Electric Assemblies in Aviation

Airplanes are well known for the complexity of their electro-mechanical assemblies and systems. In fact, to completely wire a Boeing 747 requires over 170 miles of wiring. Because of this incredible volume of wiring, failures can be rather difficult to detect through standard maintenance and quality checking by physical inspection. A team at BAE Systems is currently working on a new project to automate wire and electrical connector testing in the RAF Tornado jet fighter. During a recently completed test program, the team was able to successfully demonstrate the myriad benefits such a system can deliver. Using this new automated system, failures and faults can be easily identified during or after production, and rectified with detailed maintenance or upgrades.

Though not quite as large as a 747, modern fighter jets like the Tornado contain hundreds of miles of wiring that transmit vital information or perform tasks. Within all of these electrical connectors and wiring lies the inevitability of wiring faults or insulation degradation. These failures might be the result of any of a number of factors including aging or corrosion of the wires, operational flying, or can simply be compromised during routine maintenance or modifications to the aircraft.

Not only are these failures potentially hazardous for the pilot and aircraft, but they are also very difficult to detect even with standard testing procedures. In military applications, these aircraft are deconstructed to a large degree in order to perform rigorous maintenance checks between each flight. Typically checklists are carried out manually or via physical inspection by young enlisted service people fresh out of high school. With this new testing harness, any margin for error, human or otherwise, is drastically reduced.

The test sequentially checks every wire and connector pin to make sure it has the correct electrical continuity and insulation resistance. Given that there are over one thousand individual connections that must be tested before the aircraft’s electrical component is granted approval, this would otherwise be a very laborious process. Although the test harness requires three days to install in the aircraft, the test sequence can run in as little as one hour, checking each of over 24,000 different variables.

In order to run the test system, a very large wiring harness must be applied to the aircraft. This test harness is composed of over 154 miles of wiring and contains over one hundred individual circuits to cover the twenty-two electrical systems within the aircraft. Early testing suggests that the automated test will check wires at a rate of 400 per minute.

This is just one of the many applications for wiring and wire harnesses in aviation. Most electrical connector suppliers provide pre-tested electro-mechanical assemblies that are immediately ready for install. However, making sure that all of the thousands of connectors inside today’s modern aircraft are installed and functioning properly is no easy task. With the adoption of dramatic advances in aviation wiring technology like this, aircraft manufacturers are guaranteed to speed up their production lines and reduce costs.

For more information or a free quote on electro-mechanical assemblies from LoDan Electronics today.