The accident was investigated by the Air Accidents Investigation Branch (AAIB) and a final report was issued in 2010. Ice crystals in the jet fuel were blamed as the cause of the accident, clogging the fuel/oil heat exchanger (FOHE) of each engine. This restricted fuel flow to the engines when thrust was demanded during the final approach to Heathrow. The AAIB identified this rare problem as specific to Rolls-Royce Trent 800 engine FOHEs. Rolls-Royce developed a modification to the FOHE; the European Aviation Safety Agency (EASA) mandated all affected aircraft to be fitted with the modification before 1 January 2011. The US Federal Aviation Administration noted a similar incident occurring on an Airbus A330 fitted with Rolls-Royce Trent 700 engines and ordered an airworthiness directive to be issued, mandating the redesign of the FOHE in Rolls-Royce Trent 500, 700, and 800 engines.
