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Missing Malaysian Jet’s Crew Was Probably Unresponsive, Officials Say Pressure Loss Is Explored In Vanishing Of Jetliner
(about 11 hours later)
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. CANBERRA, Australia — Nearly four months after Malaysia Airlines Flight 370 vanished into the night, Australian transportation officials said in a report on Thursday that the plane kept flying until it ran out of fuel, most likely because the cockpit crew had become unresponsive because of oxygen deprivation.
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 Boeing 777-200 headed south across the Indian Ocean on March 8 was that the crew was suffering from hypoxia or was unresponsive for another reason. The plane appears to have flown in a straight line south across the Indian Ocean, controlled entirely by the autopilot, Australian officials said. But they avoided offering hypotheses for why the plane had reached the northern end of the Indonesian island of Sumatra and had turned south in the first place, when it was supposed to travel the night of March 8 from Kuala Lumpur, the Malaysian capital, to Beijing.
Hypoxia occurs when a plane loses air pressure and the pilots, lacking adequate oxygen, become confused and incapable of performing even basic manual tasks. Malaysian radar records show that the Boeing 777-200 did a U-turn over the Gulf of Thailand instead, then banked right across the Malaysian Peninsula and then banked right again to reach the northern tip of Sumatra.
Pilots are trained to put on oxygen masks immediately if an aircraft suffers depressurization; 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. Evidence of an unresponsive crew as the plane flew south for more than five hours includes the loss of radio communications, a long period with no maneuvering of the aircraft, a steady cruise altitude and eventual fuel exhaustion and descent, the report said. It added that this could have been caused by hypoxia, or oxygen deprivation, among the cockpit crew.
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 across the Strait of Malacca before turning south. It is believed to have crashed somewhere in the southern Indian Ocean off the western coast of Australia, which has been coordinating the search. “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.
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. Hypoxia occurs when a plane loses air pressure and the pilots, lacking adequate oxygen, become confused and incapable of performing even basic manual tasks, though they continue to feel confident in their own abilities.
“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. 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 conclusively identifying a cause for the loss of the plane. Pilots are trained to put on oxygen masks immediately if an aircraft suffers depressurization; their masks have only an hour’s air supply, however. The plane, with 239 people aboard, made its turn south toward the Indian Ocean about an hour after it stopped responding to air traffic controllers. It is believed to have crashed somewhere in the southern Indian Ocean off the western coast of Australia. Australian officials have been coordinating the search.
There is no consensus among investigators, even within the Australian government, on the hypoxia or unresponsive-crew theory. Other officials, who insisted on anonymity because of the diplomatic sensitivity of the issue with Malaysia and China — most of the flight’s passengers were Chinese — 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 also killed everyone else on the plane. Passengers’ masks have only a few minutes of oxygen, based on the theory that the pilot of a troubled plane will quickly descend to an altitude at which there is little need for a supplemental air supply.
The report added that the theory of an unresponsive crew possibly suffering from hypoxia was an operating assumption for the search and was not meant to infringe on Malaysia’s authority as the government responsible for conclusively 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. Angus Houston, the retired head of the Australian military who is overseeing the country’s search, said in a telephone interview this month that he assumed that the flight had been on autopilot even if a conscious pilot had been at the controls. That is because a Boeing 777 is a very difficult plane to fly manually.
Other officials, who insisted on anonymity because of the diplomatic sensitivity of the issue with Malaysia and China — most of the flight’s passengers were Chinese — 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 also killed everyone else aboard.
Advocates of the hypoxia theory argue that pilot suicide cases tend to involve pilots who crashed their planes suddenly, not after hours of flight. A clinical psychologist advising the investigation has been very skeptical of the suicide theory, saying it would be highly unusual for a suicidal person to proceed with such a deadly plan over many hours, investigators said.Advocates of the hypoxia theory argue that pilot suicide cases tend to involve pilots who crashed their planes suddenly, not after hours of flight. A clinical psychologist advising the investigation has been very skeptical of the suicide theory, saying it would be highly unusual for a suicidal person to proceed with such a deadly plan over many hours, investigators said.
Depressurization of an aircraft can occur from mechanical failure, an attempted hijacking or many other causes. The Australian report did not speculate on why the crew might have succumbed to hypoxia or otherwise become unresponsive. Depressurization of an aircraft can occur from mechanical failure, an attempted hijacking or many other causes. If a plane undergoes gradual depressurization, pilots do not necessarily notice that they are losing oxygen, and with it, their mental clarity. Masks are supposed to deploy automatically with a loss of air pressure, but they need to be fitted properly for a full flow of oxygen.
At a news conference here 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 as to who might have done so and why. “If the autopilot is operational, it’s because it has been switched on,” Mr. Dolan said. At a news conference here on Thursday afternoon, 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 as to who might have done so and why. “If the autopilot is operational, it’s because it has been switched on,” Mr. Dolan said.
