Qantas Airways says that investigations into the uncontained failure of a Rolls-Royce Trent 900 engine powering one of its Airbus A380s last week have narrowed on an unusual "oil leakage" in the turbine area.

Qantas officials say that the entire intermediate chamber of the engine was lost in the incident, which also led to damage to the left wing's leading edge inboard of the number two powerplant.

The incident occurred six minutes after take-off from Singapore en-route to Sydney, but the pilots safely returned to Singapore.

"The focus of the investigation has been narrowed to the possibility of an oil leakage in the relevant turbine area. However, investigations on other areas of the engine are continuing, in order to rule out other potential issues," says the Oneworld carrier.

"Qantas engineers have removed a number of engines to undertake further examination. Engineers have been investigating the engines in detail and how their components and design perform under operational conditions, as opposed to the original out-of-factory expectations."

Australia's national carrier says that it is continuing an inspection of all of the Rolls-Royce T900 engines that power its A380 fleet. These are taking place in Sydney and Los Angeles, and involve Qantas engineers, as well as staff from Rolls-Royce, Airbus and the Australian regulators.

The carrier says that it will not return its A380 fleet to service until it is confident that the "issues have been identified and resolved". This is likely to take at least another 72 hours, it adds.

Source: Air Transport Intelligence news