in order to test it in real time scenario. The product is validated to find out if it works according to the system specifications and satisfies all the user requirements. As the user/paid testers use the software, it may happen that bugs that are yet undiscovered, come up, which are communicated to the developers to be fixed. This helps in improvement of the final product. (38)
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As the figure above shows that verification and validation process (V & V Process) comes after development process. Verification and Validation are part of the long certification process for any system. There are several reasons why a product needs certification. The legal reasons play as an important role in this certification. (41) "Even though certification does not occur until the end of a system development cycle, the planning starts from the very beginning. Because certification is a complicated process between the developer and the regulatory agency, the certification liaison between the parties must be established early on in the process. Next, the developer should submit a verification plan for approval by the regulatory agency. After the submission, discussion takes place between the developer and regulatory agency to resolve areas of misunderstanding and disagreement. Changes to the methods used have to be approved by the regulatory body to insure that certification will not be affected. Throughout the entire development life cycle of the product, documentation must be continually submitted to show that the certification plan is satisfied. The regulating authority will also hold a series of reviews to discuss the submitted material. At the end, if the terms of the certification plan have been satisfied, then a certificate or license is issued" stated by Eushiuan Tran, verification/validation/certification article. Airbus Company uses this process to satisfy the requirement. Obviously, A380 has unusual design features so this leads Airbus to show that this aircraft is ready to carry 500 passengers. There are several topics that Airbus is concerned with the A380, therefore this project will cover in four main areas: Landing gear, brake and steering system, Hydraulic system, Structural and Design, and Power plant.
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16.Landing Gear, Brake, and Steering System
Landing gear, brake, and steering system is an important primary topic that must be concerned due to the fact that Airbus A380 is the world largest aircraft which consists of thousand components, where majority of components are used had been enhanced with latest technology that the manufacturer of each component must significantly investigate and explore. The A380 landing gear is the world’s largest landing gear that has ever been build to an aircraft. This landing gear consists of 6 main sections which are the following: Gears ï‚· Nose landing gear ï‚· Body landing gear x2 ï‚· Wing landing gear x2
(2 wheels) (Bogie Type, 6 wheels - 4 braked) (Bogie Type, 4 wheels - 4 braked)
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Extension/Retraction System
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Braking Control System
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Steering Control System
ï‚· ï‚·
Nose Wheel Steering Body Wheel Steering
Wheels, Tires and Brakes (16 Braked wheels)
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Monitoring Systems
ï‚· ï‚· ï‚·
Tire Pressure Indication System Brake Temperature Monitoring System Oleo Pressure Monitoring System (OPMS)
The design of this landing gear must satisfy the basic requirements, for that reason there are two minimum requirements manufacturers must comply with ICAO code E and FAA group V airports: 1. 45m runways and 23m taxiways 2. Possible U-turn on 60m wide runway
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16.1.
Equipment Tests
16.1.1. Nose Landing Gear Messier-Dowty was selected to design, manufacture, test, and support the nose landing gear for the ultra-large Airbus A380 Aircraft in 2001. Messier-Dowty has a long experience on all existing Airbus Aircrafts. In the forward retracting nose landing gear, it introduces many modern technologies such as the use of an HVOF (High Velocity Oxygen Fuel) surface treatment process to replace the use Chromium plating, which is more environmentally friendly, and a 350-bar hydraulic system which never been used before on large commercial aircraft. (42) Main components of the A380 nose landing gear are: Main fitting and sliding tube, both were produced in Montreal, Canada and in Bidos, France, respectively. Nose landing gear main testing took place in Gloucester, UK and at the CEAT center in Toulouse, France. Eight of A380 nose landing gears were manufacturer in 2004.
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In January, 2004 - The A380 nose landing gear were delivered to Airbus UK. Standing at 4.8 meters tall when fully extended, the gear were fitted to the Airbus system test rig located at Filton, England for validating aircraft system performance. During nose landing gear test, it showed that nose landing gear is more environmentally friendly due to the use of new materials. The nose landing gear is capable of absorbing and transmitting the towing forces which essential to overcome the inertia of a fully landed aircraft. Additionally, the hydraulic system generates more power while enhancing its performance. (43)
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Airbus A380 Nose Wheel Steering (NWS) assembly. It can move more and less than 60 degree in Towing angle. For hydraulic steering angle, it can move more and less than 70 degree, and can move more and less 75 degree in mechanical stop angle.
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16.1.2. Main Landing Gear Airbus A380 main landing gear was developed by Goodrich Corporation, one of the world's leading suppliers of landing systems for commercial and military aircraft. Goodrich Corporation provides the body and wing landing gear for Airbus A380. In April, 2005 - Goodrich Corporation established the world's largest landing gear test facility in Oakville, Ontario, Canada. A super rig test was tested in this facility. Moreover, the structure of the A380 body and wing landing gear was tested in this facility which covered strength and fatigue testing issues. The test rig rests in a cavity 55 meters long and stands approximately 8 meters high. Additionally, the facility also provides rigs for endurance testing. (44) After suspending the 12,000 pound body gear 12 feet high above concrete, LMS engineering performed an Experimental Modal Analysis (EMA) modal test to A380 body landing gear. This test allowed Goodrich to validate FE models of this rather complex mechanical assembly. Mr. Alvin Fong, Manager of Landing Gear Performance at Goodrich's Oakville landing gear facility commented on the test "The six-wheel landing gear system weighs approximately 12,000 pounds, and its size exceeds 25 feet when fully extended. In landing gear system development, it is our task to meet the required modal stability and structural performance to ensure that the gear will safely react to all loads and circumstances it will encounter throughout its service life."
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The test set-up required LMS to fabricate two solid stands with 5,000 pounds for each fill. LMS decided to pre-load the body landing gear unit with static forces for avoiding free-play in landing gear joint. LMS engineering decided to install two electro-dynamic shakers which can generate 1,000 Newton peak forces in order to provide sufficient energy while performing modal tests on a specimen of this size and weight. During the first time test, the modal test showed that the test rig exhibits around 8 Hz. After this test, LMS engineering added a number of rig measurement points to the modal test geometry of the landing gear unit. (45) To verify the quality of the modal test set-up, Paul Weal, Business Development Manager of LMS Engineering Services said “When evaluating structural FRF coherence and reciprocity, the two burst-random shaker inputs created only limited nonlinear landing gear behavior in static stroke and extended positions, at specified force levels between 5 and 15 Newton."
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The major mode shapes extracted from the test data were used to verify finite-element landing gear models at Goodrich and supported structural investigations at Airbus.
