KUALA LUMPUR, Malaysia — The mystery of Malaysia Airlines flight 370 deepened even further Saturday as authorities said someone on board the vanished jet made a series of highly technical actions to deliberately hide the plane from modern detection systems.
Malaysia's Prime Minister Najib Razak said that communications on the flight missing since last Saturday were disabled due to "deliberate action by someone on the plane" and that the last known signal from the airliner came more than seven hours after takeoff.
The revelation came amid an intensifying search involving dozens of planes and ships in an ever-widening area where the plane may have gone down. Military and government experts on Saturday pored over satellite and radar data that may shed light on the fate of the plane but so far there is no trace of debris.
Speaking at a news conference in Kuala Lumpur, Razak said investigators were making calculations to try to determine exactly how far the airliner traveled after its last point of contact.
According to new satellite data analyzed by the FAA, NTSB, AAIB and Malaysian authorities, the plane's communications from the Aircraft and Communications Addressing and Reporting System were cut off just before the aircraft reached the east coast of the peninsula of Malaysia, and the aircraft's transponder was turned off shortly thereafter, near the border of Malaysia and Vietnam, he said.
Flight 370 departed from Kuala Lumpur for Beijing at 12:40 a.m. on March 8 with 239 people on board. A multinational search effort involving 14 countries, 43 ships and 58 aircraft has turned up no trace of the Boeing 777, despite an expansive search that has widened with each passing day.
China, where the bulk of the passengers were from, expressed irritation over what it described as Malaysia's foot-dragging in releasing information about the search.
Investigators now have a high degree of certainty that one of the plane's communications systems - the Aircraft and Communications Addressing and Reporting System (ACARS) - was partially disabled before the aircraft reached the east coast of Malaysia, Najib said. Shortly afterward, someone on board switched off the aircraft's transponder, which communicates with civilian air traffic controllers.
Najib confirmed that Malaysian air force defense radar picked up traces of the plane turning back westward, crossing over Peninsular Malaysia into the northern stretches of the Strait of Malacca. Authorities previously had said this radar data could not be verified.
"These movements are consistent with deliberate action by someone on the plane," Najib said.
Although the aircraft was flying virtually blind to air traffic controllers at this point, onboard equipment continued to send "pings" to satellites.
U.S. aviation safety experts say the shutdown of communications systems makes it clear the missing Malaysia Airlines jet was taken over by someone who knew how the plane worked.
To turn off the transponder, someone in the cockpit would have to turn a knob with multiple selections to the "off" position while pressing down at the same time, said John Goglia, a former member of the U.S. National Transportation Safety Board. That's something a pilot would know, but it could also be learned by someone who researched the plane on the Internet, he said.
The Aircraft Communications Addressing and Reporting System (ACARS) has two aspects, Goglia said. The information part of the system was shut down, but not the transmission part. In most planes, the information section can be shut down by hitting cockpit switches in sequence in order to get to a computer screen where an option must be selected using a keypad, said Goglia, an expert on aircraft maintenance.
That's also something a pilot would know how to do, but that could also be discovered through research, he said.
But to turn off the other transmission portion of the ACARS, it would be necessary to go to an electronics bay beneath the cockpit. That's something a pilot wouldn't normally know how to do, Goglia said. The Malaysia plane's ACARS transmitter continued to send out blips that were recorded by satellite once an hour for four to five hours after the transponder was turned off. The blips don't contain any messages or data, but the satellite can tell in a very broad way what region the blips are coming from.
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event in April.