Based on recent analysis of data from electronic “handshakes” between the plane and a satellite operated by the company Inmarsat, the Boeing 777-200 appears to have followed a straight track to the south after making a left turn somewhere west of the northern tip of the Indonesian island of Sumatra, Mr. Dolan added. Based on recent analysis of data from electronic “handshakes” between the plane and a satellite operated by the company Inmarsat, the Boeing 777-200 appears to have followed a straight track to the south, Mr. Dolan added.
Warren Truss, the deputy prime minister of Australia and also the minister for infrastructure and regional development, said at the news conference with Mr. Dolan that Australia planned to hire a contractor to scour a rectangular area of ocean floor covering 23,000 square miles. Up to three deep-sea submersibles will be used for the yearlong endeavor, starting in August. Warren Truss, the deputy prime minister of Australia and also the minister for infrastructure and regional development, said at the news conference that Australia planned to hire a contractor to scour a rectangular area of ocean floor covering 23,000 square miles. Up to three deep-sea submersibles will be used for the yearlong endeavor, starting in August.
By comparison, a fruitless search of ocean floor farther to the northeast by a United States Navy contractor in late April and May, following the detection of acoustic pings initially believed to have been from the aircraft’s so-called black boxes, covered only 332 square miles. By comparison, a fruitless search of ocean floor 500 miles farther to the northeast by a United States Navy contractor in late April and May, after the detection of acoustic pings initially believed to have been from the aircraft’s so-called black boxes, covered only 332 square miles.
That area was chosen based on the supposition that the plane, limping along at reduced speed, had burned a great deal of fuel in extreme altitude changes or had been zigzagging somewhere along its course. But the new conclusion, that the aircraft traveled on a straight course under full control of the autopilot, does little to erase the mystery of why the plane ever departed from what was supposed to have been a routine red-eye flight. The midpoint of the new search area is 1,100 miles west-northwest of Perth, Australia. The Fugro Equator, the vessel under contract by Australia, is already mapping at the near end of the new search area to Australia, about 960 miles northwest of Perth.
Angus Houston, the retired head of the Australian military who is overseeing the country’s search, said in an interview earlier this month that he assumed that the flight had been on autopilot even if a conscious pilot were at the controls. That is because a Boeing 777 is a very difficult plane to fly manually. The new search area runs 400 miles along the “seventh arc” of possible locations for the aircraft, based on the seventh and last electronic handshake that it had with the satellite. The area has a width of only 58 miles on the assumption that the plane was on autopilot and quickly stalled and crashed when it ran out of fuel.
Two deep-sea survey vessels, one contracted by Australia and the other sent by China, have already begun mapping the ocean floor in the new search area, looking for undersea mountains and hills that could wreck a submersible if it is towed into one. Mr. Dolan said that the three-month mapping project was not designed to detect aircraft debris, and that there was a less than 5 percent chance that it would do so.
The midpoint of the new search area is 1,100 miles west-northwest of Perth, Australia. The Fugro Equator, the vessel under contract by Australia, is already mapping at the near end of the new search area, about 1,000 miles northwest of Perth.
The new search area runs 400 miles along the so-called seventh arc of possible locations for the aircraft, based on the seventh and last electronic handshake that it had with the satellite. The area has a width of only 58 miles, on the assumption that the plane was on autopilot and quickly stalled and crashed when it ran out of fuel.
If a conscious pilot were at the controls, the aircraft might have glided up to 100 miles further. At the news conference Thursday, held in the Blue Room of Australia’s Parliament House, Mr. Truss and Mr. Dolan said a much wider area of the ocean floor had a low-probability chance of being the final resting place of Flight 370 but there were no immediate plans to search that wider area.
Aircraft and ships searched the new search area for floating debris on the 21st through 26th days after the plane disappeared, and found nothing.Aircraft and ships searched the new search area for floating debris on the 21st through 26th days after the plane disappeared, and found nothing.
Tim Farrar, a satellite communications consultant in Menlo Park, Calif., one of a group of satellite experts who have been independently analyzing clues to Flight 370’s disappearance, said in a telephone interview that assuming that the plane was on autopilot simplified the search and reduced the range of places along the seventh arc where the plane might have come to rest. But he cautioned that a conscious pilot still might have been at the controls while leaving the flight on autopilot. Tim Farrar, a satellite communications consultant in Menlo Park, Calif., one of a group of satellite experts who have been independently analyzing clues to Flight 370’s disappearance, said in a telephone interview that assuming that the plane was on autopilot simplified the search and reduced the range of places along the seventh arc where the plane might have come to rest.
The report showed many computer simulations, a few of them including flights far to the east or west of the new search zone. Mr. Dolan declined to say what percentage of the computer simulation results showed the aircraft ending up within the new search area. But he cautioned that the electronic handshakes could also be compatible with stable flight controlled by a human pilot. He questioned whether the report or Australian officials had enough information to justify their assumption that the plane was being controlled entirely by autopilot.
Mr. Farrar cautioned that the new search might not find the plane either. “It wouldn’t surprise me if there’s a reasonable probability it’s outside the defined search area,” he said. “It’s going to be a difficult search.” Mr. Farrar said that the new search might not find the plane either. “It wouldn’t surprise me if there’s a reasonable probability it’s outside the defined search area,” he said. “It’s going to be a difficult search.”