The as yet unknown cause of a fire in an Ethiopian 787 parked at London Heathrow airport today and the damage done to a critical part of its plastic fuselage have put Boeing Dreamliners back under scrutiny.
There was no-one on board the jet when the fire was noticed. It has broken out in a very sensitive area of the jet, either burning right through the crown of fuselage forward of the root of the tail structure housing the vertical stabiliser, or causing serious melting and partial combustion of the visible outer layers of the laminate.
It is less than three months since Ethiopian became the first 787 user to return the high composite airliner to service after it had been grounded in January following fires or meltdown in the heavy duty lithium ion batteries in a parked Japan Airlines 787 at Boston, and in an All Nippon Airways 787 that made an emergency landing and evacuation during a domestic flight.
This close up screen grab from Sky News shows the fire has burned through the skin of the Ethiopian jet, leaving the internal framework visible.
A more general view is shown here in a BBC News screen grab.
The damaged area coincides closely with the location of a crew rest area in the ceiling of the rear cabin for some 787 operators, but Ethiopian didn't fit that option to their Dreamliners.
Among the detailed news reports is this mobile app version of the New York Times
story, and a 'Dreamliner 787 catches fire' report in the Wall Street Journal
The cause of the fires that lead to the prolonged grounding the Dreamliners earlier this year was never determined, but Boeing successfully lobbied the US safety regulator, the FAA, to allow the jets to resume services with a 'super fire box' that isolated the lithium ion batteries, located under the cockpit and under the forward section of ther rear cabin near the trailing edge of the wing.
According to Boeing, these boxes would allow the lithium ion batteries to burn out in complete safety and not contaminate the cabin of the jets with noxious fumes.
However the cause of the fire at London Heathrow airport is unknown.
Nor is the cause known of a technical fault that recently grounded an Ethiopian jet at Beijing Airport, other than that it was repaired in some way prior to continuing service after a delay said to have lasted several days.
No definitive statement has yet been issued by Boeing, Ethiopian, the FAA or its UK counterpart. The Financial Times has reported an Ethiopian Airlines source as saying a problem had been found in the air-conditioning system eight hours earlier and that 'sparks' had been observed. That report has not been verified, and lacks detail.
Even if the cause of the fire is unrelated to the aircraft's electrical system the repairability of the burn through area in the fuselage will be of strong interest to current and intended 787 operators and safety authorities.
The 787 is of considerable importance to the business plans of Qantas, Jetstar and Air New Zealand, and is planned to be flown before the end of the year to Australia by Air-India, and possibly Qatar Airways, with China Southern recently flagging a service to Auckland by December.
Jetstar's first 787 is due for delivery in September.