Report says the crew was probably unresponsive.
March 30, 2014: Australian Defense ship Ocean Shield is docked at naval base HMAS Stirling while being fitted with an autonomous underwater vehicle and towed pinger locator to aid in the search for missing Malaysia Airlines Flight MH370, in Perth, Australia.
CANBERRA, Australia – The missing Malaysia Airlines jet appears to have been on autopilot as it flew south across the Indian Ocean until running out of fuel, and the likeliest scenario is that the crew of Flight 370 was unresponsive, possibly suffering from the effects of oxygen deprivation, Australian officials said Thursday in announcing a new deep-sea search for the aircraft.
A report issued by the Australian Transport Safety Bureau, outlining how the new search zone had been chosen, said the most likely scenario as the jet headed south across the Indian Ocean on March 8 was that the crew was suffering from hypoxia or was unresponsive for another reason.
Hypoxia occurs when a plane loses air pressure and the pilots, lacking adequate oxygen, become confused and incapable of performing even basic manual tasks.
Little oxygen supply
Pilots are trained to put on oxygen masks immediately if an aircraft depressurizes; their masks have an hour’s air supply, compared with only a few minutes for the passengers. The plane, which left Kuala Lumpur, Malaysia, bound for Beijing with 239 people aboard, made its turn south toward the Indian Ocean about an hour after it stopped responding to air traffic controllers.
The crew stopped communicating while the aircraft was over the Gulf of Thailand. The plane then did a U-turn, crossed the Malaysian Peninsula and then headed northwest before turning south. It is believed to have crashed somewhere off the western coast of Australia.
Evidence for an unresponsive crew as the plane flew south includes the loss of radio communications, a long period with no maneuvering of the aircraft, a steadily maintained cruise altitude and eventual fuel exhaustion and descent, the report said.
“Given these observations, the final stages of the unresponsive crew/hypoxia event type appeared to best fit the available evidence for the final period of MH370’s flight when it was heading in a generally southerly direction,” the document said.
No consensus on cause
The report added that this was an operating assumption for the search and that it was not meant to infringe on Malaysia’s authority as the government responsible for identifying a cause for the loss of the plane.
There is no consensus among investigators, even within the Australian government, on the hypoxia or unresponsive-crew theory. Other officials said some investigators still leaned toward the possibility that one of the pilots deliberately flew the plane to the southern Indian Ocean in a suicide mission that killed everyone on the plane.
At a news conference Thursday, Martin Dolan, the chief commissioner of the Australian Transport Safety Bureau, said someone on the plane had put it on autopilot, but he declined to speculate about who or why.