The China Eastern Airbus A330 that suffered from a collapsed engine cowling during take-off from Sydney in 2017 was the fourth such incident to occur since 2006.
The China Eastern Airbus A330 that suffered from a collapsed engine cowling during take-off from Sydney in 2017 was the fourth such incident to occur since 2006.
However, investigators from the Australian Transport Safety Bureau (ATSB) say in a final report that they were unable to conclusively pinpoint the cause, given that the debris had been ingested by the affected powerplant.
The incident took place on the evening of 11 June 2017, when the Rolls-Royce Trent 700-powered A330-200, registered B-6099, took off from Sydney. It was operating flight MU736 to Shanghai and was carrying 238 passengers on board.
About 8min after take-off, the crew reported issues with the left engine and made a request to return to the airport.
Flight data indicated that the left engine pressure ratio began to decrease. The engine’s vibrations also increased with its speed, but continued to provide thrust.
Some 42min after departing the aircraft landed back in Sydney, with some debris from the left engine inlet cowling strewn along the runway and along its return flightpath. No injuries were recorded.
Damage to China Eastern’s A330-200 left engine cowling
ATSB
All of the engine’s fan blades were damaged. Paint and marks found among the blades matched those on the collapsed cowling, investigators state.
As for the engine cowling, investigators found that the inboard upper panel of the cowling had collapsed, with the inboard outer skin panel completely missing.
ATSB investigators note that given that “the majority of the [acoustic] panel was ingested into the engine, there was limited evidence available and this could not be conclusively determined”.
This was despite R-R and Bombardier Aerospace – which manufactured the acoustic panels of the cowling – stating that the most likely cause of the panel failure was because of a “localised disband” between layers.
ATSB adds that with the earlier three Trent 700 incidents, the panels failed at different flight hours and cycles. “Therefore, nil conclusions could be drawn with regard to operational characteristics,” the bureau states.
It notes that R-R had implemented a tap test inspection in the wake of the earlier incidents. Investigators considered if such a move was effective, given that the affected panels were deemed airworthy three months before the incident.
However, the method of inspection had located an adjacent panel’s damage, and that was repaired and intact during the incident, so the ATSB considered the method “likely effective”.
To this end, the ATSB notes that R-R has introduced a number of remedial actions. For one, it has amended its service bulletin relating to inlet acoustic panel inspections. It recommends increasing initial and follow-up inspections, by reducing the interval from two years to one.
Cirium fleets data indicates the aircraft was delivered to China Eastern in 2008, and is still in service with the carrier.
