Description

On 26 November 2008, a Boeing 777-200 powered by Rolls Royce RB211 Trent 800 series engines and being operated by Delta Air Lines on a scheduled passenger flight from Shanghai Pudong to Atlanta was in the cruise at FL390 in day Visual Meteorological Conditions (VMC) in the vicinity of Bozeman MT when there was an uncommanded thrust reduction or ‘rollback’ of the right engine. Prescribed drills were followed and a descent to FL310 was made after which normal thrust control was regained and the flight continued to the planned destination. None of the 263 occupants were injured.

Investigation

An investigation was carried out by the National Transportation Safety Board (USA) (NTSB) who were already aware of progress in the UK AAIB investigation of the British Airways Boeing 777 thrust loss accident at London Heathrow earlier in 2008 and of the similar engines fitted. Flight Data Recorder (FDR) data was available but Cockpit Voice Recorder (CVR) data had been overwritten.