Sensors for Critical Fault Location for Aging Wire Networks

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The National Transportation Safety Board, the Federal Aviation Administration, the Aviation Pilots Association, and the Naval Air Warfare Command have identified aging aircraft wiring as one of the most significant safety issues facing aviation today. Faulty wiring is believed to have caused the TWA Flight 800 and Swiss Air Flight 111 crashes. Dozens of other crashes (commercial and military) have been related to wiring faults as well. NASA, the Nuclear Regulatory Commission, the Consumer Product Safety Commission, the National Train Association, the US Airforce, Army, Navy, and Coast Guard, and the National Science Foundation participated in a joint review of wiring for the White House Commission, identifying it as an area of immediate critical national concern.In spite of the severity of the problem, the technology to inspect the wiring to prevent serious accidents is very limited. Aircraft wiring was meant to last the life span of an aircraft (originally assumed to be 10-15 years) without significant maintenance or inspection, so is "built into" the aircraft body and is extremely difficult to inspect or replace. Commercial aircraft now average 18 years old, and military aircraft average 16 years old. The most common method of inspecting aircraft wiring is visually checking common failure points looking for cracks or breaks the size of the head of a pin. Two other methods -- impedance / continuity testing and Time Domain Reflectometry require connecting/disconnecting wires in order to test them and are suspected of causing more damage than they prevent.