787 Dreamliner fire caused extensive damage to panel

SEATTLE – The Boeing 787 Dreamliner test plane in Tuesday’s in-flight fire suffered substantial damage to one of two main power distribution panels inside the rear electrical equipment bay, Boeing photos show.

An engineering document describes “extensive smoke, fire and structural damage exist to the P100” electrical panel, which is the panel that takes power from the left engine’s generator and distributes it through the airplane to power vital systems.

The P100 panel, about 3.5 feet tall, is located about a foot below the passenger floor just behind the airplane’s wing. Inside the panel is a collection of separate electrical boxes, including control units, circuit breakers and relays.

The official engineering photos, obtained by the Seattle Times, show the fire damage centered at two boxes called contactors low down on the panel. The contactors open circuits or close them as the power needs of airplane systems fluctuate.

Two contactors in the panel were severely damaged by the fire. One “caught fire and melted,” according to the engineering document. The other had “extensive fire and smoke damage to backside.”

Smoke residue and soot permeates the internal surface of the panel, and the back of the panel “has extensive structural damage.”

A Boeing spokeswoman did not dispute the documents’ authenticity.

The engineering document states that before the 787 flies again, mechanics must disassemble the P100 panel “to gain access to further document extent of damage” and document the damage “to each component … (and) to composite fuselage where there were contacts with molten aluminum, burn marks and potential heat damage.”

Scott Fancher, the head of the 787 program, said Wednesday that his team will take as long as it takes “to do it right.”