Qantas Depressurisation

[Philip Argy]

Here's what the ATSB media release says:

The rupture of an oxygen cylinder on board a Qantas Boeing 747 was a unique event and highly unlikely to happen again according to the Australian Transport Safety Bureau (ATSB).
On 25 July 2008, an oxygen cylinder ruptured in the plane's forward cargo hold about an hour into a flight from Hong Kong to Melbourne. Part of the ruptured cylinder punctured the fuselage wall and damaged the cabin, causing the plane to rapidly depressurise. The plane then made an emergency descent and landed at the nearest suitable airport in Manila, Philippines. None of the 369 passengers and crew on board were injured.
ATSB Chief Commissioner, Mr Martin Dolan, said investigators conducted a comprehensive investigation to determine the cause of the rupture, despite missing the key piece of evidence.
'This was an unusual and challenging investigation as the key piece of evidence, the ruptured cylinder, was ejected from the plane and is at the bottom of the South China Sea,' Mr Dolan said.
'Since we didn't have the ruptured cylinder, we exhaustively tested and evaluated identical cylinders, including cylinders from the same manufacturing batch. Through these tests we did not identify any aspect of the cylinder design or manufacture that could pose a threat.
'As well, the published maintenance procedures were found to be valid and thorough, and inspection regimes appropriate. The investigation also found no record of any other related instances of aviation oxygen cylinder rupture.
'Given the widespread and long-term use of this type of cylinder, it was clear that this occurrence was a unique event.
'In light of the investigation's findings, it is our view that the risk of a similar rupture and consequent aircraft damage remains extremely remote."
The ATSB investigation report, released today, also provides safety advice for operators and organisations involved with aviation oxygen cylinders and operators of pressurised passenger transport aircraft. This advice included improving aircraft passenger briefings to ensure passengers are able to readily use emergency oxygen supply when required. This has already been addressed by Qantas.

The final report is well worth a read, not least because of the painstaking detail of the damage that was caused. The 14.9 MB final report is here: http://www.atsb.gov.au/media/2409291/ao2008053.pdf

I'm certainly looking forward to a similar level of detail when we get the ATSB's report on Nancy-Bird Walton's no.2 engine incident - their interim report on that is scheduled for 3 December.