An Aircraft Hangar June06

Published on May 2016 | Categories: Documents | Downloads: 60 | Comments: 0 | Views: 376
of 8
Download PDF   Embed   Report

Comments

Content

Application Note

Aircraft

Hangar
Fire Safety

Aircraft hangars present special fire protection problems due to the high value of their contents and the special procedures and operations carried out inside them.

AIRCRAFT HANGAR FIRE SAFETY

Optical flame detectors are used to protect valuable aircraft from fire. Initially the UV and UV/IR detectors were used for hangars protection. Since the introduction of the new Triple IR (IR3) technology over three years ago, it has become the requirement of most hangar designers. The new technology provides: 1. Superior false alarm immunity. 2. Reduce the number of detectors, as the IR3 will see a 1x1' fire at three times greater distance than any other detector. 3. Better coverage of larger hangars, above and under the aircraft wings where the potential threat of fire exists. The SharpEye Triple IR (IR3) Optical Flame Detector provides the aircraft hangar designers with a powerful detector to meet the military and commercial requirements. Extensive evaluation tests conducted by the U.S. Navy, Swedish Air Force and Royal Air Force (UK) have shown the superior performance of the SharpEye Triple IR (IR3) Flame Detectors. Commercial Airlines have also adopted the SharpEye Triple IR (IR3) Flame Detector for their aircraft hangar protection, including special designs/layouts to protect expensive aircraft as well as auxiliary equipment areas. Recent installations include United Airlines facility in Indianapolis (USA), Monarch Airlines, Continental Airlines, Northwest Airlines, Alaska Airlines, and the Brunei Emirates aircraft hangars.

For more Installation Information visit: www.spectrex-inc.com

OVERVIEW
Basically, an aircraft hangar is a large building designed to provide weather protection and workshop facilities for aircraft maintenance and storage. Hangar size and configuration vary widely - some are designed to house one or more specific aircraft, others may house various combinations. In most commercial and military hangars, many engineers and technicians repair service and maintain each aircraft around the clock. Maintenance activities necessarily mean the presence of flammable materials, including aviation fuels, hydraulic fluids, lubricants, cleaning solvents, and paints. As the aircraft is often significantly more valuable than the hangar structure, high performance fire detection and suppression systems for both aircraft and building are either required or highly recommended.

NFPA 409

M

any aircraft hangars have fire protection systems that are in accordance with NFPA 409 Standard on aircraft hangars which provides guidelines for the minimum fire protection. The objective of NFPA 409 is to protect the hangar structure and the people working in it – not the aircraft!

Different insurance groups are responsible for the structure and for underwriting the much more costly aircraft – both in the air and on the ground. NFPA 409 also specifies 90% fire control should be achieved within 30 seconds and 100% within 60 seconds.

3

MILITARY VS. COMMERCIAL HANGAR PROTECTION
he fire protection for military hangars is driven by different fuel and parking restrictions as well as protection of both the aircraft and the structure. The military focus is on aircraft and people first – and structure last. The military developed definitive designs for high bay aircraft hangar facilities where high value military aircraft are maintained and repaired. The US Navy recognized the unique considerations that should be given to protecting vital assets, and identified the installation of a reliable and easily maintained fire protection system, which prevents damage to the aircraft (not directly involved in an initial spill fire ignition scenario) and the hangar structure as a key requirement.

T

FIRE HAZARDS

W

ithin the hangar, aircraft fuel is the major fire risk. An undetected large fuel spill, which if ignited and not detected early, could rapidly engulf an aircraft and the surrounding area. Before the aircraft enters a maintenance hangar, as much fuel as possible is often removed from the fuel tanks to reduce the fire risk. However, many hangars service “other than unfuelled” aircraft, in which case optical flame detection is highly recommended and may be required by local codes e.g. National Fire Code (NFC). Some procedures require the use of highly flammable materials e.g. fuel system leak testing or where personnel enter into the aircraft fuel tank for visual inspection. The risk of accidental fuel leakage or spillage is greatest in the “underwing” area - the shadowed area under the aircraft wings and fuselage. Possible ignition sources include static electricity discharge, electrical systems malfunction and maintenance activities. Some aircraft also utilize fuel tank heaters, which increase the possibility of flammable fuel vapor presence in the area. Other flammable materials such as plastics, electrical insulation, and cleaning materials may be present that could lead to fire propagation. The movement of smoke and heat in high bay aircraft hangars with hangar doors open or closed, along with fire sources from the various fuels, make fire detection difficult and require special fast response, optical flame detectors, capable of rapidly detecting a very small fire source from a long distance. While the worst-case scenario is total loss of the facility and aircraft, even comparatively small aircraft fuel fires, can cause extensive damage to

