U.S. investigators suspect that Malaysia Airlines Flight 370 stayed in the air for about four hours past the time it reached its last confirmed location, according to two people familiar with the details, raising the possibility that the plane could have flown on for hundreds of additional miles under conditions that remain murky.
Aviation investigators and national security officials believe the plane flew for a total of five hours, based on data automatically downloaded and sent to the ground from the Boeing Co. 777's engines as part of a routine maintenance and monitoring program.
That raises a host of new questions and possibilities about what happened aboard the widebody jet carrying 239 people, which vanished from civilian air-traffic control radar over the weekend, about one hour into a flight to Beijing from Kuala Lumpur.
Six days after the mysterious disappearance prompted a massive international air and water search that so far hasn't produced any results, the investigation appears to be broadening in scope.
U.S. counterterrorism officials are pursuing the possibility that a pilot or someone else on board the plane may have diverted it toward an undisclosed location after intentionally turning off the jetliner's transponders to avoid radar detection, according to one person tracking the probe.
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The investigation remains fluid, and it isn't clear whether investigators have evidence indicating possible terrorism or sabotage. So far, U.S. national security officials have said that nothing specifically points toward terrorism, though they haven't ruled it out.
But the huge uncertainty about where the plane was headed, and why it apparently continued flying so long without working transponders, has raised theories among investigators that the aircraft may have been commandeered for a reason that appears unclear to U.S. authorities. Some of those theories have been laid out to national security officials and senior personnel from various U.S. agencies, according to one person familiar with the matter.
WSJ has confirmed that the pilot had the ability to manually turn off the transponder on Flight MH370. A mid-air catastrophe could have destroyed it. Why is the transponder so significant? WSJ's Jason Bellini has #TheShortAnswer.
At one briefing, according to this person, officials were told investigators are actively pursuing the notion that the plane was diverted "with the intention of using it later for another purpose."
As of Wednesday it remained unclear whether the plane reached an alternate destination or if it ultimately crashed, potentially hundreds of miles from where an international search effort has been focused.
In those scenarios, neither mechanical problems, pilot mistakes nor some other type of catastrophic incident caused the 250-ton plane to mysteriously vanish from radar.
The latest revelations come as local media reported that Malaysian police visited the home of at least one of the two pilots.
