Boeing investigating if foreign object caused 787 electrical fire

Boeing investigators are looking into a theory the in-flight electrical fire two weeks ago that has grounded the 787 Dreamliner test fleet may have been caused by material a worker inadvertently left inside the electrical panel, according to an executive with a French supplier.

Boeing has ordered inspections of all electrical-power panels on the 30 Dreamliners already built or partially assembled to ensure no "foreign objects" have been overlooked, according to a source close to the 787 program.

If that's the cause, it could be good news for Boeing, since it implies the fire started due to human carelessness rather than a design flaw.

However, even if "foreign object debris" can explain how the fire started, Boeing won't be off the hook. Questions remain about how backup systems kicked in after power was lost from the electrical panel.

That could lead to stiffening of certification requirements that would delay the program further.

Tuesday in Paris, Olivier Zarrouati, chief executive of French supplier Zodiac Aerospace, told analysts a loose object could have caused the fire Nov. 9. Zodiac makes components for the panel where the fire started.

"It is fairly reassuring if it was indeed a question of foreign-object damage," Zarrouati said, as reported by Reuters.

He added he saw no reason for Boeing to order a strong slowdown in production.

Stray tool?

Earlier in the week, French newspaper La Tribune cited sources within Zodiac saying the "foreign object" was a stray tool left behind by a mechanic that somehow caused a short circuit.

However, Boeing photos obtained by The Seattle Times of the damage taken after the plane landed in Texas show no evidence of any tool inside the electrical panel.

A Boeing insider familiar with the flight-test program said the electrical panels are looked at routinely.

The person expressed skepticism about the foreign-object theory, saying, "I can't imagine anything being there that wasn't supposed to be in there."

Whatever the cause of the fire, the serious systems failures that ensued are also a big cause for concern.

A person familiar with the incident said the main flight displays of both the pilot and the co-pilot went blank as a result of the power failure. The display defaulted to another screen between the two pilots.

Also indicating a serious power failure, a small generator called a Ram Air Turbine automatically deployed. This small turbine drops from the fuselage in an emergency and provides power from the passing air flow.

FAA "special condition"

The Federal Aviation Administration in 2008 issued a "special condition" for certification of the 787 that requires Boeing to prove the airplane can fly safely and land even with the two main engines and the auxiliary power unit in the tail inoperative.

However, the regulation states the level of proof required can be relaxed — one needn't assume total and irrecoverable loss of both engines for example — provided Boeing shows "unrecoverable loss of critical portions of the electrical system is extremely improbable."

If something that was thought "extremely improbable" turns out to have actually happened on that flight, then the bar for certification would be raised much higher, possibly requiring a redesign of the electrical system.

Last week, Morgan Stanley analyst Heidi Wood said a redesign of electrical-system software and hardware is likely necessary and "could push first delivery to 2012."

Kenneth Herbert, an analyst with Wedbush Securities who remains bullish on Boeing stock, said in a note to investors Monday "a seventh delay in the first 787 delivery is now all but assured."

Herbert said the first delivery will likely slip to at least June and possibly to the end of the year.

Dominic Gates: 206-464-2963 or dgates@seattletimes.com