Additionally, Paul Weal said "However, when increasing force levels firmly using stepped-sine excitation - 200 up to 1,000 Newton - we identified stronger non-linear behavior, mainly as a result of slight backlash that was present in the huge landing gear joint connections. When testing at highest force levels, the resulting bending and torsion modes became truly visible, as we witnessed displacements of about 1 inch. With the help of driving point FRF functions, we quantified the evolution of growing non-linearity that is exhibited in response to increasing force levels."
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The actual model analysis test campaign started after the selection of the landing gear modes. The most significant modes retrieved for the landing gear static stroke configuration were foreaft, lateral and torsional resonance below 15 Hz. For extended Stroke, the identified fore-aft, lateral and torsional modes were lower than static stroke modes. In general, the measured modal frequencies turned out to be lower than then- predicted counterparts. The project confirmed the model characteristics of the starboard body landing gear system. The major mode shapes extracted from the test data were used to verify FE landing gear models at Goodrich and supported structural investigations at Airbus.
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After suspending the 12,000 pound body gear 12 feet high above concrete, they applied burst-random and steppedsine excitation up to 1,000 Newton force levels.
Test also explored potential dynamic influences of the Super Rig on the mode shapes of the actual landing gear. The model analysis showed strong coupling of the landing gear and test rig dynamics, particularly in the 5 and 8 Hz regions.
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To be able to provide sufficient energy while performing modal tests on a specimen of this size and weight, LMS engineering consultants installed multiple shakers.
In July, 2005 - Airbus Company announced that the test of the A380 wing and body main landing gear is in expected levels. The test was designed to go way beyond the limit of normal operations and was the equivalent of the structural static airframe tests to destruction. (46)
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16.1.3. Landing Gear Extension and Retraction System In April 2002, Smith Aerospace started a contract with Airbus to supply A380 landing gear extension and retraction system. This contract is the fourth contract on the new 555 seat aircraft. The previous contracts are wing flaps and slats, landing gear actuation, and fabricated assemblies for the wing structure. (47) Highly Accelerated Life Testing (HALT) was used to evaluate the performance of Airbus A380 landing gear extension and retraction (LGERS). This is the first time for HALT to use for hydro mechanical systems. Moreover, it took advantage of new materials to reduce the system's weight. (47)
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Highly accelerated lift testing (HALT) of the pitch trimmer actuators – conducted to investigate the effects of high frequency dither on the seals.
The component of up locks, valve housings, actuators and pitch trimmers have been completely investigated at Cheltenham and Yakima, Washington, USA. In test rig, Smiths tested the electrical actuated gear and door up locks. Rob Neal, actuation systems engineering director said "the use of electrical actuators will save 200 kg (440 lb) by eliminating mechanical pull cords on the emergency release system."
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Three A380 electromechanical up locks: in varying states of build and reserved for environmental, vibration and endurance testing. All have yet to be fitted with their normal unlock actuators, and only the one on the right is fitted with its two electro-mechanical emergency unlock actuators.
Airbus A380 is the first large civil aircraft to use High Velocity Oxy Fuel (HVOF) for seal wear reduction consist of actuator piston rod coating. Technically, HVOF is a method of deposition of tungsten carbide materials, and is a replacement for what is regarded as the environmentally unfriendly method of chrome-plating. HVOF also produces an exceptionally smooth surface; a chrome-plated surface can have microscopic fissures which at 5000-psi could allow leaks to occur.
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16.1.4. Brake and Steering System Airbus Company has made 5 major equipment contracts with Messier-Bugatti. These contracts are as the following: ï‚· ï‚· ï‚· ï‚· ï‚· The forward and main steering systems Tire, brakes and landing gear monitoring system Electro-hydraulic pumps for flight controls The "Full Brake By Wire" type brake regulation system Distribution and filtration system equipment in the hydraulic circuits of the aircraft
16.1.4.1.
Braking Control System
Messier-Bugatti's decided to use two main circuits for controlling the braking system, one is the main circuits which are driven by dedicated software in the Integrated Modular Avionics (IMA) suit, and another alternative has an analog computer to control. Messier-Bugatti supplies the entire braking control system, including: 1. 2. 3. 4. 5. 6. IMA software Three RDAs with software EBCU backup computer Hydraulic equipment All sensors Decentralized hydraulic generators
In the mid of 2004, Messier-Bugatti completed the first series of tests on its new WABSIC (Wheel and Brake System Integrated Components). This is the first step on the road to qualification. This test was to validate the system's innovative concept under different braking conditions. Moreover, during the test, the observer investigated the comprising annular tachometer and tire pressure sensor with wireless transmission of data from the WABSIC. (48)
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16.1.4.2.
Steering System
There are two different steering systems: Nose wheels and Main landing gear wheels. The hydraulic circuits (at 5,000 psi) are the main circuit that uses to drive the two nose wheels. For the main landing gear, there is a single circuit which controlled by the braking RDCS
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Hydraulic unit for the A380 steering system on a test bench (Left), A380 brake manifolds, for the wing and fuselage landing gear (Right), Messier-Bugatti
16.1.4.3.
Tire, Brake and Landing Gear Monitoring Systems
The main requirement of improving volume and reliability for the A380 is by providing an evidence of real system innovations. These systems include the Tire Pressure Monitoring System (TPMS), Brake Temperature Monitoring System (BTMS) and Oleo Pressure Monitoring System (OPMS). In the TPMS, the mechanical and electric links connecting the pressure sensor incorporated into the rotating wheel and the fixed axle of the landing gear have been optimized significantly. The OPMS developed for the A380 is world first model. The monitoring data will send directly to the cockpit.
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Brake Temperature Monitoring System (Left), Tire Pressure Monitoring System (Right)
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17.Powerplant
The A380 can be fitted with two types of engines: 1. Rolls-Royce Trent 900 2. Engine Alliance GP7200
17.1.
Rolls-Royce Trent 900
The Rolls-Royce Trent 900 engines power the world's largest airliner, the Airbus A380. The Trent 900 was launched in February 2001. This type of engine is one of the most ambitious engineering programs in the company's civil aerospace history. The Trent 900 is the fourth member of the Trent family and holds pride of place as the largest jet engine ever produced by Rolls-Royce.
