Accident investigators are eyeing the failure of an oxygen cylinder as the cause of an explosion that forced an emergency landing for a Qantas Boeing 747-400 flying from Hong Kong to Melbourne, Australia on July 24. Immediately after the explosion, the pilots took the widebody down to 10,000 feet, dumped approximately 50 tons of fuel and landed safely at Manila with no injuries to the 365 people on board. All three of the airplane’s independent instrument landing systems had failed.
Once the airplane landed, it was discovered that the blast had punched a seven-foot hole in the fuselage ahead of the right wing root, in the immediate location of the cylinder, parts of which were found in the cabin, where they came to rest after being propelled through the floor by the force of the explosion. One particularly large chunk apparently struck one of the cabin door handles, knocking it into the open position. Authorities say the door–designed so that it cannot be opened in flight–functioned as intended and there was never any danger of its opening another hole in the fuselage in flight.