Oxygen cylinder link to jet blast

The Boeing 747-400 was cruising at 29,000 feet on Friday with 346 passengers aboard when it was shaken by what passengers described as an explosion. Oxygen masks dropped from the ceiling as the plane descended rapidly and debris flew through the cabin from a hole that suddenly appeared in the floor.

The plane, en route to Melbourne, Australia, managed to land safely minutes later at the Manila airport. There were no injuries.

Four specialists from the Australian Transport Safety Bureau inspected the aircraft on Saturday and are continuing through the weekend. Boeing and the US National Transportation Safety Board are also sending specialists to assist.

The possibility of an explosion was one of several scenarios being considered by investigators, said Julian Walsh of the Australian Transport Safety Bureau.

"There are oxygen cylinders contained in the cargo compartment, but the relevance of that will certainly be covered in the investigation," he told reporters.

An official with the US Transportation Security Administration said initial reports indicated no link to terrorism.

Meanwhile, some passengers told Australian media that their oxygen masks failed to work properly during the crisis, leading some to nearly pass out.

Other passengers, while applauding the pilot and crew's performance, told of having to share oxygen masks between three people because of faulty or broken emergency equipment.

Boeing spokeswoman Liz Verdier said the design of the Qantas jet included dozens of oxygen tanks located throughout the lower part of the aircraft, including below the passenger compartment where the hole was.