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Rolls Royce Trent 900 features: ï‚· Three-shaft architecture that makes the Trent 900 design simple, easy to transport and retain performance. This generation of Rolls-Royce's engine encompasses the latest technology which engineers research for several years. Moreover, Rolls-Royce also established demonstrator programs for providing more reliability and excellent operational capability and maintainability. The most environmentally friendly engine on A380 Due to the fact that our world becomes more concern about environment. Rolls-Royce reflects this campaign by the swept fan design which combined to whole engine design ensures that the Trent 900 meets stringent noise legislation. Reducing emissions is another topic that Rolls-Royce concerned. The Trent 900 by itself has tiled combustor in order to reduce emissions. A contra-rotating high-pressure spool, Trent 900 is the first engine in the Trent family to feature this outlook. There are several advantages in this design such as predictable maintenance system, reduced weight, and more efficient engine with lower fuel consumption. The engine has a baseline take-off thrust of 70,000lb and is certificated up to 80,000lb from the same bill of material. In testing, it has been run up to 93,000lb thrust. Performance of the engine is exceptional, meeting or exceeding all of the next generation targets it has been set. The Trent 900 is the first engine in the Trent family to feature a contra-rotating high-pressure shaft providing a more efficient engine with lower fuel consumption and reduced weight. In addition, QUICK, an advanced predictive maintenance system, has been introduced to reduce maintenance disruption and improve time on-wing. (49)
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17.1.1. Equipment Tests Trent 900 first run was in 2003 where Rolls-Royce decided to develop first seven engines in testing. Rolls-Royce had planned and tested many issues relevant to safety and reliability such as multiple bird strikes test, blade containment test, and water, hail and ice ingestion tests. All of these details will be in the qualification tests. In July 2003, latest nacelles were tested for fitting to the Trent 900. Xavier Bardey, Trent 900 nacelle program manager said “We mean all the mechanics and the electronics which make it possible for the reverser to work. This system, designed by our partner HispanoSuiza, had already been operated on a test rig. At Le Havre, we made sure that the system worked properly on an actual reverser before sending it to Rolls-Royce". These tests took for about two weeks. In late 2003, Rolls-Royce began to test the Trent 900 with bird strikes by simulation program in order to test durability against 2.5, 5.5 and 8 lbs bird impacts.
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Trent 900 Bird strike testing (Left), advanced 3D computer modelling of bird strike testing (Right)
The thrust reverser was tested on the Trent 900 which was used to assess the durability, the resistance of the structure, the vibration and temperature data, the operation of the reverser. After the test, engineers assured that the reverser met the performance objective relating to the air flow which is to be deflected forward on landing for the thrust to be reversed. (50) Rolls-Royce had run a ground-based altitude test which tested in April, 2004. These trials conducted at the U.S Air Force's Arnold Engineering Development Center (AEDC). The other tests are cyclic endurance trials at Derby, England with 150 hours test. The cyclic endurance evaluations ran the engine through 3,000 cycles to simulate airline operations. The type test put the engine through a variety of extreme operating conditions.
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In 2004, the Trent 900 was successfully gone through the blade containment test, which is one of the major safety tests in development of the engine. During testing, a fan blade was released at the root by detonating and explosive charge after the engine reached the maximum speed. (51) At the same time, the Trent 900 was successfully tested the performance testing in various extreme flight conditions including operation under severe icing conditions, altitudes in excess of 40,000 ft at speeds requirement by Airbus Company. Additionally, rain, hail, and ice ingestion has been tested.
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Rolls RoyceTrent 900 water ingestion test
Trent 900 received the certification from the European Aviation Safety Agency in October, 2004. Where required to operate at initially a maximum take-off thrust of 70 000 lbs, but it had cleared at an 80 000 lbs rating, allowing margin for future growth. It reached thrusts in excess of 90 000 lbs during test bed. A year after receiving EASA type certification, the first A380 flight powered by Trent 900 engines successfully took place. Four Trent 900s powered an A380 flight test aircraft began testing that included a cold weather campaign in Northern Canada and high altitude performance test in Colombia, together with hot weather testing in United Arab Emirates.
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Engineers conducting extreme heat conditions testing on the aircraft (Al Ain International Airport, UAE)
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17.1.2. Qualification Tests 17.1.2.1. Bird Ingestion (FAR section 33.76) Rolls-Royce responded to this requirement by demonstrating the capability of the Trent 900 by the impact of a 5.5 lb bird and the result has been completed successfully. The engine has not caused the condition of catch fire, release hazardous fragments through the engine casing or any other severe conditions. Additionally, Mr. Robert Nuttall, Rolls Royce marketing vice-president said "That was a new, high-energy impact test, and it was the first time anyone has done an engine test on that size of flocking bird"
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Rolls Royce Trent 900 brid strike test
17.1.2.2.
Rain and Hail Ingestion (FAR section 33.78)
Water, hail, ice ingestion were successfully completed before the Trent 900 achieved the type certification from EASA in 2004. The representative of Rolls-Royce Company stated with these tests that there was no surging, when experiencing severe and abnormal flight conditions.
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Rolls Royce Trent 900 water ingestion test
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17.1.2.3.
Vibration Test (FAR section 33.83)
The Rolls-Royce and Airbus Company had published that test has been completed in 2003. During the test, the engine satisfied the engineer by having low vibration and proving air and oil system. The Vibro-Meter had developed the Engine Monitoring Unit (EMU) for the Trent 900 engine. The EMU multi-monitor the engine vibration, observe the pressure, temperature and implements advanced algorithms for engine maintenance purposes. (52)
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Trent 900 Engine Monitoring Unit (EMU)
17.1.2.4.
Endurance Test (FAR section 33.87)
The 150 hour "red line" endurance test was completed in May 2004. Rolls-Royce tested the Trent 900 engine cycle-endurance where notch up around 3,000 cycles. This Trent 900 cycle tests included operations of the nacelle and thrust reverser. During the Trent 900 engine experienced the high temperature which was much higher than the other conventional aircraft meet, the engineers also could observe the thermal capability. 17.1.2.5. Engine Over Temperature Test (FAR section 33.88)
European Aviation Safety Agency DATA SHEET Number E.012 claims that "The Trent 900 is approved for a maximum exhaust gas over-temperature of 920 degrees Celsius for inadvertent use for periods of up to 20 seconds without requiring maintenance action".
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17.1.2.6.
Blade Containment Rotor Unbalance Tests (FAR section 33.94)
In July 2004, Rolls-Royce announced to the public that the Trent 900 engine had successfully completed a fan-blade containment test. During the test, the engine was accelerated to full speed before a fan blade was released at the root by an explosive charge. The blade and its debris were contained successfully and the engine performed a control shutdown. The blade-off test was also the first time that Rolls-Royce had performed this crucial test on a production engine fitted with highly swept wide chord fan blade. (51)
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Rolls Royce Trent 900 performing fan blade-off test
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17.2.
Engine Alliance GP7200
Engine Alliance GP7200 incorporates state of the art advanced technologies with a solid heritage of proven wide body products from the world's two leading aircraft engine manufacturers:
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GE Aircraft Engines Pratt & Whitney
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Engine Alliance GP7200 features: ï‚· ï‚· ï‚· ï‚· ï‚· Certificated at 81 500 lbs thrust to support 2006 A380 entry into service requirements. Built on GE90 and PW4000 mature reliability and leading edge technology Superior fuel efficiency World class emissions and low noise Thrust growth capability built in
The environmentally friendly GP7200 meets all ICAO gaseous emissions standards with substantial margin. According to EADS certification test data, the GP7200 powered A380 is the quietest A380. From Noise point of view, Engine Alliance GP7200 is a good neighbor where allowing the A380 to meet current stage 3 and proposed stage 4 noise level standards with margin.
