Boeing has asked airlines around the world to inspect Honeywell emergency locator transmitters (ELTs) fitted on over 1,000 aircraft ahead of possible action by airworthiness authorities to address a potential fire risk in the beacons.

Boeing says that it is asking "specific operators" of Boeing 717s, 737NGs, 747-400s, 767s and 777s to inspect aircraft fitted with Honeywell ELTs and gather data to support potential regulatory action by the US Federal Aviation Administration (FAA).

"Up to 1,200 aircraft have been fitted with the devices, but we are asking that airlines inspect as many as possible and report back within 10 days to help regulators decide what, if any, action to take," says a Boeing spokesman.

Boeing's request comes after an AAIB special bulletin that was issued in relation to its investigation into the fire on board an Ethiopian Airlines 787-8 that was parked at London Heathrow on 12 July.

As one of the safety recommendations in that bulletin, it has called on the FAA and other airworithness authorities to "conduct a safety review of installations of Lithium-powered Emergency Locator Transmitter systems in other aircraft types and, where appropriate, initiate airworthiness action."

The investigation is pointing towards the Honeywell Rescu406AFN transmitter fitted to the 787 as the possible cause of the fire, and the AAIB also recommended that the beacons fitted to other 787s be removed or made inert until further airworthiness actions can be taken.

The AAIB is investigating if a pinched wire between the ELT and its lithium battery may have ignited the fire in the rear of the 787.

United Airlines and All Nippon Airways have found damaged wiring on some ELTs recently removed from their 787s, and have shipped the units to Honeywell for further inspection.

More than 6,000 Rescu406 ELTs have been delivered by Honeywell since it was certificated by the FAA in 2005.

Source: Air Transport Intelligence news