N.Y. TIMES
The search for Flight 370 turned into a criminal investigation on Saturday, after Malaysia declared that the plane had been deliberately diverted and then flown for as long as seven hours toward an unknown point far from its scheduled route of Kuala Lumpur to Beijing.
Prime Minister Najib Razak of Malaysia said Saturday afternoon that he would seek the help of governments across a large expanse of Asia in the search for the Boeing 777, which has been missing for a week and had 239 people on board. The Malaysian authorities released a map showing that the last satellite signal received from the plane had been sent from a point somewhere along one of two arcs spanning large distances across Asia.
As part of the investigation, police officers were seen Saturday going to the home of the flight’s pilot, Zaharie Ahmad Shah, in a gated compound, and the Malaysian news media reported that a search had taken place.....
One arc runs from the southern border of Kazakhstan in Central Asia to northern Thailand, passing over some hot spots of global insurgency and highly militarized areas. The other arc runs from near Jakarta to the Indian Ocean, roughly 1,000 miles off the west coast of Australia.
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| An Indonesian rescue team assisted in the search for the missing plane in the Indian Ocean near Sumatra Island. Credit European Pressphoto Agency |
He said one communications system had been disabled as the plane flew over the northeast coast of Malaysia. A second system, a transponder aboard the craft, abruptly stopped broadcasting its location, altitude, speed and other information at 1:21 a.m., while the plane was a third of the way across the Gulf of Thailand from Malaysia to Vietnam.
Military radar data subsequently showed that the plane turned and flew west across northern Malaysia before arcing out over the wide northern end of the Strait of Malacca, headed at cruising altitude for the Indian Ocean.
The flight had been scheduled to land at 6:30 a.m. in Beijing, so when its last signal was received, at 8:11 a.m., Mr. Najib said, it could have been nearly out of fuel. “The investigation team is making further calculations, which will indicate how far the aircraft may have flown after the last point of contact,” Mr. Najib said, reading a statement in English. “Due to the type of satellite data, we are unable to confirm the precise location of the plane when it last made contact with a satellite.”
The northern arc Mr. Najib described passes near some of the world’s most volatile countries that are home to insurgent groups, but also over areas with a strong military presence and robust air defense networks, some run by the American military.
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| Japanese coast guard crews searched for the missing flight over the waters of the South China Sea on Saturday. Credit Edgar Su/Reuters |
American investigators have been provided with much of the flight data obtained from radar and satellites, but they say they have far less information about what the Malaysian government has uncovered about the pilots and passengers or the Malaysian inquiry. Soon after the plane disappeared, F.B.I. agents and other American investigators “scrubbed” the names of the pilots and passengers — including two Iranian men who traveled on stolen passports — to determine whether they had any connection to terrorists and found none, according to the officials.
Officials in Washington say they are frustrated because they believe that the F.B.I. could be of substantial assistance.
The Malaysian government has said that analyzing this data is a slow and painstaking process.
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| An Indonesian rescue crew searched in the Andaman Sea on Saturday. Credit Chaideer Mahyuddin/Agence France-Presse -- Getty Images |
David Learmount, operations and safety editor for Flightglobal, a news and data service for the aviation sector, said that the Malaysian government could have acted far sooner on the information pointing to someone’s seizing control of the plane.
Mikael Robertsson, a co-founder of Flightradar24, a global aviation tracking service, said the way the plane’s communications had been shut down pointed to the involvement of someone with considerable aviation expertise and knowledge of the air route, possibly a crew member, willing or unwilling.
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| Malaysian and Japanese crews searched for the missing Malaysian flight over the waters of the South China Sea on Saturday. Credit Edgar Su/Reuters |
The Boeing’s transponder was switched off just as the plane passed from Malaysian to Vietnamese air traffic control space, thus making it more likely that the plane’s absence from communications would not arouse attention, Mr. Robertsson said by telephone from Sweden.
Xu Ke, a former commercial pilot who has advised the Chinese government on aviation security, said the details suggested that at least one crew member, most likely one of the pilots, was involved in seizing control of the aircraft, either willingly or under coercion.
The possible northern corridor ...bristles with military radar, making it more likely that the plane either went south or, if it did fly north, did not make it far, Mr. Robertsson said.
“I don’t really think that the aircraft could have flown so far over the land, because it would need to pass over so many countries that someone should have picked it up,” he said. “If they had taken the northern corridor, they could have gone down before they reached land, so it’s also possible.”
Reconstructing the Plane’s Path
The main communications systems of the Malaysia Airlines plane were turned off about 40 minutes into the flight, forcing investigators to try to piece together the plane’s location from other systems.
Transponder
Secondary Radar and Text Updates
Air traffic controllers typically know a plane’s location based on what is called secondary radar, which requests information from the plane’s transponder. A plane also uses radio or satellite signals to send regular updates through ACARS, the Aircraft Communications Addressing and Reporting System. Both of those systems were turned off.
Primary Radar
Two Malaysian military radar stations tracked a plane using primary radar, which sends out radio signals and listens for echoes that bounce off objects in the sky. Primary radar does not require a plane to have a working transponder.
SATELLITE
Satellite Communications
If ACARS updates are turned off, the plane still sends a “keep-alive” signal, that can be received by satellites. The signal does not indicate location, but it can help to narrow down the plane’s position. A satellite picked up four or five signals from the airliner, about one per hour, after it left the range of military radar.
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... based on what is known about the flight’s trajectory, investigators are strongly favoring the southern corridor as the likely flight path