Arc Fault Circuit Interrupter Development Overview

Present aircraft circuit breakers do not detect and react to arcing faults. Arcing faults can be caused by many factors such as aging, damaged insulation, wire chafing, wire breakage, and contamination. While initial concerns have focused on Kapton insulation, there remains an across the board concern for aging, damaged, or mis-installed wiring and the FAA, Navy, and other agencies are studying these effects on the aircraft wiring systems. The AFCI circuit breaker project explored the development of an advanced aerospace circuit protection device that incorporated Arc Fault Circuit Interruption capability to mitigate the risk of aircraft fires. The goal of this effort was to develop flyable hardware, with arc fault interruption capability that could be incorporated into a product similar in form factor to an existing MS24571 circuit breaker. The effort resulted in the development of a much smaller MS14105 sized AFCI device that successfully completed over 5,000 operating flight hours in 20 different circuits on three different airplanes.