Electrical wiring didn’t used to be considered a likely source of safety risks among aircraft in the world’s passenger fleets. But a series of fatal airplane crashes in the span of just a few years quickly raised the visibility of wiring-related failures and alerted regulators and the flying public alike to the critical nature of aircraft wiring [1
]. The resultant Electrical Wire Interconnection Systems (EWIS) government safety regulatory mandate [2
] for aircraft electrical systems has added even more complexity on already challenging design and manufacturing processes.
Commercial-off-the-shelf (COTS) software solutions have been developed to manage this complexity and assist in certification efforts. These tools manage electrical wiring systems engineering data through all stages of defining, designing, building, and servicing the aircraft’s electrical systems (Figure 1
Figure 1: Platform-based wiring systems development process
Leading COTS tools for mechanical definition have embraced a platform development process for some time, and a similar transformation is now occurring in the electrical domain. EWIS regulatory demands are causing many OEMs to reevaluate their electrical architecture development processes.
A change made in one system or subsystem of an aircraft design can have tremendous effect on other systems. The old approach that relied on individuals having the knowledge to fix problems isn’t working anymore. Couple increasing technical challenges with the increasing expectation of an OEM’s operating income that depends in large part on reducing non-recurring engineering costs; and as profit margins are getting tighter, the process needs to change.
The challenges of specifying, designing, and building the electrical distribution architecture for aircraft platforms have always been extremely complex. The amount of electronic systems in aircraft continues to increase. At the same time, circuit protection requirements are getting tighter. Regulatory agencies are much more interested in EMC/EMI, lightning effects, HIRF, and other signal crosstalk than they were a couple of decades ago. The increase in signals, the higher frequencies, the lower energy thresholds for the signals, the dependence on signal vs. mechanical systems, etc. make protecting the signals more important [3