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17.2.1. Equipment Tests The first GP7200 engine was completed in March, 2004. The GP7200 began test phase with sea level testing before beginning altitude testing at Arnold Engineering Development Center in Tennessee. (53)
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Engine Alliance and P&W GP7000 Project General Manager, speaks to the team that completed the final assembly of the first GP7200 engine.
The mechanical break-in cycle of the engine testing was complete in April, 2004. The GEP&W Engine Alliance's GP7200 engine has produced more than the 76 500 lbs of thrust required for entry into service on the Airbus A380 aircraft during its initial testing. The engine reached 80,000 pounds of at Pratt & Whitney's test facility in East Hartford, CT. Moreover, the mechanical stress is in the acceptable level. (54) At the same period of time, approximately one month of sea-level testing at P&W's facility, the engine ran 45 hours and achieved 86 500 lbs of thrust in the Airbus configuration (88000 lbs measured in cell conditions). The first engine to test (FETT) program also mapped the performance of the engine's advanced swept fan. After finishing test, Lloy Thompson, president of the engine Alliance stated that "This is one of the most successful FETTs I have seen". The next stage of this first engine is to undergo altitude testing.
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Engine Alliance GP7200 FETT
In July, 2004, ground testing was under way on the GP7200 engine. Prior to service entry, the GP7200 program will accumulate more than 20 000 endurance cycles and 7 000 hours of operation on eight test engines. (55) During ground testing, the engine Alliance's GP7200 engine is exceeding performance expectations for specific fuel consumption and exhaust gas temperature margin. First GP7200 engine reached 88 000 lbs (391kN) thrust exceeding the 70 000 lbs (311kN) thrust required for entry into service. The second development engine began ground testing with a 700 cycle's endurance test to evaluate hardware durability at operating conditions more severe than expected in airline service. The FAR 33 certification follows an extensive ground and flight-test program that involved eight engines over 21 months. During its development and certification program the GP7200 ran some 7 000 cycles, 25 full-scale engine certification tests and more than 50 component tests and powered two flight-test programs on a flying test bed. The engine is initially certified at 76 500 lbs of thrust and has the capability to produce over 81 500 lbs with the same bill of material. During its certification program the engine was tested at thrust levels in excess of 94 000 lbs. (55)
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The Engine Alliance’s GP7200 engine is undergoing extensive testing at GE’s Peebles Test Operation
Additionally, Bruce Hughes, Engine Alliance president said "We put the GP7200 through as tough a test regime as any engine has ever faced. Even though the engine will be used on the four-engine A380, we tested and certified it to the same standards required for large twin-engine aircraft in ETOPS (Extended-Range Twin Engine Operations). This has been an outstanding team effort by the Engine Alliance, its parent companies GE and Pratt & Whitney, and its partners, MTU, Snecma and TechSpace Aero. Now we are ready to get on with flight-testing and certification on the A380."
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Pratt & Whitney's full-scale Geared Turbofan demonstrator engine during a nacelle system fit check.
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Engine Alliance GP7200 being tested at AEDC (Left), Icing test facility at AEDC (Right)
First GP7200 flight test commence in December, 2004 being fitted to Boeing 747. This first flight took nearly three hours especially for initially assessing the engine operation as well as gathering propulsion system data on the nacelle and accessories. The initial series of seven flight tests will wrap up by the end of 2004. The GP7200 engine has been tailored to satisfy both current and future thrust requirements of the A380 family of aircraft. (56) Engine Alliance has reached a major milestone in the development of its GP7200 engine with delivery of the first four compliance/flight test engines for the A380. Nacelle and aircraft system components were installed in this engine. GP7200 engine provides 70 000 lbs of thrust for the A380 with capability to more than 80 000 lbs.
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Engine Alliance Delivers First A380 Engines to Airbus
In tests, engines showed that they performed flawlessly and have met all critical targets for performance, durability, noise and emissions. In-flight performance measurements confirms that GP7200 engine is the most fuel-efficient engine for A380 aircraft as a consequence of burning less engine fuel than Airbus Company's requirement. (57)
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After 16 months of flight testing, the engine Alliance GP7200 powered Airbus A380 finally received type certifications from the European Aviation Safety Agency (EASA) and the Federal Aviation Administration (FAA) in December, 2007. (57)
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Engine Alliance President Bruce Hughes (right) is shown presenting a collage of the program’s history to Airbus Executive Vice President Mario Heinen at the EASA certification ceremony in Toulouse, on December 14, 2007.
Type certification is an indicator that GP7200 ready for Airbus A380 after having accumulated 240 flights and 2 855 engine flight hours. Moreover, the GP7200 engine has amassed more than 5 250 hours and 17 760 cycles of endurance ground testing. The representative of Airbus Company, Mario Heinen, and Airbus Executive Vice President said at the EASA certification ceremony "The GP7200-powered A380 has been performing extremely well throughout the development and certification program, the aircraft is consistently meeting and often exceeding its design targets".
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17.2.2. Qualification Tests 17.2.2.1. Bird Ingestion (FAR section 33.76) In June 13, 2005 - Engine Alliance successfully completed three separate bird ingestion tests with four 2.5 lbs flocking birds, a 5.5 lbs and an 8 lbs bird. During the test, the engine has not caused any severe of adverse condition including catch fire, release hazardous fragments through the engine casing, generate loads greater than ultimate loads or lose the ability to be shut down. 17.2.2.2. Rain and Hail Ingestion (FAR section 33.78)
According to CS-E 790(a)(1) requires that " The ingestion of large hailstones, with the engine at maximum continuous power/thrust, must not cause unacceptable mechanical damage or unacceptable power or thrust loss after the ingestion, or require the engine to be shut down ". The GP7200 was tested on this requirement and the result satisfied the regulation. However, there are two effects of the large hailstone ingestion should be considered: the mechanical damage due to the kinetic energy of the ice, and the ingestion by the engine of the corresponding mass of ice or water. (57) Power or thrust loss caused by the ingestion of ice or water: Ingestion of large hailstones does not adequately assess the effect of ice or water ingestion on the engine. This is actually evaluated by testing in accordance with CS-E 790(a) (2). Compared with CS-E 790(a) (1), much more liquid water and ice are ingested during testing in accordance with CS-E 790(a) (2). This ESF concerns only CSE 790(a) (1). The engine will be fully tested in accordance with CS-E 790(a) (2) and no equivalent safety finding is necessary to demonstrate the engine capability to ingest water or ice. (57) Power or thrust loss, or necessity to shut down the engine, caused of mechanical damage: The safety objective in term of mechanical damage is comparable with the one of CSE 800. Means of compliance other than complete engine test are accepted for CS-E 800, it is therefore reasonable to also accept these other means of compliance for CS-E 790(a) (1). Before publication, the ESF document will be revised to mention that, in such a case, the content of CS-E 800(f) (1), and related AMC, need to be taken into consideration when using these other means of compliance for CS-E 790(a) (1).
