U.S. ARMY AVIATION HALON REPLACEMENT PROGRAM FOR ROTORCRAFT ENGINE NACELLE FIRE PROTECTION

Halon 1301 is the fire-extinguishing agent currently used by the U.S. Army for rotorcraft engine nacelle fire protection. In September of 2001, the U.S. Army in conjunction with the 46th Test Wing at Wright Patterson Air Force Base (WPAFB) developed a test program for the replacement of Halon in all Army rotorcraft engine nacelle applications. This program included building simulators at WPAFB for each aircraft engine nacelle, building and extinguishing fires, measuring agent concentrations in each of these simulators, and designing an optimized distribution system to deliver the selected agent in each engine nacelle. During the first two phases of testing, many alternate agents and advanced technologies were evaluated. Ultimately, HFC-125 was selected as a common agent for all Army aviation. Phase III efforts completed to date include determining concentration requirements for HFC-125 and optimizing a distribution system for the RAH-66 Comanche engine nacelle. Currently, an engine nacelle simulator for the AH-64 Apache is being constructed at WPAFB.