The Problem

The problem to be addressed by the SAFEWIRE project is that of the inspection of complex aircraft wiring bundles. There are many kilometers of wiring in a modern aircraft (~600 km in a Airbus 380), carrying a range of services from vital avionics and communication systems through to in-flight entertainment. It is extremely difficult to inspect these wires during routine maintenance because a) it is bundled into complex harnesses (See the slideshow) and b) it passes behind structural components/bulkheads.

As the wiring ages, the wires themselves and their insulation are subject to a variety of degradation. Failure of a wire or of its insulation can have disastrous consequences, in particular the loss of vital controls or communications or the possibility of fire caused by arcing. A study of international aviation incidents from 1972 to 2000 found 400 to be wiring related.

Damaged wire on space shuttle

Fig.1.2 Damaged wire on Space Shuttle Columbia

A tragic example was TWA Flight 800, a Boeing 747-131, which crashed en route from JFK to Paris CdeG in July 1996 killing all 230 people on board. The National Transportation Safety Board concluded that the most likely cause of the accident was explosion of a fuel tank due to faulty wiring.

A further example was the Swissair Flight 111 disaster in September 1998, in which 229 people died. This was attributed to a failure in the entertainment system wiring.

A Space Shuttle Columbia main engine controller wire short-circuited. Post-flight inspection revealed arcing damage to the wire (see Fig.1.2).

The project consortium has proposed to develop a Non-Destructive Testing (NDT) system which will enable the aircraft wiring to be inspected remotely, thus overcoming the problems discussed above.