Flight MH370 investigators consider oxygen starvation as cause of disappearance
Plane on 'autopilot before crash', with course pointing to likely depressurisation and hypoxia rendering crew unconscious
Investigators searching for flight MH370 consider a catastrophic event leading to oxygen starvation the most likely scenario in the disappearance of the Malaysian Airlines Boeing 777.
The Australian-led search team say that the plane was flying on autopilot on a consistent course when it finally crashed into the ocean when its engines flamed out.
The search team stressed that this was only a working assumption – rather than any cause identified by accident investigators under the legal lead of the Malaysian government. But a report from the Australian Transport Safety Bureau (ATSB) said that of the classes of accidents that appeared relevant, satellite data of the flight pattern pointed to likely depressurisation and hypoxia rendering the crew unconscious.
It says the loss of MH370 most resembles flights including the Helios Airways "ghost flight" of 2005, which flew for two hours on autopilot after air pressure dropped and its pilots lost consciousness before crashing into a mountain 25 miles north of Athens.
Chief commissioner of ATSB, Martin Dolan, said it was "highly, highly likely" that MH370 was on autopilot for hours before it crashed, because of the orderly path the plane took.
The assumptions have been made as investigators redefine the search area for the plane further south in the Indian Ocean. Searchers will spend three months mapping previously uncharted waters before a detailed underwater search can take place.
The Australian deputy prime minister, Warren Truss, announced the search for flight MH370 off Western Australia had moved further south and was still about 1,100 miles (1,800km) offshore.
An expert satellite working group defined a new search zone of up to 23,200 sq miles (60,000 sq km) along the arc in the southern Indian Ocean in the hunt for the plane which has so far been fruitless.
Mapping the new search area, through Chinese and Australian ships, is expected to take three months. The next stage has been given a provisional 12 month duration, although investigators have admitted it could last far longer.
Authorities are still confident the Malaysian Airlines plane is off Australia's west coast. Truss added: "Specialists have analysed satellite communications information, information which was never initially intended to have the capability to track an aircraft, and performed extremely complex calculations.
"The new priority area is still focused on the seventh arc, where the aircraft last communicated with satellite. We are now shifting our attention to an area further south along the arc based on these calculations."