An AirAsia X flight from Perth in which the pilot urged passengers to say a prayer when the aircraft began to violently shudder, had a serious engine defect that went undetected through no fault of the airline.
The final Australian Transport Safety Bureau report on the incident, which took place on June 25, 2017, examined how the broken fan blade in the engine was missed and why the flight to Kuala Lumpur did not divert to the closest airport, instead of returning to Perth.
The report said the flight crew first became aware there was a problem with the left engine about an hour into the trip when a metallic bang was heard, and “significant vibrations” started through the airframe of the A330.
An engine stall warning was presented, and the crew began a single engine return to Perth after deciding the emergency was not dire enough to divert to Learmonth Airport which was significantly closer.
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The ATSB found the problem with the fan blade was due to the time allowed by engine manufacturer Rolls-Royce between scheduled inspections.
“Although the failed blade had been subjected to inspection, the fatigue crack progressed to failure before its next scheduled inspection,” the report said.
“As such it was found that the inspection interval was too great to capture the crack that developed in this blade before it reached a critical size.”
In response to the investigation and a number of other similar incidents, the ATSB said Rolls-Royce had begun a review of the design and manufacturing of the Trent 700 fan blade.