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Author
Desmarais, L. A. | Tolle, F. F.
Title
Integrated Aircraft Fuel Tank Inerting and Compartment Fire Suppression System. Volume 2. Evaluation of Nitrogen-Enriched Air as a Fire Suppressant. Final Report. August 1979-October 1982.
Coporate
Boeing Military Airplane Co., Seattle, WA
Sponsor
Aero Propulsion Lab., Wright-Patterson AFB, OH
Report
AFAPL-TR-83-2021, Volume 2, April 1983, 227 p.
Contract
F33615-79-C-2027
Keywords
aircraft fuel tanks | carbon dioxide | halon 1301 | inerting | compartment fires | fire suppression | liquid nitrogen | fire extinguishing agents
Identifiers
fire extinguishing agents
Abstract
Aircraft onboard generation of nitrogen-enriched air (NEA) for fuel tank inerting offers significant advantages over the stored nitrogen concept currently in use. Additionally, the excess NEA generated in flight offers a potential fire extinguishing agent. To evaluate this potential, a small scale test appratus was designed based on a survey of actual aircraft fires. Two configurations were used to simulate fires dominated by either forced convection or free convection. The fire types investigated were pool, spray, hot surface and combat damage. Test variables included air temperature, fuel type fuel flow rate and surface temperature. Prior to developing conclusions on th effectiveness of NEA, verification tests were run on othe common extinguishing agents (CO2, LN2, and Halon 1301). The quantity of agents required corresponded well with accepted levels based on previous tests. Several important findings were made. The data, presented in terms of volume percentage (air + extinguishant flow) of extinguishing agent required for fire knock-down, indicates the hot surface fire type to be the most severe. A volume concentration of 72 percent NEA9 (9 percent oxygen by volume) was found to be effective in knocking down the hot surface fire. The test data confirms that NEA is a viable fire extinguishing agent.