Canadian investigators have disclosed that a Korea-bound Delta Air Lines Airbus A350-900 encountered engine surges and a thrust roll-back before the aircraft diverted to Alaska. The aircraft had been operating the DL159 service from Detroit to Seoul Jan 21. Transportation Safety Board of Canada says the right-hand Rolls-Royce Trent XWB powerplant began experiencing surging which, it says, led to the roll-back and subsequent shutdown. US FAA regulators approved the A350-900 for 300min extended twin-engined operations in 2016. The board says the aircraft landed without further incident, and none of the 189 occupants was injured. But it has not given any indication as to the cause of the surging in the powerplant. <br/>