SYDNEY - Qantas will keep its six A380 superjumbos on the ground for at least the next 72 hours, as testing on their Rolls-Royce engines continues after oil leaks were discovered on three aircraft.
Airline chief executive Alan Joyce said on Monday leaks had been found in the turbine area of three engines, on two planes in Los Angeles and one in Sydney.
"We are now planning that the A380 fleet will remain out of service for at least 72 hours," he told reporters in Sydney.
"We will not be operating the fleet until we're 100 per cent sure that we can ensure the safety of our operations going forward."
Mr Joyce said discovery of the oil leaks had narrowed the investigation into what caused the engine to explode on QF32, a Sydney-bound A380 flight, last Thursday.
One of the aircraft's four Trent 900 engines exploded as it flew over the Indonesia island of Batam, forcing it to return to Singapore.
No one onboard was injured and the 433 passengers have now all arrived in Sydney.
Mr Joyce said teams of Qantas engineers were conducting inspections on the A380s, alongside crews from Airbus and Rolls-Royce.
However, he said investigations into other areas of the engine would continue "in order to rule out other potential issues".
"Those engines have been removed from the aircraft in question and Rolls-Royce are using those engines to test and look for - `could this be the cause of the QF32 incident last week'?"
Mr Joyce said the oil leaks "were beyond normal tolerances".
The affected engines would be replaced by spares, he said.
The A380s each have four engines, and testing by engineers over the weekend involved up to 24 engines on planes grounded in Los Angeles, Sydney and Singapore.
Mr Joyce said the airline has put on additional flights from London, where 30 passengers are stranded, and Los Angeles, where 500 are, to clear the backlog within 24 hours.
He was unable to say what the grounding would cost the airline, which has also had to put displaced passengers up in hotels.
"It's too early to put a number on the total cost to the organisation, we will do that once we have the aircraft back into service," he said.
Asked about possible legal action or compensation against the aircraft and engine makers, Mr Joyce said discussions would take place after the A380s were flying again.
"Our focus is still on making sure we work with Airbus and Rolls-Royce to get the aircraft back into operations and any discussion about compensation will take place after that event," Mr Joyce said.
A day after the A380s were grounded, Qantas suffered another scare when an engine on one of its Boeing 747-400s shut down after exploding.
The plane, which was also on its way to Sydney from Singapore, also turned back to Changi Airport.
Lufthansa, which also operates A380 aircraft with Rolls-Royce engines, told AAP it had no plans to undertake any further inspections of its engines, beyond those it had already carried out on Rolls-Royce's recommendation.
A spokeswoman for Singapore Airlines told AAP the company had completed inspections of all its A380 engines and had not found anything to be concerned about.