The flight was interrupted on the Hong Kong leg by an exploding oxygen tank that ruptured the fuselage just forward of the starboard wing root.

[5] 53-year-old Captain John Bartels (who had flown for Qantas for 25 years and the Royal Australian Navy for 7 years) and his co-pilots, Bernd Werninghaus and Paul Tabac, made an emergency descent to a breathable altitude of about 10,000 feet (3,048 m) and diverted to Ninoy Aquino International Airport, Metro Manila, Philippines.

The Australian Transport Safety Bureau interviewed passengers who reported problems with the oxygen masks as part of their investigation.

They stated that these initial investigations had found that the aircraft took about five and a half minutes to descend from the decompression event at 29,000 feet to the altitude of 10,000 feet and that it appeared that part of an oxygen cylinder and its valve had entered the passenger cabin, then impacted with the number 2 right door handle, turning it part way.

[12] The FAA had recently issued airworthiness directives regarding problems with the masks on this and several other Boeing commercial aircraft models.

[29] The ATSB issued two Safety Advisory Notices, advising responsible organisations to review procedures, equipment, techniques and personnel qualifications for maintenance, inspection and handling of aviation oxygen cylinders.

""Following an emergency descent to 10,000 ft, the flight crew diverted the aircraft to Ninoy Aquino International Airport, Manila, Philippines, where it landed safely.

""A team of investigators, led by the Australian Transport Safety Bureau (ATSB) and including representatives from the US National Transportation Safety Board (NTSB), the US Federal Aviation Authority (FAA), Boeing and the Civil Aviation Authority of the Philippines (CAAP) examined the aircraft on the ground in Manila.

From that work, it was evident that the oxygen cylinder (number-4 in a bank along the right side of the forward cargo hold) had burst in such a way as to rupture the adjacent fuselage wall and be propelled upwards; puncturing the cabin floor and impacting the frame and handle of the R2 door and the overhead cabin panelling.

It was evident that the cylinder had failed by bursting through, or around the base – allowing the release of pressurised contents to project it vertically upwards.

While it was hypothesised that the cylinder may have contained a defect or flaw, or been damaged in a way that promoted failure, there was no evidence found to support such a finding.

Nor was there any evidence found to suggest the cylinders from the subject production batch, or the type in general, were in any way predisposed to premature failure.