Dreamliner batteries not direct cause of blaze at Heathrow, say investigators The Ethopian Airlines Boeing 787 Dreamliner near terminal 3 at Heathrow airport. Investigators probing the cause of the fire on the Boeing 787 Dreamliner that forced Heathrow airport to close said there was no evidence that its batteries were directly to blame. The fire aboard the Ethiopian Airlines plane broke out on Friday while it was on a remote parking stand, leading to the closure of the airport's runways for 90 minutes. Earlier this year all 50 Dreamliners in service worldwide were grounded after two incidents involving their batteries caused concerns that they could cause a fire. The planes returned to the skies after modifications were made. But an initial report by the Air Accidents Investigation Branch (AAIB) found "there is no evidence of a direct causal relationship" between the batteries and the incident at Heathrow. It found that the fire damage was not near the part of the plane that housed the batteries. The aircraft is currently in a hangar at Heathrow while the investigation continues. It is likely to be several days before the AAIB reaches a more concrete conclusion. It said it had found "extensive heat damage in the upper portion of the rear fuselage, a complex part of the aircraft." 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. Ethiopian Airlines has said it will continue operating its fleet of Dreamliners. It said the plane had been parked for eight hours before smoke was spotted and the incident was "not related to flight safety."