A mid-air explosion in the engine on a Qantas A380 superjumbo has been linked to a component in the engine by maker Rolls-Royce.
Rolls-Royce says it has drawn two key conclusions from the incident last week involving the Trent 900 engine, which is used on Qantas's six A380s.
"First, as previously announced, the issue is specific to the Trent 900," it said in a statement.
"Secondly, the failure was confined to a specific component in the turbine area of the engine."
This had caused an oil fire which affected a turbine disc, it added.
The engine maker's investigations have been under way since Qantas flight QF32 from Singapore to Sydney was forced to turn back when one of its four engines exploded over Indonesia on 4 November.
Qantas quickly suspended all of its A380 services and the aircraft have been grounded for nine days so far.
Rolls-Royce's conclusions so far are in line with those of aviation authorities, the ABC reports.
The European Aviation Safety Authority said on Thursday an oil fire inside the engine on QF32 may have caused the failure of a turbine disc.
"Rolls-Royce continues to work closely with the investigating authorities," it said.
"Our process of inspection will continue and will be supplemented by the replacement of the relevant module according to an agreed program."
Qantas has already said one engine on each of three A380s will be replaced.
Singapore Airlines said on Thursday it also had three single engines on three planes that needed similar attention.
Qantas said this week its A380 aircraft would be out of action until it could be sure they were safe.
