The FAA on Friday will publish a directive giving Boeing 787 operators 10 days to inspect Honeywell emergency locator transmitters (ELTs) or remove them from service.
The agency’s airworthiness directive (AD), triggered by the July 12 fire on an Ethiopian Airlines 787 at London Heathrow Airport, orders checks of the ELT, its lithium-manganese-dioxide battery and “associated wiring” for “discrepancies.”
In a statement last week, the FAA said the checks would look for proper wire routing and any signs of wire damage or “pinching,” as well as “unusual” signs of heating or moisture in the ELT battery compartment.
Last week’s statement did not discuss removing ELTs as an option to comply.
Preliminary conclusions in a U.K. Air Accidents Investigation Branch (AAIB)-led probe determined that the fire’s source was most likely a wire short circuit or an issue with the ELT’s battery, though the investigation is continuing.
The AD applies only to in-service aircraft and technically covers only six United Airlines 787s, as the carrier is the only one operating U.S.-registered models, which must comply with FAA ADs. Other authorities are expected to adopt FAA’s directive or a similar order, effectively spreading the mandate worldwide.
Some operators, acting on AAIB’s initial reports, are ahead of regulators.
United has visually inspected its aircraft and reported no findings of problems so far.