As investigators rule out the 787’s lithium-ion batteries as the cause of last Friday’s fire at London’s Heathrow Airport, their attention has shifted to the plane’s emergency transmitter.

787 on Fire 1024x807 787 fire investigation shifts to emergency transmitter

Investigators looking into the fire that damaged an Ethiopian Airlines Boeing 787 parked at London’s Heathrow Airport have shifted their attention to the emergency locator beacon, according to reports.

As The Wall Street Journal reports, investigators from the U.K. Air Accidents Investigation Branch have taken interest in the lithium-manganese battery that powers the plane’s emergency transmitter. Lithium-manganese batteries are known to be less volatile than the lithium-ion batteries found in the plane’s Auxiliary Power Unit, which were the cause of the fires on board the 787 that led to its grounding earlier this year.

It isn’t yet clear whether the transmitter’s batteries would have started the fire, or would have been an accelerant.

Honeywell, which manufacturers the transmitter, said in a statement to the press that since the particular model was introduced in 2005 they have not seen or experienced a “single reported issue” with the device.

In a report from The New York Times, All Nippon Airways and Japan Airlines, which both operate sizeable fleets of 787s, said that they have completed emergency checks of their aircraft and have found nothing amiss.

All Nippon reported that no signs of charring and other abnormalities on the transmitter when it was inspected.

Source: Wall Street Journal, New York Times