aircraft wings and fuselages within minutes. It is therefore important to identify the sensitivity and response time required to detect and suppress a fire before extensive aircraft damage occurs. The objectives of the fire protection system are to: • Detect a fire in its incipient stage • Control a fire in the shortest possible time • Minimize damage to aircraft and equipment • Minimize disruption to hangar operations • Minimize the incidence of false alarms Optical flame detectors will provide the fastest detection of an underwing aircraft fuel fire in the early ignition stage. The fast response capability, adjustable field of view, and programmability provided by optical flame detectors make them extremely well suited for monitoring areas where aircraft wings may obscure high risk ignition areas

4

Fig. 1. A typical drawing of hangar coverage by Triple IR detectors.

FIRE HAZARDS

5

within large open areas, with high ceilings and open doors. Protection of aircraft requires optimal detection coverage. Flame detection with high sensitivity and immunity to false alarms, are essential determining factors when designing systems for this application. In the past, adequate detection coverage often required a great number of combined UV/IR detectors. This solution, however, was costly and detectors were subject to false alarms. Point type smoke detectors are not capable of covering the critical shadow areas underneath an aircraft where a fire most likely would occur. As a result, Triple Infrared (IR3) Flame Detectors are now recommended. The IR3 detector has an extended range of vision, allowing the number of detectors covering the same area to be halved compared to UV/IR types and resulting in substantial cost savings. The IR3 detector is extremely sensitive but also has a highly increased ability to distinguish between fire and false alarm sources that can be common within maintenance hangars, and will detect flames in the presence of other common hangar radiant

energy sources such as welding, light sources (incl. Halogen), X-ray inspections and solar blind. The IR3 detector offers two to three times the detection coverage of any solution using conventional IR or UV/IR detectors. Interfaced to a fire alarm system and an automatic fire extinguishing system, these unique detectors will provide optimal detection coverage and the safest and most reliable solution for aircraft protection. SharpEye IR3 Flame Detectors incorporate: • Fast response time • Up to 200 ft (60m) detection distance for gasoline, 150 ft (45m) for JP fuels • Immunity to false alarms from high temperature sources and flickering background radiation • Built-in self-test for the electronics, sensors and window cleanliness. • 3 year warranty / 150,000 hr MTBF With the introduction of the SharpEye Triple IR (IR3) Optical Flame Detector, the aircraft hangar designers are able to meet the military and commercial requirements for reliable fire detection with improved immunity to false alarms and wider coverage of the protected area.

The SharpEye range of optical flame detectors has demonstrated extremely high reliability and immunity to false alarms with an excellent performance record of over 30,000 installations worldwide. SharpEye Flame Detectors have been designed to perform under extreme tough industrial and environmental conditions. The detector provided better and faster response to the fire scenarios (as tested by the US Navy in the dedicated hangar protection project), providing larger area coverage with fewer detectors, thus

lowering the total cost and optimizing the performance of the fire detection system. With the latest development in fire detection from Spectrex, the SharpEye combined CCTV / IR3 Flame Detector, aircraft hangars operators can utilize Closed Circuit Television (CCTV) to improve the ‘out-of-hours’ firefighting response. Detecting a fire at its incipient stage by the infrared sensors and establishing its exact location and size by the color CCTV camera integrated into the detector housing, provides the ultimate 21st century solution to fire protection in aircraft hangars.

