The engine failure that forced a Qantas Airbus A380 to make an emergency landing was "probably" caused by a material failure or a design fault, the Australian airline said today.
Qantas chief executive officer Alan Joyce said: "We believe this is probably most likely a material failure or some type of design issue. We don't believe this is related to maintenance in any way."
The airline today said the superjumbo was carrying 440 passengers and 26 crew when one of its its Rolls-Royce Trent 900 engines burst into flames shortly after departing from Singapore's Changi airport.
British firm Rolls-Royce was today at the centre of an aviation safety probe, after Qantas grounded all six of its A380 planes, which are fitted with the British-made engines.
Mr Joyce told a news conference in Sydney: "This is an engine issue and the engines have been maintained by Rolls-Royce since they were installed on the aircraft."
The announcement came after it was revealed that the European Aviation Safety Authority (EASA) issued an airworthiness directive on August 4 this year concerning potential problems with the powerful Trent 900 engines.
The directive said that "wear beyond engine manual limits could lead to loss of engine performance with potential for in-flight shut down".
Yesterday's incident happened just after flight QF32 had taken off from Singapore to Sydney on the last leg of the flight from London.
One passenger, Singapore-based businessman Ulf Waschbusch, said: "About five minutes after take off from Singapore I heard a loud boom noise on my left hand side so I immediately look out of the window at that point.
"I saw pieces of the engine, number 3 engine, fly off the wing through the wings itself and short bursts of flames for about a second or two at that time.
"It was one of the scariest things I have ever seen on an aircraft."
Plane manufacture Airbus has joined Qantas, as well as Australian and European air safety bodies in an investigation into the incident which is being led by authorities in Singapore.
It was the most serious mid-air incident involving the double-decker A380 since it debuted in October 2007 with a Singapore Airlines flight to Sydney.
Mr Joyce said Qantas, Rolls-Royce and the plane's manufacturer, Airbus, would conduct a series of checks on every engine on the airline's A380s.
Those checks will be finished within 24 to 48 hours, and if no problems are found the planes would resume flying, Mr Joyce said.
Singapore Airlines, which also grounded its A380s after the Qantas incident, said in a statement today it had resumed flights of its superjumbos after having completed precautionary checks that were recommended by Rolls-Royce and Airbus.
Passengers on board the stricken superjumbo were put on a relief flight bound for Australia this morning.
Air traveller Lars Sandberg, a DJ from Glasgow, said he was "just happy to be alive" following the incident.