Flight D7237 departed for Kuala Lumpur on Sunday morning with 359 people on board and was about 90 minutes into the flight when the Airbus A330 aircraft experienced problems.
The Australian Transport Safety Bureau (ATSB) has begun investigating the incident. It said in a statement that as a result of an in‑flight engine fault, the aircraft was subjected to moderate airframe vibration and that the flight crew “elected to return to Perth”.
“The ATSB will interview personnel involved and gather additional information. A report will be released within several months,” it added.
The ATSB will also investigate why the plane did not divert to nearby Learmonth, 25 minutes away, instead of returning to Perth, 90 minutes away.
AirAsia has said it had started conducting an investigation, together with its engine manufacturer Rolls-Royce. It is also cooperating with the ATSB probe.
It said in a statement: “AirAsia Group has always strictly followed the maintenance programme prescribed by our manufacturers. In Australia, AirAsia Group has regularly passed safety and security audits conducted by the local aviation authorities.”
Meanwhile, a former Airbus A330 check and training captain told Perthnow that the AirAsia X plane could have lost an entire engine.
The unnamed captain was quoted as saying: “When an engine has severe vibrations it must be shut down immediately as the damage that can be inflicted is immense.
“The engine can detach from the wing, which could be catastrophic. Fuel lines (could be) ripped open and electrics severely damaged or degraded.
“It must be treated like an engine fire. And if after shutdown, it is free-wheeling with a missing blade and the severe vibrations continue you must divert to the nearest suitable airport.”
One passenger was reported as saying the plane was “shaking like a washing machine”.
Saying AirAsia X had released few details of the incident, Perthnow said it understood that the problem involved the failure of a fan blade in the No1 engine.
Perthnow reported that this destroyed the hydraulic components and an oil pump before being ingested by the engine.
Perthnow quoted an “engine expert” as saying it was possible an out-of-balance fan could windmill after the engine was shut down and still cause a low-frequency vibration.
He said it was “a pretty massive failure” and there would be only two reasons for it: a manufacturing flaw or poor quality inspection during maintenance.
AirAsia plane ‘shaking like washing machine’ returns to Australia