Showcasing a joint effort between the Navy, the FAA and industry, an FAA 727 stopped here July 2 to allow engineers and program officials to see arc fault circuit breakers in test aboard a commercial aircraft.

Designed to protect military and civilian aircraft from wiring-related mishaps, arc fault circuit breaker technology development is a joint effort between NAVAIR's Aging Aircraft IPT, the FAA and the Office of Naval Research.

The effort currently involves flight-testing the second of two prototype breakers developed under contracts awarded to Eaton Aerospace and Hendry Telephone/Texas Instruments.

The short-notice visit by the FAA's flying test bed, made possible by the support rendered by the station's air operations department, gave NAVAIR engineers a unique opportunity to see testing in progress, according to Chuck Singer of NAVAIR's Electrical Power Systems Division and the lead Navy engineer on the project. The visit also allowed those program officials unfamiliar with the technology to see it actually in use aboard a commercial aircraft.

The first breaker, produced by Eaton, successfully completed 300 hours of flight test aboard a Navy C-9, from Fleet Logistics Squadron 56 in Norfolk, Va., in February with no failures or false trips. The Eaton prototype was also tested aboard the FAA 727.
Following the Eaton breaker evaluation, FAA testing started on the second prototype, produced by Hendry. Navy evaluation of the Hendry breaker is scheduled to start in August.

So far, testing has been very successful, according to Bob Ernst, head of the NAVAIR Aging Aircraft IPT.

"We've met or exceeded every milestone in development," Ernst said. "The program is on cost and on schedule, and performance is excellent. We're on schedule because we built conservatism into the schedule."
That conservatism, according to Ernst, ensures every possible waveform and arc fault detecting algorithm is considered and programmed into the breaker.

"This isn't simple," he explained. "That's why is isn't getting done overnight. The Navy, FAA, Air Force Airline Pilots' Association, NASA and the Society of Automotive Engineers are working together to develop a common specification. It's better to spend a little extra time up front to make sure we get it right.

"If we throw something over the transom to the fleet that has a lot of false trips, the maintainers will just throw it back," he said. "And that won't do anyone any good."

The team isn't qualifying the breakers specifically to military and FAA specs, according to Singer. The team, in collaboration with the SAE, is writing a commercial specification for COTS equipment with room for military requirements. That way, each platform won't have to individually qualify the breakers.

"The specification is 95 percent done," Singer said. "And it should be before the SAE [Protection System Committee] in October for approval."

Once that's complete, said Ernst, the production of the first family of arc fault breakers (for commercial aircraft and their military derivatives) will go into production in earnest.

"In FY03, we'll be able to start ordering," Ernst said. "We're asking programs to POM funding for FY04 for procurement."

Meanwhile, according to Singer, the second developmental contract to miniaturize the technology for use in tactical aircraft and helicopters - a joint contract with the Air Force - should be awarded in August.

CUTLINES

Sillouette.jpg - NAVAIR engineers and program officials board the FAA's 727 flying test bed July 2 for a briefing on arc fault circuit breaker technology testing. The joint developmental program, comprised of the Navy, the FAA and industry, is developing circuit breaker technology to protect aircraft from catastrophic wiring mishaps.

Console.jpg - Catching a wave - Mike Peppas, qualification team lead for the NAVAIR qualifying activity for electrical distribution components (AIR 4.4.4) looks at electrical waveforms being "watched" by arc fault circuit breakers onboard the FAA's 727 flying test bed. Briefing him is Rich Gleich, an engineer with the FAA.