Accident investigators have confirmed that a burst oxygen tank was the cause of the rupture on board the Qantas Boeing 747 that was forced to make an emergency landing last week.
Julian Walsh, director of aviation safety at the Australian Transport Safety Bureau, said: “The ATSB can confirm that it appears that part of an oxygen cylinder and valve entered the passenger cabin and impacted the number 2 right door frame handle, thereby moving the handle part way towards the open position.”
The tank is designed to provide oxygen to passengers during an emergency. But a number of passengers reported that some of the oxygen masks appeared not to function correctly when they deployed from the overhead modules.
Also recovered were a number of component parts including part of a valve in the vicinity of the breech. However, it is yet to be determined whether these components are part of the aircraft system.
Qantas has ordered all oxygen tanks on its fleet of 747-400s to be urgently inspected. It has also emerged that the US Federal Aviation Administration issued a directive, which became effective in May, warning airlines to inspect oxygen cylinders on 747-400s.
The directive was issued amid fears they may not have been properly heat treated, which could lead to oxygen leaks and fire hazards. However, David Cox, the Qantas head of engineering, said the FAA directive applied to a different type of oxygen system to the one being scrutinised in the investigation into Friday’s crash.
The plane was carrying 365 people when it was forced to make an emergency landing in Manila after part of the fuselage was ripped open at 30,000 feet, sucking pressure from the cabin.
The Boeing 747-400 had left Hong Kong an hour earlier en route from London to Melbourne when the piece broke off, leaving a gaping four-metre hole down the right side. Passengers reported hearing a loud bang followed by air and debris rushing through the cabin. The pilot made a rapid descent, landing safely in Manila airport.