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17.2.2.3.
Vibration Test (FAR section 33.83)
Engine Alliance GP7200 vibration test has been tested in February, 2006. The first of four Engine Alliance GP7200 engines has been installed on the fifth A380 test aircraft. It has been published that the vibration tests have been successfully carried out trials including aerodynamics, and low speed at the same time. 17.2.2.4. Endurance Test (FAR section 33.87)
The GP7200 development engines had 150 hours block endurance testing. The eightengine GP7200 test program accumulated more than 15 000 endurance cycles. A representative of engine Alliance stated "Service ready". In addition to flight-testing, GP7200 factory engine endurance ground testing has amassed 4 349 hours and will accumulate an additional 3 000 cycles of maturity prior to entry into service. 17.2.2.5. Engine Over Temperature Test (FAR section 33.88)
Engine Alliance tested GP7200 to qualify this requirement by operating the engine at maximum rating's steady state approximately 970 Celsius. Moreover, GP7200 has been tested for more than five minutes with the turbine gas temperature at maximum permissible rpm about 1002 Celsius. 17.2.2.6. Blade Containment Rotor Unbalance Tests (FAR section 33.94)
Engine Alliance GP7200 has successfully conducted fan blade-out containment in November, 2004. During the test, the GP7200 showed that the engine could hold the damage without any failure of the attachments and catching fire.
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18.Hydraulic System
Weight is one of the most concerned issues in aircraft manufacturers. Every extra pound contributes to fuel costs and also affects to the bottom line for the airlines. Airbus Company makes a challenge decision by changing 3 000 psi hydraulic systems as other passenger aircraft to 5 000 psi hydraulic systems. Eaton Corporation was selected by Airbus Company to provide the 5 000 psi hydraulic power generators for the A380. The system is made of: 1. Eight Vickers PV3-300, 2. Thirty one engine-driven hydraulic pumps, along with 3. Four AC motor pumps and 4. Electronic control and protection systems. The pumps are pressure-compensated variable displacement type, and deliver 42 gpm at 3775 rpm.
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A380’s Hydraulic system (5000 PSI)
There are two outstanding aspects set this pump apart. First is the disengagement clutch, in case of a pump cannot operate while on ground, the clutch can segregate the pump from the system and this will allow airplane to be dispatched by using the remaining seven pumps. Moreover, Phil Galloway, engineering manager of Eaton said "The pump cannot re-engage except on the ground, via manual means." Secondly, the PV3-300-31 by itself provides low noise and pressure pulsation. It provides pressure in a given 5 000 psi system might vary from 4 900 to 5 100 psi.
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Switching to use 5 000 psi hydraulic systems is not easy tasks to do due to some extremely serious pump design issues at higher pressure as shown below:
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Stresses Material Selection Deflections Pressure Time Velocity Factors Pressure Balances Efficiency, and Pressure Pulsations
Computational fluid dynamics is also used to minimize pressure drop in critical areas. For material selection, the 5 000 psi hydraulic systems almost rely on steel or titanium. "Pulsations can be minimized with the use of pulsation attenuators, essentially fluid volumes added to the outlet line of the hydraulic pump. The size of the attenuator is a function of the size of the pump and the amount of attenuation desired. The drawback to large attenuators is that the weight can be significant, as a high pressure volume is required" said by Phil Galloway, Engineering Manager of Eaton. Messier-Bugatti is another company which relevant to hydraulic system development for Airbus A380, they also focus on developing high-tech components which demanded sophisticated computer modeling.
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EHA mini-pumps for A380 flight control: ailerons, rudder and elevator
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18.1.
Equipment Tests
There are several components which relevant to A380's hydraulic system and these components are also investigated by many companies. Being easy to classify, this section will divide components by company. 18.1.1. Eaton Corporation
In October, 2001 - Airbus has selected diversified industrial manufacturer Eaton
Corporation to provide the hydraulic power generation system for the world's largest commercial airliner, the A380. According to this contract, it allows Airbus Company to achieve significant weight savings from fluid conveyance and actuation component volume reduction throughout the aircraft's structure. (58) The A380 hydraulic system integrates a total of eight Engine Driven Pumps (EDP). This architecture allows having one EDP as a go item which means the aircraft can be dispatched normally with one off-line EDP while using the remaining seven pumps.
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A380 Hydraulic System Block Diagram
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18.1.1.1.
Engine Driven Pump
There are eight Eaton Vickers brand Engine Driven Pumps (EDP) on the A380 which provide the main hydraulic power for the 5 000 psi system. During the test, it showed that in each EDP delivers a rated flow of 160 L/min at 3775 rpm. Moreover, this pump integrates an 11 piston rotating group coupled with a spherical type attenuator, a boost impeller, and a scavenge pump. (59)
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18.1.1.2.
AC Motor Pump
The 21.3kw 5 000 psi AC Motor pump is the largest developed to date for an aircraft. After testing each Eaton Vickers brand AC Motor pump by powering 115 VAC 400 Hz to each Vickers, it gave a result that can deliver a max flow of 38 L/min with a constant horse power characteristic. (59)
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18.1.1.3.
Fire Shut-Off Valve (FSOV)
There are four Fire Shut-Off Valves which fit to the A380. These valves are used to shut-off the hydraulic line at the pump inlet in the event of major system or engine failure. The FSOV is fitted with size 32 hydraulic ports and provide a nominal flow of 350 L/min under a pressure of 220 psi from the testing. (59)
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18.1.2. Messier-Bugatti Messier-Bugatti can analyze system's hydraulic behavior in terms of performance, stability and robustness due to the LMS Imagine Lab Ground Loads solution modeling and analysis capabilities. These results were used to establish the sizing, output and other product specifications for the entire hydraulic power generation system including the tank, pump and accumulator. (60)
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A380 nose wheel steering AMESim simulation/test bench results comparison AMESim model matches real system behaviour.
Messier-Bugatti simulated the behavior of the electro-hydraulic system for the A380 which validate system power-generating performance and enable engineers to accurately size components early in development.
