Fault arc propagation on aircraft wires under different environmental pressure conditions

Fault ares occurred in damageo wires have been identified as a failure reason for many aircraft accidents. As there are hundreds of kilometers of wiring in a commercial aircraft, the damaged wires are extremely difficult to be detected at aircraft maintenance. Thus more attention on the performance of applied wire insulation in aircraft in the stage of development of the wire insulation is necessary. To cope with the fault type "arc failure" and in order to increase the aircraft safety, various of arc resistance test methods have been developed by different organisations in the last years. But all of them have not taken into account the environmental conditions in an aircraft. Therefore a new test method considering the environmental pressure conditions has been developed. According to this new method, more than 300 fault are tests have-been performed with typical aircraft wire insulations under different environmental conditions. The test results show that the environmental conditions have an important influence on the fault arc behaviour. The detailed test results are presented and discussed in this paper.