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Aging wiring has been identified as a national concern. This paper identifies why wiring installed on legacy aircraft has taken center stage and suggests a planned maintenance approach to enhance wiring safety, improve electronic system performance and reliability. The industry must be encouraged into an awareness of the criticality of electronic systems health. The industry must also become cognizant of the technical and operational issues that govern electronic systems reliability. Several alternatives for improving avionics systems performance will be discussed. With proper training and the common usage of advanced diagnostic/prognostic/verification NDT tooling and repair procedures many of the wiring problems will become non-issues. As the technology issues are understood so too will the frre and wire event safety issues [l]. U.S. Government work not protected by U.S. Copyright 12.D.1-1 and avionics circuits. This measures the true health of the system [7]. systems performance and stability information including LRULRM hctional circuit charts, diagrams and electrical performance trends and prognostics would greatly assist him in the performance of his duties. The value of this is in the ability to anticbate failure of flight critical and flight essential systems and a reduction in accident rates by preventing any system failure from taking place that could become a contributing factor in an accident.

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Aging wiring has been identified as a national concern and is a major topic for those involved in aerospace electrical systems. This paper identifies some of the major contributions why wiring installed on legacv aircraft has taken center stage. It suggests a planned approach to enhance wiring safety that will improve electronic system performance and reliability [ 11. We suggest a two pronged approach:1. Become cognizant of the technical and operational issues that govern electronic systems robustness and determination of useful life. This is accomplished by providing training to those individuals directly exposed to the aircraft electrical systems during operations. Training can aid management, engineering and technical positions by providing the latest practices that are applicable to the tasks at hand. 2. Apply available technology complementary to the issues of legacy and new design aircraft for systems level diagnostics, prognostics and enhanced life expectancy [2].Several alternatives in obtaining both of these objectives will be presented in this document and is only meant to stimulate the thinking of those readers involved in the everyday operations of aircraft into a more proactive approach to maintaining aircraft electrical systems.According to an FAA study conducted in 1998 " current maintenance practices do not adequately address wiring components (wire, wire bundles, connectors, clamps, ground, shielding;) or their effect on electronic systems. Inspection criteria are too general. Typically a zonal inspection task card for wiring states: "Perform a general inspection". Important details pertaining to unacceptable conditions are lacking. Airlines report shortcomings in the manufacture maintenance and repair manual on wire. The current arrangement of standard practices makes it difJicult for an aircraft maintenance technician to locate and extract the pertinate and applicable data necessary to effect a satisfactory repair. Wire replacement is not adequate. Under current maintenance philosophy wire in conduit is not inspected. Onsite inspection and reporting indicate many examples of improper installation and repair of wiring. A review of incidence reports and maintenance records indicate that current reporting systems lack visibilify for wire making it digicult to identifi wire failures. These diflculties development and use of non-destructive test (NDT tools to assess the state of wiring in aircrajk '' can be overcome by