• Fire protection measures are necessary for aircraft hangars.airport image by Svetlana Kashkina from Fotolia.com
  
  According to the federal National Fire Protection Association (NFPA), fire-accident protection measures have to be put into place to ensure the safety of aircraft hangars. Regulations, codes and standards governing fire safety in aircraft hangars are documented under NFPA code 409. The code outlines the regulation of fire suppression and safety in aircraft hangars. The use of measures such as foam fire-suppression systems are encouraged to combat fire outbreaks resulting from the presence of hydrocarbon fuels in aircraft hangars.
  
  

About NFPA-409

• NFPA-409 is the federal standard utilized in the design and application of Aqueous Film-Forming Foam systems. These systems are used in most aircraft hangars to suppress fires arising from hydrocarbon fuels. With most federal aircraft hangars being under Group 1, II and III, the NFPA, under regulation code 409, outlines the design and implementation measures for foam fire suppression systems in these aircraft hangars. This applies to both civilian and military aircraft hangars.
  
  

Design

• According to FPA guidelines, aircraft hangars can be designed using criteria that utilize an automated foam water deluge sprinkler system. The discharge rate of the sprinkler system can be adjusted to meet adequate coverage for the floor area of a hangar.
  
  

Combined foam and sprinkler systems

• In line with NFPA-409, a combination of automatic sprinkler protection and an automatic low-level, low-expansion foam system may be utilized in a singular foam fire-suppression system. Similarly, an automatic sprinkler protection may be used alongside a high-expansion foam system to set up a fire-fighting foam mechanism. In other setups authorized under NFPA-409, a closed-head foam water sprinkler may be used as a singular system.
  
  

Foam Water Protection

• In accordance with NFPA-409 and as explained under the Department of the Navy's general guidelines (4-1.5), an aircraft hangar's storage and servicing should be protected using a closed-head, water-only sprinkler system and a low-level, aqueous film-forming foam system. A water sprinkler comprised of a wet-pipe or pre-action sprinkler system can be utilized, subject to prevailing weather conditions.
  
  

Placement of Equipment

• In line with NFPA-409 and Department of the Navy guidelines (4-1.9), foam concentrate tanks and sprinkler control valves should be located in separate rooms away from the hangar service area. Flow valves should be located in a position best facilitating aqueous film-forming foam delivery time to the hangar. Ease of equipment removal should also be considered.
  
  

Heat Systems

• According to NFPA guidelines, when utilizing overhead heat systems, natural gas-fired tube heaters ought to be outlined within the servicing area of the hangar. Caution ought to be taken since heaters with a flame or glowing element within the servicing area may trigger the optical-flame detectors. In addition, environmental safety should also be a primary concern in setting up a foam fire-suppression system in an aircraft hangar.