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Local Electro Hydraulic Generation System (LEHGS) with its Electronic Control Unit (ECU)
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18.1.3. FR-HiTEMP This is one of the UK's leading aerospace component manufacturers, which specializes in fuel, ducting, actuation, and control systems for aero engines, missiles and military vehicles, supplies most of the world's aircraft manufacturers and also supports airlines. During the test, two special Carbolite thermal cycling chambers were installed to test hydraulic systems on the A380. There are some components of hydraulic system position around the massive Trent 900 or GP7200 engines, while other parts are in the wings. These components usually have temperature from -55 degrees to +90 degrees Celsius. (61) The thermal chambers are used to replicate the service temperatures while components are subjected to pressure impulse testing up to 6 000 psi (400 bars). The chambers have a thermal range from 70 degrees Celsius to+150 degrees Celsius.
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Thermal chambers test Airbus hydraulic systems
Liquid nitrogen, pressure relief valves and exhaust vents are used to cool the chambers while heating is by mineral-insulated metal-sheathed elements. Temperature stability and uniformity are better than ± 5 degrees Celsius. (61)
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19.Structural and Design
This topic contains only ground tests which are performed before flight tests so the investigator must significant concern this phase. There are several new components and new technologies in ground tests due to A380 unusual design features. In April 2003 – Airbus is about to start structural assembly of the first major A380 components around European plants, as half of design drawings has been released to manufacturer. At the same time, new wing plant was almost finished, and wing assembly was due to be fit together by October, 2003. The first wing skin/stringer attachment was successfully completed. Charles Champion, Airbus vice-president A380 program said "Around 18 000 of the 35 000 design drawings have now been released to manufacturing and all the basic structural design drawings have been released. We are now concentrating on detail design such as systems, plumbing and wiring bundles”.
19.1.
Ground Tests
Ground tests are classified into three main sections: 1. Fatigue tests 2. Wing tests 3. Cabin tests. In each test, it shows how Airbus satisfies the safety and reliability. 19.1.1. Fatigue Tests Airbus Company has awarded a contract with Industrieanlagen Betriebsgesellschaft (IABG) for testing the fatigue life tests for the A380. Prof. Rudolf Schwarz, Chairman of the IABG Management Board said "We have been involved in the fatigue tests on the Airbus aircraft since the first A300 at the beginning of the 1970's. The cooperation with IMA in Dresden has already proven itself Excellency during the current tests on the A340-600 here in Dresden and contributes to the fact that Germany enjoys an outstanding reputation in Europe for the performance of fatigue tests on large and complex aircraft structures”. In September 2004 – IABG made preparation for the most extensive fatigue tests on A380 aircraft. This test was located in Dresden, Germany by shipping five sections of the new Airbus A380 from Hamburg. The structure then be assembled and integrated in the IABG test facility. (62)
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Testing aim was to verify the fatigue life of the complete aircraft fuselage for the planned operational period of about 25 years. The total period of test is approximately 26 months. The standard safety requirement with the design target of 19 000 flights but this test expected to simulate the loads for 47 500 flights which are more than three times of the requirement. The new process which created by IABG was used in testing A380 and was used on A340-600.
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Fatigue strength test on the new wide body aircraft Airbus A380
According to IAMG, overall facilities consist of a comprehensive test rig accommodates the test structures, integrated hydraulic load unit with almost 200 cylinders where these hydraulic cylinders simulate, in conjunction with specially developed load induction systems, similar loads on the test structure as they would occur in operational flight. IAMG facilities have Control and monitoring system of the 250 channels, as test structure loading is recorded using a metrology unit which permits the measurement and recording, on 7 200 channels mainly on material strain, pressure, temperature and deformation values during the course of the test. In June 2005 – IAMG representative, Klaus Woithe and Airbus Project Manager stated that the first 5 000 simulated flights have gone off smoothly up to this date. A hydraulic loading rig equipped with 182 pulling simulated the load placed on the primary structure of the A380 in flight operation. "Whiffle trees" is a device that has been used to load the structure over 1 700 points. Whiffle trees simulates structure as real life loads affecting the aircraft such as the wings have to be able to withstand 4.5 meters upward deflections and 1.5 meters for downward deflections. Applied forces were simulated as 160 tones that act on each of the four main A380 undercarriages when in service. (63)
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The whiffle tree structure used to do a torsion test
In May, 2006 – Airbus Company reached a milestone in Dresden, Germany. The fatigue tests on the A380 reached 10,000 flight cycles. During the test it can examine the A380's structural behavior by simulating structural stresses over a very condensed period of time. Charles Champion, Airbus COO and Head of the A380 program declared that" This major milestones is underlining the excellent progress of our A380 test program and 10 000 flight cycles is already twice as much as we need for certification”. The fatigue test has passed the 15 000 simulated flights which is three times the 5,000 flight needed for certification in July, 2006. In this test, hydraulic actuators were attached to the aircraft structure and loads were applied to the wings and the fuselage to simulate forces during a typical flight. (64) 19.1.2. Cabin Tests The dimensions of the Superjumbo allow for both flexibility and creativity in cabin design. The A380 provides 50 percent more floor space than the B747 but only 35 percent more seats. The remaining 15 percent of space is available for customized areas without penalizing the seat count. The assembly process is very complex due to the configuration of one deck which differs from other, with different combinations of seating classes.
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Typical A380 cabin configuration
In March 2006 – Airbus Company successfully completed the first extensive ground cabin tests in a fully equipped Airbus A380. It took five hours in this test by using 474 passengers and 20 crew members simulated a 15 hours flight. During flight, Both passengers and crew members tried all cabin systems such as the water and waste system, kitchens and air conditioning system, and in-flight entertainment system. (65)
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Emirates A380 First-Class private suites
Airbus Company assigned individual tasks for all passengers on board test flight for performing at certain intervals in order to simulate a maximum stress on certain cabin
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systems. One of the tasks is to test the performance of in-seat power supply (220v/110v switchable) by using notebooks. All of the cabin managements such as full meal service, and galley and trolley lift operations were included in this test. (65) 19.1.3. Wing Tests In each A380 wing has eight spoilers which are located on the top of the wing. In landing condition, Airbus A380 weight approximately 380 tons and the landing speed is around 280 km/h. In landing condition, all eight spoilers are extended by means of hydraulic cylinders for helping to achieve the drastic reduction in speed. According to Airbus Company, "The function of the extended spoilers is twofold: firstly, they reduce lift while allowing enhanced wheel grip, as in Formula 1 vehicles, and secondly, they increase aerodynamic drag, thereby taking on a considerable portion of the overall required braking effect. Moreover, the spoilers can also be used for specific operations during flight, such as supporting the control flaps while carrying out flying maneuvers, or causing a rapid drop in speed or altitude”. In May, 2005 – IABG tested spoilers on the new Airbus A380 where they set up two main tests: static and dynamic tests. Each test consists of a test rig, either nine or seven hydraulic cylinders, and four devices known as "whiffle trees", which simulates the distribution of aerodynamic forces. (66)
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Setup for the Spoiler Test of the Airbus A380
Static tests initially involve simulating the limit load that can conceivably be reached during flight, then load is increased to one and a half times this limit, or ultimate load. The spoilers must be capable of taking this load.