LOCATION OF DETECTORS
The number of detectors and their locations in the protected area are determined by: • The size of fire to be detected • The size/dimensions of the protected area • The distance to be detected • The sensitivity of the detectors • The type of flammable materials or expected fuels for a fire that may be present • Detectors’ cone of vision (90° horizontal/vertical) • Obstructions to the lines of sight A dedicated AutoCAD program was developed by Spectrex to provide detailed installation guidelines with detector locations and coverage layout. Aircraft hangars are usually divided into detection zones, in line with the layout of aircraft bays. Typically, up to 4 detectors cover each detection zone. Two are mounted on the wall, about 3.3 ft (1m) above floor level, to monitor underwing areas and two are mounted 50 ft (15m) above floor level. Each detector has a 90° vertical and horizontal cone of vision, ensuring complete coverage of the area. Detectors should be directed towards the middle of the detection zone and have an unobstructed view of the protected area. For added integrity, coincidence detection logic is often used in the control system i.e. at least two detectors, in the same zone, have to be in alarm to actuate the fire-extinguishing system for that zone and the neighboring zone(s). The installation must comply with local/ national standards.

6

Fig. 2. AutoCAD Detectors Layout Example

LIST OF INSTALLATIONS IN AIRCRAFT HANGARS
Extensive evaluation tests conducted by the US Navy, Swedish Air Force and Royal Air Forces (UK) have shown the superior performance of the SharpEye Triple IR (IR3) Flame Detectors.

Military Aircraft Hangars installations include:
• Royal Air Force (RAF) - United Kingdom: Barkstone Heath; Benson; Sealand; St. Leuchars; Wattisham; Wittering • Royal Australian Air Force (RAAF): Amberley, Queensland; East Sale, Victoria; Edinburgh, South Australia; Fairburn Aust Capital; Williamstown, New South Wales • US Air Force (USAF): Bergstrom AFB, Austin, TX; Elison AFB; Holloman AFB, Alamagordo, NM;McCord AFB; Mc Clellan Park; Tyndall AFB;Vandenberg AFB (Shuttle Area & Aircraft Hangar); USAF Academy, Colorado; Malmstrom AFB (USA) • US Dept of Navy: China Lake Naval Air Weapons Station, CA; Oceana Naval Air Station, Norfolk, VA; MCAS, Cherry Point, NC; Whiting Naval Air Station, Pensacola, FL; Ft. Worth Naval Air Station, Fort Worth, TX; Chambers Field Naval Air Station, Norfolk, VA • US Air National Guard: Portland A.N.G. • Japan Air Force: Hamamatsu Airforce Base, Shizuoka, Japan • Key West Naval Air Station - FL, USA • Misawa Airbase - Japan • Swedish Air Force

Commercial Aircraft Hangars installations include:
• AirTran Airlines - Atlanta, GA, USA • Australian Airlines • British Airways - Heathrow and Manchester Airports, UK • Brunei Airlines • CF International - Taiwan • Continental Airlines - Newark International Airport, USA • Gastech - Australia • Iberia Airlines - Spain • Korean Airlines • Lockheed Aeromode Inc. - USA • Northwest Airlines - Columbus, OH, USA • South African Airlines • United Airlines - Indianapolis Airport, USA • Wood Frame Hangar - British Colombia, USA

7

Other SharpEye Flame Detectors applications include:
• Automotive - manufacturing, paint spray booths • Chemical Industry - production, storage, transportation • Explosives & Munitions - handling and storage • Oil & Gas - exploration, production, storage and offloading • Offshore Platforms - fixed rigs and floating vessels FPSO • Onshore - refineries, loading terminals, pipelines • Paint - manufacturing facilities • Petrochemicals - production, storage, shipping facilities • Pharmaceutical Industry • Power Generation Facilities - pump areas, generator rooms, unmanned stations, gas-fired and coal-fired reactors • Printing Industry - solvent handling, presses, drying processes • Tank Farms - floating-roof and fixed-roof tank areas • Warehouses - storage facilities for flammable materials • Waste Disposal Facilities - incineration, processing and storage of flammable waste materials (solids, liquids, gases)

218 Little Falls Road, Cedar Grove, NJ 07009, USA Tel: +1 (973) 239-8398, 1 (800) 452-2107 (Toll free US only), Fax: +1 (973) 239-7614 e-mail: [email protected], website: www.spectrex-inc.com
Specifications subject to changes AN - Aircraft Hangar, June 2006

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close