British authorities probing a fire onboard a parked Boeing Dreamliner at London’s Heathrow airport recommended on Thursday that Honeywell distress beacons on all 787 planes be deactivated pending further checks.
The Air Accidents Investigation Branch said it was not clear, however, whether the fire originated in the transmitter batteries or was caused by an “external mechanism such as an electrical short”.
The blaze on an Ethiopian Airlines plane in London last Friday was a further blow to Boeing, which withdrew from service its entire fleet of Dreamliners earlier this year due to separate concerns that lithium ion batteries on board could cause fires.
Investigators probing the incident on the plane — which was parked and empty when it happened — have said it was not caused by overheating batteries this time.
“In its preliminary report, the AAIB is expected to put forward two recommendations to the FAA (US aviation safety watchdog), including that the ELT (Emergency Locator Transmitter) be uninstalled to check,” a source close to the case said earlier on Thursday.
It is unclear what the implications would be, and whether this would force the grounding of Dreamliners again.
The AAIB, which refused to comment on Thursday, was also due to ask the FAA to check on all Honeywell beacons of the same type as those on the fire-hit Dreamliner, which are also used on other planes, the source said.
The device is designed to help localise the plane if it crashes, and it is powered by a small lithium-manganese battery.
Investigators are seeking to determine whether the beacon itself caused the fire on the plane or whether its surroundings triggered the incident.
Other planes, including those belonging to Boeing’s rival Airbus, have the same type of distress beacons on board, but these are located in different parts of the aircraft.
Honeywell Aerospace, which has sent experts to Heathrow airport, said Monday that they were never made aware “of any problem on this product”, certified by the FAA since 2005.
On Thursday, it said it had not received any orders to temporarily remove the ELTs from Dreamliners.
But “as a safety-first company, we would support an action like this as a precautionary measure if our team, or the AAIB and NTSB (US National Transportation Safety Board), determine it’s necessary to do so,” spokesman Steve Brecken told AFP.
The Dreamliner, which makes extensive use of lighter, carbon-based composite materials that reduce fuel consumption, came into service in September 2011.
Remove Honeywell beacons from Dreamliners, says probe
