Australia's Qantas Airlines said Friday that a faulty part or design issue may have been responsible for a midair engine failure on an Airbus passenger plane.
Qantas chief executive Alan Joyce said it is too early to say exactly what caused the engine failure that prompted an emergency landing Thursday. However, he said it was most likely some kind of material failure or a design flaw in the Rolls-Royce engine.
Rolls-Royce has been maintaining the engines on the A380s, the world's largest passenger plane. But Joyce said he does not believe the problem was in any way related to maintenance.
The Australian airline grounded all six of its Airbus A380s after the engine, one of four on the plane, failed shortly after take-off from Singapore on a flight to Sydney.
The A380 returned to Singapore safely 90 minutes later after the pilot dumped fuel to reduce its weight. Qantas said no one was injured among the 459 passengers and crew on board.
Singapore Airlines also grounded all of its Airbus A380s, but later lifted the order saying it had checked and cleared the fleet of 11 planes.
Passengers on the Qantas flight said they heard an explosion, then saw flames shoot out of the damaged engine.
The plane's manufacturer, France-based Airbus, and Rolls-Royce said they would join air safety investigators from Singapore and elsewhere in determining the cause.
Witnesses in a nearby area of western Indonesia reported hearing a loud noise in the sky and seeing an airliner circling overhead. The head of Indonesia's Transportation Safety Board, Tantang Kurnia, said debris from the aircraft was found on the island of Batam. Some fell onto houses and a shopping mall.
There are about 25 jet engine failures each year, either in flight or on the ground. But the U.S. air safety investigative agency, the National Transportation Safety Board, said the failures rarely cause problems because multi-engine jets are designed to be flown with one inoperative engine. Pilots are trained to fly aircraft after an engine failure.
There are 37 Airbus A380s in operation around the world. The jets can carry up to 853 passengers, although most airlines configure the plane's seating to carry about 550. The jumbo jet is more than 24 meters high and 73 meters long. The plane costs $347 million.
Qantas has never had a fatal crash in its 90-year history.
Some information for this report was provided by AP, AFP and Reuters.