UK Air Accidents Investigation Branch (AAIB) released (19-Jul-2013) a bulletin providing an update on its investigation into an onboard fire of an Ethiopian Airlines 787 while parked at London Heathrow Airport on 12-Jul-2013. The 787 suffered extensive heat damage in upper portion of the rear fuselage. The AAIB stated the damage coincides with the location of the aircraft’s Emergency Locator Transmitter (ELT) and its associated system wiring which is mounted internally on structure close to the aircraft skin. Detailed examination of the ELT showed indications of disruption to the battery cells, although it is unclear whether combustion in the area of the ELT was initiated by a release of energy within the batteries or by an external mechanism such as an electrical short. In response AAIB made the following two safety recommendation:
- That the US FAA initiate action for making inert the Honeywell International RESCU406AFN fixed ELT system in Boeing 787 aircraft until appropriate airworthiness actions can be completed;
- That the US FAA in association with other regulatory authorities, conduct a safety review of installations of lithium-powered ELT systems in other aircraft types and, where appropriate, initiate airworthiness action.
Detailed examination of the ELT and the possible mechanisms for the initiation and sustaining of the fire in this aircraft continues. Further updates on progress will be published as appropriate. [more - original PR]