Feasibility of spread spectrum sensors for location of arcs on live wires

Spread spectrum methods are an important emerging class of sensors that have the potential to locate small, intermittent faults on energized aircraft power circuit wires. Previous work has demonstrated the use of these methods for hard faults (open and short circuits). This paper extends that work to the location of typical intermittent faults that plague aircraft maintainers. Test results on 200-ft-long realistic aircraft wires demonstrate the feasibility of these techniques to locate both wet and dry arcs while the system is powered with 400-Hz 115-V ac power running a variety of aircraft lighting loads. The capability of the system to function with either the aircraft structure or a paired wire as the return path to ground is demonstrated. These results indicate that spread spectrum methods have significant promise for locating intermittent faults on wires as they occur in flight or other modes of operation, such as landing and takeoff, taxiing, and other critical times when possible vibration, etc., may cause intermittent faults.