FAA officials are working on a new airworthiness directive requiring Boeing 787 operators to perform mandatory inspections of the aircraft's Emergency Locator Transmitters (ELT).
The agency issued a statement over the weekend indicating that the soon-to-be mandatory inspections were prompted by a report from the U.K.'s Air Accidents Investigation Branch (AAIB)
, in which the branch suspected that the ELT was the cause of the fire onboard a parked Ethiopian Airlines 787 at Heathrow International Airport recently.
AAIB believes the ELTs, manufactured by Honeywell, contain enough stored energy to initiate a fire, even while the aircraft is not powered up. The ELT is designed to broadcast a signal in the event of a crash to help rescuers locate the downed aircraft. The batteries in the system are separate from the aircraft's electrical power, so that in the event that power is lost, the emergency transmissions would still go through.
"As we noted last week, we support temporarily addressing the ELTs on Boeing 787s as a precautionary measure. The investigation continues and we are not going to speculate on it," a spokesperson for Honeywell said, in an emailed statement to Avionics Magazine.
Boeing also is supportive of AAIB's recommendations to FAA, and is participating in the ongoing investigation of the fire with officials from AAIB, FAA and Honeywell.
FAA does not require the emergency transmitter systems on large commercial aircraft, however the proposed inspections will be mandatory, and operators can expect a final airworthiness directive within several days.
AAIB investigators said there are currently 6,000 ELTs on a wide range of aircraft, and is also recommending inspections of all aircraft (including the 787) that feature the system.