Enhanced Powder Panels for Aircraft Fire Protection: Summary of Recent Validation Testing

Abstract

The 1994 ban on halon production prompted the development of new techniques to replace halon in extinguishing aircraft fires. In 2001, the DoD embarked on an aggressive research and development program, the Next Generation Fire Suppression Technology Program (NGP). The NGP goal was to develop and demonstrate technology for economically feasible, environmentally acceptable and user-safe processes, techniques, and materials that met the operational requirements historically satisfied by halon systems in aircraft. Skyward, Ltd., through the NGP, examined the feasibility of a number of concepts for improving the performance of a fire protection device called a powder panel. Powder panels are thin-walled passive fire protection devices that discharge dry chemical agents under impact to prevent or extinguish combatinduced fires in military vehicles. Different materials, construction techniques, and fire extinguishing powders were examined, and an Enhanced Powder Panel (EPP) design was developed and patented. The Joint Aircraft Survivability Program (JASP) sponsored further efforts to examine the most promising designs in more realistic ballistic live fire testing. Further examination was provided of the potential for these devices to improve aircraft fire protection, while being producible in a practical form and being able to survive a typical aircraft environment. The culmination of EPP development was realized in a Joint Live Fire (JLF) program that validated their effectiveness in production-size dry bays and more realistic configurations. EPP effectiveness was demonstrated in both a helicopter fuselage dry bay at the U.S. Naval Air Warfare Center's China Lake, California facility and a fixed wing leading edge dry bay at the U.S. Air Force 46th Test Wing's Aerospace Vehicle Survivability Facility at Wright-Patterson Air Force Base, Ohio. Testing showed that sustained fires could be prevented in tests involving JP-8 fuel, typical ballistic threats up to and including a 23mm high explosive incendiary threat, and airflow common to in-flight conditions. EPP technology is now being extended to protect flammable fluid lines from ballistically threat-induced fires as well. Environmental testing through Met Laboratories, Inc., is providing additional data to support the EPP as a viable aircraft fire protection method. Recent and on-going test programs, led by the U.S. Air Force 46 Test Wing’s Aerospace Survivability and Safety Flight, have proven the efficacy of EPP protection for dry bays adjacent to fuel tanks and dry bays containing flammable fluid lines. This paper describes how powder panels function, how EPPs improved upon previous technology, and summarizes EPP development from NGP through the current state of EPP technology. With the funding assistance of NGP, JASP and JLF, and the cooperation of the US Air Force and US Navy, EPPs are essentially in final form. In preparation for production integration, application-specific issues are being discussed with potential aircraft customers.