Men Who Killed Qantas - Matthew Benns [83]
However, ‘aviation sources’ were already informing newspapers that the routine corrosion checks mentioned by Dixon had in fact revealed that the 17-year-old Boeing jet was a ‘rust bucket’. 21 The Melbourne Age reported a plane spotters’ website claim that the jet, VH-OJK, named The City of Newcastle, had been sent in for ‘serious corrosion issues’ in February.22 The jet was 17 years old at the time of the incident, old by international 747 standards, where the average age is 15. Qantas had also just given the old jet an internal refit to modernise the interior for passengers.
The ATSB probe into the incident naturally focused on the damaged oxygen bottle. Months before the explosion on QF30, US authorities had ordered that all US-registered Boeing 747-400 series aircraft undergo a thorough check of the oxygen cylinders. It came after a report showed that many oxygen cylinders had not been properly heat treated. They needed to be replaced. The US Federal Aviation Administration directive said: ‘We are issuing this to prevent failure of the oxygen cylinder support under the most critical flight load conditions, which could cause the oxygen cylinder to come loose and leak oxygen. Leakage of oxygen could result in oxygen being unavailable for the flight crew or could result in a fire hazard in the vicinity of the leakage.’23 Australian authorities had already told Qantas to check its 747-400 oxygen bottles. The ATSB preliminary report said that the number four oxygen cylinder had ‘sustained a failure that allowed a sudden and complete release of the pressurised contents’.24 As the damaged cylinder was missing, other cylinders from the same 1996 batch as the QF30 one were located and subjected to a series of destructive and non-destructive tests. One was found to have ‘multiple linear indications … radiating outward from the cylinder neck’.25 The largest of these crack-like features was 12 mm long.
Just three days before the oxygen bottle exploded, the crew of VH-OJK noted in the technical log on a flight from Los Angeles to Sydney that the passenger oxygen needed to be refilled. But when maintenance staff on the ground checked the oxygen, they found that the servicing display panel and the cylinders themselves were within serviceable limits. The separate crew oxygen system had also had problems in the month before the explosion. The oxygen indicators on the flight deck recorded fluctuations in the crew oxygen levels. Each time the levels had to be checked manually and were found to be okay. Special approval was obtained from the Civil Aviation Safety Authority to keep flying the plane with this defect in the crew oxygen levels.
The ATSB investigation into the incident was hampered because vital information on one of the plane’s two black box flight recorders was taped over. The information cockpit voice recorder (CVR) monitoring system records the total audio environment in the cockpit. It runs on a continuous two-hour loop. Unfortunately, it kept recording as the aircraft was towed to the gate at Manila airport and wiped out the crucial time when the oxygen bottle exploded. Instead, investigators had to rely on the flight data recorder (FDR) black box system, which runs on a 25-hour continuous loop, and the non-crash protected quick access recorder (QAR) system, which is used by Qantas engineers to monitor maintenance issues. It was in sleep mode when