An initial investigation into what caused a parked Ethiopian 787 Dreamliner to catch fire Friday at Heathrow Airport in London is not linked to the aircraft's redesigned lithium-ion battery system, according to the U.K. Air Accidents Investigation Branch (AAIB).
The fire occurred Friday while the aircraft was parked on a remote parking stand with no passengers onboard, and temporarily shut down both runways at Heathrow.
"There has been extensive heat damage in the upper portion of the rear fuselage, a complex part of the aircraft, and the initial investigation is likely to take several days," AAIB said in a statement. "However, it is clear that this heat damage is remote from the area in which the aircraft main and APU (Auxiliary Power Unit) batteries are located, and, at this stage, there is no evidence of a direct causal relationship."
While the cause of the fire is still under investigation, AAIB's initial report is significant, as the overheating of the lithium-ion battery system lead to the grounding of the worldwide fleet of 787s in January. Boeing
redesigned the system, and 787s were re-entered into service in April.
Ethiopian Airlines was the first carrier to return its 787s to service following the grounding.
AAIB is joined by Boeing
, the National Transportation Safety Board (NTSB), U.K.'s Civil Aviation Authority (CAA), Ethiopia's CAA and Ethiopian Airlines in the ongoing investigation.
Related: Ethiopian Airlines Boeing 787 Fire Closes Heathrow Runways