Final report

Summary

What happened

On 6 May 2014, an Airbus A330 aircraft, operated by Vietnam Airlines and powered by Pratt and Whitney PW4168A engines, was conducting a regular passenger service from Melbourne, Victoria to Ho Chi Minh City, Vietnam. During the take-off roll, the crew received indications that the right engine had failed. The flight crew responded by discontinuing the take‑off. There were no injuries to passengers or crew.

Examination of the right engine determined that it had sustained an uncontained failure of the stage four low‑pressure turbine. Fragments of the turbine exited the engine via perforations in the low-pressure turbine front case but were retained within the engine cowls. Turbine debris exiting the exhaust duct damaged the right inboard and outboard flaps, flap fairings and a spoiler.

What the ATSB found

The ATSB found that the engine failed due to high-cycle fatigue cracking and the fracture of a single stage four low-pressure turbine blade. Release of the fractured blade resulted in the subsequent failure of the turbine. The fatigue crack initiation point on the remaining blade stub of the fractured blade was obscured by damage from rotational contact that occurred during the engine failure sequence. This prevented the ATSB from determining whether any pre-existing material anomaly or damage contributed to the crack initiation.

No similar failures in Pratt and Whitney PW4168A engines were identified.

The ATSB found the flight crew’s handling of the rejected take-off reduced the risk of a runway excursion, preventing further damage to the aircraft or injury to passengers or crew.

Safety message

Although in this case the cause of the turbine blade failure could not be identified, this occurrence highlights the benefits of timely and appropriate flight crew action in response to an unexpected engine failure on take-off.

PW4168A engine S/N P733510
PW4168A engine S/N P733510Source: United States National Transportation Safety BoardPW4168A engine S/N P733510Source: United States National Transportation Safety BoardSource: United States National Transportation Safety Board

 

The occurrence

Context

Safety analysis

Findings

Sources and submissions