The Air Accidents Investigation Branch released its interim report on the British Airways Boeing 777 crash at London Heathrow on January 17.
EASA said that it and the FAA have agreed that "interim measures in response to Safety Recommendation 2008-047 will be defined through mandatory aircraft level action for the 777 aircraft equipped with Rolls-Royce Trent 800 engines."
The AAIB report said, "The examination of the aircraft has not revealed any pre-existing technical reason for the engine rollback and the subsequent lack of engine response." However, "fuel flow was being restricted, and this restriction continued after the initial engine rollback and through to the ground impact."
The fuel tests were normal, but AAIB said, "The only physical evidence found following the accident was the cavitation marks on the pressure outlet ports of the HP pumps on both engines. From testing and in service experience it is concluded that these marks were fresh, and therefore most probably occurred on this flight, and were caused by a restricted fuel flow, leading to low inlet pressure at the HP pump."
AAIB believes fuel flow was restricted for both engines, probably because of ice in the fuel feed system.