AL 2003-10
4 December 2003
Metal Spar Wing Wiring Installation
Transport Canada has received a Service Difficulty Report (SDR), from a Bellanca 8GCBC Canadian operator who discovered wing electrical wires utilized for the exterior lights and stall warning system chafed. The exposed wires shorted to ground. Subsequently, the system fuse functioned normally, protecting the circuit. (See photo 1)
Photo 1 - Chafed wires
Improper wire routing and installation was determined to be the cause of the chafing because the electrical wires were secured to the compression struts with masking tape (See photo 2). The operator received these replacement metal spar wing assemblies in this condition from the manufacturer.
The Canadian Bellanca 8GCBC fleet has had fuel tank leaks reported in the past and this problem is progressively being rectified. If the fuel tanks in the aircraft have not been modified, the combination of these two defects can be potentially dangerous.
Photo 2 - Improper wire installation
Transport Canada strongly recommends owners and operators of Bellanca 7 and 8 Series aircraft, that have received wing assemblies from the manufacturer, inspect the wing wiring installation. Failed grommets have also contributed to the chafing of these wires.
Any further defects or occurrences should be reported to Transport Canada, Continuing Airworthiness, Ottawa via the Service Difficulty Reporting program
For further information, contact a Transport Canada Centre, or Mr. Jean Grenier, Continuing Airworthiness, Ottawa, telephone (613) 952-4343, facsimile (613) 996-9178 or e-mail grenije@tc.gc.ca.
For Director, Aircraft Certification
B. Goyaniuk
Chief, Continuing Airworthiness
Note: For the electronic version of this document, please consult the following Web address:
https://tc.canada.ca/en/aviation/aircraft-airworthiness/aircraft-certification