Oxygen bottle blamed for Qantas plane explosion

The Qantas 747-400 suffered a sudden loss of cabin pressureduring a flight from Hong Kong to Melbourne on July 25, forcingthe aircraft to make an emergency descent before diverting tothe Philippines, where it landed safely in Manila.

Australian Transport Safety Bureau (ATSB) director JulianWalsh said it was clear one of the plane's cargo hold oxygenbottles had ruptured, blowing a hole in the fuselage andsending the bottle up through the passenger cabin floor.

"It happened very quickly," Walsh told reporters as hereleased a preliminary report on the ATSB's investigations.

"The oxygen bottle went from the base of the aircraft, tothe ceiling of the first-floor cabin," he said, adding it hitthe handle of the cabin door on the way.

But the preliminary report into the incident gave noexplanation on why the oxygen cylinder, the fourth in a line ofseven cylinders along the right side of the cargo hold, failedunder pressure.

The tank was part of a batch of 94 cylinders made inFebruary 1996, and had undergone regular three-yearly checks.It was serviced and refitted to the plane six weeks before itfailed.

The resulting explosion tore a 2-metre by 1.5 metre hole inthe plane's fuselage, destroying cabling and disabling theplane's instrument landing system, one of the flight managementcomputers, and the anti-skid brake system, the report said.

The pilot landed the plane manually, with help from airtraffic controllers in Manila, where all 346 passengers and 19crew disembarked safely. (Reporting by James Grubel; Editing byValerie Lee)