SYDNEY (AP) - Investigators of last week's engine explosion on a Qantas superjumbo focused their search Sunday on a missing piece of turbine from the Rolls-Royce engine, and the airline said it hoped to have its grounded fleet of A380s back in service within days.
The Australian Transport Safety Bureau, which is leading an international investigation into the blowout on the world's newest and largest airliner, appealed for help from residents of Indonesia's Batam island to find the missing chunk of a turbine disc.
The island was scattered with debris last Thursday when one of the A380's four Trent 900 engines failed minutes into a flight to Sydney, with 466 people aboard. The engine was quickly shut down and the plane returned to Singapore and safely made an emergency landing.
"The recovery of that disk could be crucial to a full understanding of the nature of the engine failure, and may have implications for the prevention of future similar occurrences," the bureau said in a statement.
It released a photograph to media of a jagged and bent piece of turbine disc from the Trent 900 engine and asked that anyone who might have found a similar piece should hand it to police.
Qantas CEO Alan Joyce has blamed the blowout on a mechanical or design fault in the engine, not maintenance. Experts said the shattered turbine could indicate the failure point.
Qantas, Australia's national carrier, grounded its six double-decker A380s and began rigorous safety checks. Lufthansa and Singapore Airlines, the other airlines that fly A380s fitted with Trent 900 engines, also briefly grounded their planes last week but resumed services after completing checks.
Joyce told reporters on Saturday that each engine on its A380s would undergo eight hours of tests, and no plane would fly until all checks - being undertaken in Sydney and Los Angeles - were complete.
"We are hopeful that within days the A380 fleet will start flying again," he said.
As the hunt for clues went on, the bureau said that one piece of the shattered engine that had been found on Batam was being sent to Britain for examination by Rolls-Royce engineers, under the supervision of bureau investigators. Extra experts were being sent from Australia to Singapore to examine other debris.
Rolls-Royce Group PLC, a London-based aerospace, power systems and defense company separate from the car manufacturer, has said the investigation is in its early stages and that it is too early to draw any conclusions.
John Goglia, a former National Transportation Safety Board member and an expert on aircraft maintenance, said the photo showing the broken turbine disc indicates it was the disc that may have failed. The photo didn't show any signs of discoloration on the disc that would indicate overheating.
There are several reasons why a disc might fail, but they usually involve the metal used to make the disc or the manufacturing method, Goglia said. He cautioned that he was looking at one photo, which was not enough information to make a definitive judgment.
Meanwhile on Sunday, passengers on a Qantas Boeing 747-400 that had engine trouble a day after the A380 began arriving in Australia on alternative flights. The 747-400's engine overheated six minutes after takeoff from Singapore and had to make an emergency landing.
"I could see from my seat the fire," said Amon Franz, a tourist from Austria who was one of several passengers who described seeing one of the plane's engines flame out. "Most people were crying around me ... and those seconds was a really hard experience for me."
Joyce, the Qantas executive, said the 747-400 incident was unrelated to the A380 event and was not as worrying.
The crew and captain of the stricken A380 were among those aboard the 747-400 that had the engine trouble Friday, the Sun Herald newspaper reported.