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CANBERRA - Qantas yesterday defended its maintenance standards and safety record as Australian and American investigators continued to search for the cause of an explosion that ripped a huge hole in the fuselage of a Boeing 747-400 jumbo as it flew from Hong Kong to Melbourne last Friday.
Speculation has narrowed to a missing oxygen cylinder stored under the passenger compartment, suggesting it may have disintegrated and punched out a 2m by 4m section of the aircraft's skin.
If confirmed, this would be the first time an oxygen cylinder has exploded aboard a passenger aircraft.
Investigators said yesterday that fragments which could be from the missing oxygen cylinder had been found in the jumbo's passenger cabin.
Neville Blyth, of the Australian Transport and Safety Bureau said in Manila that a valve and other fragments would be tested to see if they came from the tank, designed to provide passengers' emergency oxygen.
He said the fragments were found close to where the cylinder had been stored.
No one was hurt in Friday's emergency on the Boeing 747-400. Flight QF30, flying at 8840m with 365 people aboard, immediately plunged 6000m as pilot John Bartels, 53, fought to bring it under control.
Passengers complained that some oxygen masks had not automatically released, and that a number had been faulty.
Bartels told the Sunday Herald Sun he and the two other members of the flight crew had worked together and focused on setting the aircraft down in an emergency landing at the Philippines capital of Manila.
Qantas, suffering heavily from the impact of soaring oil prices and global financial market turmoil, has now taken a major hit to its reputation as newspapers and TV bulletins around the world carried pictures of the stricken jumbo.
The airline has already come under attack from the engineers' union for shifting maintenance work overseas and announcing 1500 redundancies worldwide. And yesterday it drew further fire after problems with a new baggage check-in system caused chaos at Sydney airport.
News reports also claimed that corrosion had earlier been found in the damaged Being, and that the US Federal Aviation Administration had ordered safety checks on oxygen cylinders on all American-registered Boeing 747-400 series aircraft.
The FAA issued the instruction after reports that many cylinders had not been properly heat-treated and needed to be replaced, the Sydney Morning Herald reported.
The incident also coincided with the announcement of chief executive Geoff Dixon's retirement, and his replacement in November by Irish-born Alan Joyce, at present chief executive of cut-price Qantas offshoot Jetstar.
Announcing the move yesterday, chairman Leigh Clifford said Dixon's retirement had long been planned and was not connected to the emergency on QF30., which had been handled well by its crew.
"We are proud of how it was handled, in what could have been a terrible incident," he said.
Australian Transport Safety Bureau experts have been joined in Manila by others from Boeing and the American FAA to determine not only the cause of the emergency, but also if there is a risk of a repeat in other jumbos.
Civil Aviation Safety Authority spokesman Peter Gibson told ABC radio that investigators would focus on the likelihood of an oxygen tank - one among dozens carried by jumbos - exploding and punching the hole in QF30's fuselage.
"As far as we can determine this has never happened before on a passenger aircraft," he said.
"There are no reports of it anywhere, so its very, very unusual, and obviously understanding why that happened will be absolutely critical to making sure it can't occur again."
Gibson said possible causes of a cylinder exploding could include metal fatigue, a failure of its regulator valve, overheating, or being struck and punctured by another object. The investigations are expected to take several days, and the final report two to three months.
Qantas has not yet had full access to the aircraft and has denied reports describing the jumbo as a "rust bucket" - that major corrosion had been found during a maintenance check and later refurbishment of the 17-year-old Boeing.
Dixon and the CAA have said corrosion did not play a part in the emergency.
Dixon defended the airline's safety and maintenance standards, which unions have claimed are slipping because of cost pressures and the shifting of work overseas.
"We'll look to see if there's anything wrong, but we believe that everything in that aircraft was in good shape when it took off," he said.
