Fire Extinguishing Agent Evaluation in the Aircraft Engine Nacelle Fire Test Simulator

Abstract : Fire tests and extinguishant concentration tests were conducted using a simulated portion of the F-16 aircraft engine compartment in the Aircraft Engine Nacelle Fire Test Simulator (AENFTS) at Wright-Patterson Air Force Base. Engine compartment ventilation airflow pressure and temperature were varied to simulate a variation in altitude and ram air pressure. Combat damage simulation included inflow with ambient temperature, simulating outer compartment wall penetration and inflow at elevated temperature simulating fan case perforation or engine bleed air line damage. The length of time between ignition and agent release was found critical, particularly when ventilation air pressure greater than sea level ambient was simulated. The existing Halon 1301 specifications were found to be adequate but a revision is proposed to encourage actual agent release tests with high realism for all planned flight conditions, discourage the use of Halon 1202 and include survivability/vulnerability considerations. Keywords: Engine compartment fire extinguishant, Ventilation airflow, Agent distribution, Agent concentration, Halon 1202, Aircraft fires, Halon 1301, Combat damage, Aircraft engine nacelles.