U.K. investigators focus on transmitter in Heathrow 787 fire

Though the Boeing 787's lithium-ion batteries have been the cause of previous fires on the aircraft, they do not appear to have been the cause of last week's blaze.

Kent German Former senior managing editor / features
Kent was a senior managing editor at CNET News. A veteran of CNET since 2003, he reviewed the first iPhone and worked in both the London and San Francisco offices. When not working, he's planning his next vacation, walking his dog or watching planes land at the airport (yes, really).
Kent German
2 min read
An Ethiopian Airlines 787 under construction at Boeing's Everett, Wash., plant in June 2011. Kent German/CNET

The Boeing 787's troubled lithium-ion batteries do not appear to have caused a parked Ethiopian Airlines Dreamliner to catch fire at London's Heathrow Airport on Friday.

According to a statement (PDF) from the United Kingdom's Air Accidents Investigation Branch (AAIB), because the damaged area near the tail of the aircraft is far aft from where the batteries powering the Auxiliary Power Unit are located, "there is no evidence of a direct causal relationship" at this stage.

Instead, the Wall Street Journal reported yesterday that investigators are considering a small transmitter made by Honeywell located near the damaged section. Powered by an internal lithium-manganese battery and not unique to the 787, the transmitter is used to help find the aircraft in the event of a crash.

Though a Boeing spokesman confirmed to CNET that the company is assisting the AAIB with the investigation, he said the British agency is responsible for announcing any further findings from the investigation. The AAIB has not released any additional information since its statement on Saturday.

The Heathrow fire comes after the 787 returned to service from a four-month grounding by the Federal Aviation Administration. Two on-board fires attributed to the lithium-ion batteries, which had not been used to power systems on a commercial airliner before, promoted the grounding on January 16.

After Boeing redesigned the charging system and the enclosure for the battery, the FAA returned the 787's airworthiness certificate. Also last Friday, a Florida-bound Thomson Airways 787 was forced to return to Manchester Airport following an unrelated technical issue.

Boeing shows 787 Dreamliner off in Paris (pictures)

See all photos