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Dynamic tests involve testing whether the spoilers can undergo 19 000 simulated flights without showing signs of fatigue. This represents the intended service life of the A380, for this purpose, components are loaded with every conceivable force that could cause damage over time. IABG simulates loads not only over an individual aircraft service life, but also over a double aircraft service life for one of the spoilers, and 3.6 times a service life for the other. Furthermore, the components are weakened by artificial aging and artificial defects. The fatigue tests are interrupted at regular intervals in order to inspect the test samples for possible fatigue damage. (66) In February, 2006 – Airbus A380's wing was tested in Toulouse, France. The wing from static test specimen suffered a structural failure below the ultimate load target during the trials. (67) After completing "limit load" tests which is the maximum loads likely to experienced by the aircraft during normal service, the greater loads have been applied to the specimen towards the required 1.5 times the limit load and the finite element method (FEM) has been used to calculate the load requirements. The result of this test was the failure at a point between the inboard and outboard engines between 1.45 and 1.5 times the limit load. Alain Garcia, Airbus executive vice president engineering declared after the test finished that "This is within 3% of the 1.5 target, which shows the accuracy of the FEM and the ultimate load trial is an "extremely severe test during which a wing deflection of 7.4m (24.3ft) was recorded”.
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Airbus has been running load trials on a full scale A380 static test specimen in Toulouse since late 2004
European Aviation Safety Agency (EASA) reflected this test by said that the maximum loading conditions were defined in the A380 certification basis. The aircraft structure was
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analyzed and tested to demonstrate that the structure can withstand the maximum loads, including a factor of safety of 1.5. (67) The FEM was used to prove the adequacy of the A380's structure on production aircraft. Airbus had refined the structural design for subsequent aircraft due to increased weights, according to Alain Garcia, Airbus executive vice president engineering.
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Airbus performing bending test on A380 wing
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A380 FEM wing model
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20.Flight Tests
The maiden flight test for Airbus A380 was in April, 2005. The world's largest commercial aircraft successfully took off with six crews and approximately 20 tones of test equipment from Blagnac International Airport in Toulouse which is its production site. This flight took about four hours circling the Bay of Biscay. For this first flight, Airbus A380 took off at weight of 421 tones or 928 300 lbs which is the highest weight ever of any civil airliner. Four Rolls-Royce Trent 900 engines powered the A380 to fly on the sky. Thousands of parameters which important to enable in-flight performance analysis were recorded during this flight test. (68)
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A380 Super Jumbo Jet Makes Maiden Flight
Claude Lelaie, test pilot said after A380 landed "You have seen a lot of ground tests, a lot of wind tunnel tests, simulators -for the first time you can see all the systems working together in the real world in the air, a new page of aeronautical history has been written. It is a magnificent result for European industrial cooperation”. The first flight is the beginning of a flight test campaign involving as many as 2 500 hours of test flights on a total of five development aircraft. This rigorous sequence of test flights will lead to the certification of the A380 by the European and US airworthiness authorities which allow the world's largest commercial airliner to enter into service in the second half of 2006 with Singapore Airlines being a first commercial operator.
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MSN 001 First test aircraft, to be retained by Airbus MSN 002 Flight test aircraft. Third aircraft to fly. Will be delivered to Hamburg later this year and will be used first for evacuation tests, then fitted with working cabin (including Thales IFE) for “early long flights” and then for route proving. Will be refurbished and delivered to Etihad MSN 003 First weight-conforming aircraft and first aircraft for Singapore Airlines MSN 004 Flight-test aircraft. Second A380 to fly. Workhorse for performance trials. Will be refurbished for Etihad MSN 005 Customer aircraft MSN 006 Customer aircraft MSN 007 Fourth test aircraft to fly, second with working cabin (Panasonic IFE). Will be used for route proving, and later re-engined with GP7200 engines to join MSN 009 for GP7200 route proving. Will revert to Trent power and be refurbished for Etihad. MSN 008 Singapore Airlines MSN 009 Flight-test aircraft. Leads certification with GP7200 engines. Will be re-engined and refurbished for Etihad
Airbus A380 flight test schedule from MSN 001 to MSN 009
20.1.
MSN 001
There are five A380s in the flight test program. MSN 001 heavily instrumented and fitted with a double row of ballast water tanks which completed envelope expansion and retained by Airbus for further testing. MSN 001 explored the flight envelope, evaluate the cruising performance, the noise impact, determine Vmu and complete accelerate-stop tests and X-wind behavior. In December, 2005 – The demonstration of the A380's maximum design speed (Vmd/Mmd) reaching 0.96 Mach as it shows that A380's flight envelope has been successfully marked. During the test, A380 dived to around 39 000ft (11 900m) and reached 0.96 Mach with pitching down attitude was only 7 degrees. The noise evaluation has been successfully tested at Moron airbase in Spain for four days. It showed from this test that the A380's external noise can be achieved with the current configuration. The aircraft complete over 100 flyovers to measure approach and take-off noise.
20.2.
MSN 002
According to Airbus Company, MSN 002 is the next test aircraft in the manufacturing sequence with testing cabin systems especially on over long flights. This program took approximately seven months which divided into two sections. First is preliminary test which took one to two months. Secondly, a full complement of passengers from Airbus employees was carried in the later four to five months. This allowed environmental control systems, in-flight entertainment systems, and galleys.
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During the flight, the Airbus A380 was outfitted at the manufacturer's Finkenwerder facility with an airline style 474 seats cabin layout. The aircraft was then used for a 500h static virtual flight cabin systems tests. However, before being completed the cabin was modified into a high-density 853 seats arrangement for the evacuation trial.
20.3.
MSN 004
MSN 004 also carried heavy instrumentation and was the workhorse for performance testing, for two reasons. First is that Rolls-Royce Trent 900 engines are to a later build standard. Secondly because it is the first flight-test aircraft which is close to the specified manufacturer's empty weight (MEW). In October 2005 – MSN 004 joined the flight test program. Fernando Alonso, Vice-president Flight tests said “It completed the main evaluation of cruise performance on 9 November and there are complementary evaluations continuing until the end of December, and A380 could end up cruising slightly faster than its nominal published speed of 0.85 Mach”.
20.4.
