Post-explosion, Qantas checks oxygen tanks in its entire fleet of Boeing 747-400 aircraft

Qantas Airways has completed examination of all oxygen tanks aboard its fleet of Boeing 747-400s aircraft (jumbo aircraft). This has been done in an attempt to find out the cause of the on-board explosion in the Qantas Airways’ jumbo jet on a flight from London to Melbourne in Australia on July 25, 2008. The Qantas Flight 30, on a flight from London to Melbourne in Australia, was forced to make an emergency descent and divert to Manila, the capital of the Philippines, after the explosion bore a hole in the cargo hold near the wing-root underneath the R2 door.

Media reports said that Qantas Airways Limited, the national airline of Australia, is yet to offer any comment on the results of the inspection.

The air safety investigators who conducted the probe homed in on an oxygen bottle as the cause of the on-board explosion in the Boeing 747-400 aircraft during flight. The fragments of the oxygen cylinder that exploded had made a hole the size of a car in the fuselage and caused rapid decompression in the cabin.

Meanwhile, the Australian Transport Safety Bureau – the Australian federal government body responsible for investigating transport-related accidents and incidents within Australia – is bringing the fragments, which include part of the valve, back to Australia. This is being done for experts to examine the fragments in the context of other evidence from the aircraft, such as marks and other damage.

However, the investigators are still unsure about the nature of the failure of the green oxygen bottle, which is about the size of a scuba tank. The exploded oxygen bottle was the fourth in a bank of 13 intended to supply oxygen to crew and passengers.

According to aviation experts, a failure involving explosion of an oxygen bottle is unprecedented in a Boeing aircraft.

A statement form Qantas Airways said the oxygen bottles aboard its aircraft are regularly inspected and also subjected to a detailed check once very 36 months. However, following the incident, the airline is conducting a check of all oxygen bottles on its other 747-400 aircraft.

Julian Walsh, director of aviation safety investigations of the Australian Transport Safety Bureau, was quoted by the newspaper The Australian as indicating that the detailed investigation would take time and that “there might not be any quick answers.”

“Understanding the mode of failure of the tank,” Walsh added, “is going to be key in terms on whether it was related to the valve or the physical tank itself. All of that is going to take a fair of bit of analysis and examination and I don’t know that there’s going to be a short answer as to how that happened.”

The crew of the affected Qantas Flight 30, who handled the situation admirably and thus saved the passengers and thee aircraft, has been praised as heroes by the media, by the Qantas officials as well as by the investigators.

Investigators have confirmed that that the three instrument-landing systems and the anti-skid system of the Boeing 747-400s aircraft in question were not available for the aircraft’s arrival in Manila. This meant that the pilots made a visual approach. However, the other navigation instruments as well as engines and hydraulics were functioning normally, the investigators said.

Following complaints from passengers about problems with oxygen masks, the investigating team examined the passenger cabin and found that most of the oxygen masks had been deployed correctly.

The investigators also found that 484 masks had been deployed for the 346 passengers and 19 crew and 418 had been activated. In a small number of cases, the elastic retaining strap appeared to have been adjusted, and a few masks did not deploy.

The Australian Transport Safety Bureau is investigating whether the oxygen system was adequate for the five-and-a-half-minute descent of the aircraft to 10,000ft, where masks were no longer required.

According to an official of the Australian Transport Safety Bureau, the information downloaded from the affected jumbo jet’s flight data recorder so far indicates that the plane took about five-and-a-half minutes to make its emergency descent from 29,000ft to 10,000ft at an average descent rate of 4,000 feet per minute.