Total Eclypse for Aircraft Wiring Issues

(Originally published in Defense Industry Daily, 7 Aug 2008.  By DID staff.  See original article here.)

Testing, testing…

Perhaps you’ve had this experience with your car.  A warning light goes on intermittently, or another system doesn’t seem to operate reliably.  The car goes in to the mechanic, where it may or may not display any symptoms.  Repeat as required.  Eventually, the dreaded diagnosis is given: electrical issues.  The problem may or may not be consequential.  The fix will be uncertain.  The experience will be maddening.

For a military pilot and their maintenance crew, electrical issues are inherently more serious – but no less maddening.  Few of us can afford to pay a mechanic for 24 hours of work in order to diagnose an electrical fault, but militaries often do so.  Now consider the long-term effects on wiring from the constant airframe vibrations produced by high-energy turbines, and the buffeting produced by travel at several hundred miles per hour.  Especially in a machine that may be 30 years old or more, while still possessing some of its original wiring.

As military aircraft fleets continue to age, wiring diagnosis and product improvements will be critical.  The F-35 Joint Strike Fighter program is beginning to introduce production innovations involving self-diagnostic wiring, but what about existing aircraft without a full wiring refit? Enter a US NAVAIR project, and a product made by Eclypse International.

The USA’s early 1990’s era Wiring Test Set was having problems.  The electronics industry moves quickly, and some of its parts were becoming hard to find.  In response, the US Air Force and Navy looked ahead, asking for systems that could automate wiring testing and deliver significant improvements to the existing process.

Early in 2008, a winner was declared.  Officials signed a $23.7 million contract with Eclypse International Corporation for its RTS-501 Aircraft Wire Test Sets.

The RTS-501 uses open architecture commercial components to make future parts replacements easier.  More importantly, it offers a quick automated evaluation of the important characteristics of wiring, such as: continuity, isolation, insulation and distance to fault capabilities on all wiring circuits, from simple cables to complex printed circuit boards et.  al.  They units be stacked in a daisy chain to allow up to 128,000 points of switching, and can handle 3,500 continuity tests per minute.

The Navy, Marines Corps and Air Force have subsequently tested this system on aircraft including the E-6 TACAMO command and control airliner, EA-6B Prowler EW aircraft, C-2 Greyhound cargo plane, S-3 Viking sea control aircraft, H-46 Sea Knight helicopter, H-60 Sea Hawk helicopters, H-53 Sea Stallion heavy helicopters, F-15 Eagle fighters, and B-1B Lancer bombers.

How did it do? NAVAIR says:

“In one instance, the analyzer found a mis-wire in the auto-pilot system and a burn-through of a wire in the flight control system that the aircraft’s maintenance team was unaware of.  The analyzer routinely finds troublesome wiring failures even the seasoned maintainer may miss.”

Tom Jordan is 4th Maintenance Group/Air Force Engineering and Technical Services Supervisor at Seymour Johnson Air Force Base:

“Currently we have tested radar wiring on about 88 aircraft…  Of these aircraft, 22 had wiring problems and a number of them had wiring problems that would not have been discovered without using an automated wire analyzer.  Set-up, connection and testing of 480 wires takes about 1 hour with the analyzer and when compared to about 24 hours with an ohm meter.”

The RTS-501’s small size will allow it to be used at an operational level if necessary, something that hasn’t been possible in the past . The US military also plans to use its recording capabilities to collect baseline test data at set intervals for comparison to data fro other systems, and for proactive and reactive testing . The hope is that these efforts will help to identify future trends in wiring systems and repair anomalies.