MSN 007
MSN 007 was due to ferried to Hamburg for its cabin installation in February 2006. It was set to undertake the route-proving program and later be re-engined to conduct route proving of the Engine Alliance GP7200 powered version. MSN 007 is the fourth test aircraft that took 300 hours of route proving. MSN 007 had a Panasonic system which differs from MSN 002 that had Thales IFE system.
20.5.
MSN 009
Assembly of the main Engine Alliance flight test aircraft has been successfully completed in MSN 009. According to Airbus, the certification of A380 powered by GP7200 was received in the first quarter of 2007 to enable deliveries to begin to launch customer. MSN 009 joined MSN 007, which fitted with GP7200 after its initial tests and used for routeproving with the Alliance engine.
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20.6.
Crosswind Landing Flight Test
In October, 2007 – Airbus A380 started crosswind landing certification tests in Keflavik with 40 to 50 knot crosswind. There is a technique which leads to the success flight test; the technique is to fly crabbed down to flare height then kick the rudder to align the nose. Some crab at touchdown is acceptable and will be cancelled as the main gear also aligns the bird with the runway. (69)
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A380 Crosswind landing
20.7.
Natural Gas as a Fuel Alternative
Airbus believes that fuel alternative will become more useful in around 2015, due to the Airbus decided to have a chance for flying A380 with natural gas. In February, 2008 – Flight test took about 3 hours flight by a double-decker A380 flew from Filton, Britain to Toulouse, Airbus headquarters. The giant aircraft's unmodified engine was powered by a blend of gas-to-liquid (GTL) fuel and kerosene. (70)
20.8.
High Altitude and Hot Weather Testing
In October, 2006 – Airbus A380 powered by GP7200 returned to Toulouse after completing high altitude and hot weather testing in Africa and the Middle East. A380 landed in Addis Ababa, Ethiopia where the airport is 7 627 feet (2 325 meters) above sea level. For hot weather campaign, Airbus A380 confronted the conditions of up to 40 degrees Celsius. The aircraft performed five test flights to evaluate engine performance at high altitude conditions, including engine takeoff performance characteristics, ground staring and transient operations.
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A380 during hot weather testing
Bruce Hughes, President of the Engine Alliance said "We continue to be very pleased with the GP7200's in-flight performance, and the engine's fuel burn performance continues to track at or better than our specification to Airbus and all other parameters are performing just as we expected, even in the punishing high and hot conditions of Addis Ababa and Al-Ain”.
20.9.
Cold Weather Trails
In February, 2006 – Airbus A380 returned from Iqaluit, Canada after completing cold weather test. During testing, the full functionality of the systems had been tested under extreme weather conditions of up to minus 30 degrees Celsius for five days.
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A380 during cold weather testing
Test included powering up the aircraft, the engines and hydraulic systems after a full 12-hour period at such low temperatures. The batteries were taken away overnight and kept in a warm area. Batteries were reinstalled onboard the aircraft for the tests in the next morning. (71)
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21.Route Proving
Airbus A380 Technical route proving is the last required step to Type Certification after proving its potential in each of equipment tests, qualification tests, ground tests, and flight tests. There are two main routes proving which are A380 powered by Trent 900 (MSN 002), and A380 powered by GP 7200 (MSN 009). The technical route proving started on 13th November 2006 as it’s a great opportunity to show the people worldwide Airbus A380 function and reliability including key airports. During this test, the A380 was powered by four Rolls-Royce Trent 900 engines which used the flight test program MSN 002 where it departure from an airbase in Toulouse, France and flew to ten major international airports in four trips. Singapore and Seoul were the first two stops on 14th November and 15th November. The second trip operated in 18th November in Hong Kong and followed by 19th November in Narita. Third trip was in two cities in China Guangzhou and Beijing on 22nd November, and 23rd November, respectively. (72)
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New York's JFK airport was the first destination of the A380 Route Proving exercise (Left), The A380 visited Hong Kong on Saturday 24 March 2007 during its second route proving trip (Right)
The last trip was the longest trip out of four as it flew around the world via South Pole and North Pole. The trip started from Toulouse to Johannesburg in 26th November and two day later arrived at Sydney via South Pole. A380 route proving showed aircraft performance by flying long-range flight with maximum payload with a maximum take-off weight approximately 555 tones/ 1 223 565 lbs. A380 took only 16 hours from Johannesburg to Sydney covering a distance of 7896 nm/ 13 512km. On 29th November, A380 flew across the Pacific to Vancouver and then returned back to Toulouse via the North Pole. (72)
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The second route proving which was powered by GP7200 started on 26th September 2007. This route proving was also divided into four trips stopover, South America, North America, Middle East and Asia-Pacific. (73) It also commenced for an airbase in Toulouse, France to Bogota, Colombia on 26th November where the aircraft had only spent a day in Colombia and then flew back to Toulouse. The second trips began from 2nd October to 5th October as it headed to three cities in USA, Windsor Locks (Connecticut), Hebron (Kentucky) and San Francisco (California). Third planned trip started on 8th to 13th October where the aircraft spent five days flying to Dubai (United Arab Emirates), Melbourne (Australia), Manila, and Luzon (Philippines) and back to Dubai (United Arab Emirates). The last trip was tested on 15th October; the Airbus A380 flew to Bogota (Colombia), Vancouver (Canada), and Osaka (Japan) and then went back to Toulouse on 19th October. After finishing these two main routes proving trips, Airbus A380 was turned around under normal airline operating conditions. (73)
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22.Conclusion and Recommendations
Airbus A380 is the world largest commercial aircraft at this moment, so there is no doubt that people all over the world are focusing on this particular aircraft and would want to stay in contact with. In conclusion this lead aerospace engineer or others who are related to this project should address safety and security issues facing the A380 in service. In this project I’ve started my second part where I begun to talk about the use of V&V process to test the safety and reliability issues. There are 5 main tests used for analysis in this paper: 1. Equipment tests 2. Qualification tests 3. Ground tests 4. Flight tests 5. Rout proving In each test contains details and information from five main criteria that break, Landing gear, break, and steering system, Powerplant, Structural and Design, and Hydraulic system. Airbus A380 is only few years old where information is not easily found even on Internet and published books. In addition, it is very difficult to find in-depth information. This may occur, in connection with the Airbus does not want to announce it in detail or being confidential. Safety and reliability issues are very important factors in the aerospace and aviation industry, for that reason I hope this thesis useful was for those who much enthusiast about the Airbus A380 and the process it went through to satisfy airworthiness regulations. Airbus has done a great job in production of its state of art A380 where it was late in delivery but aircrafts reviewers think it was worth of wait due to high technology and precision built that leads to low maintenance cost and environment friendly aircraft.
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A380 CFD Model
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