Missing Airplane Flew On for Hours

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.
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.

As part of its maintenance agreements, Malaysia Airlines transmits its engine data live to Rolls-Royce for analysis. The system compiles data from inside the 777's two Trent 800 engines and transmits snapshots of performance, as well as the altitude and speed of the jet.
Those snippets are compiled and transmitted in 30-minute increments, said one person familiar with the system. According to Rolls-Royce's website, the data is processed automatically "so that subtle changes in condition from one flight to another can be detected."
The engine data is being analyzed to help determine the flight path of the plane after the transponders stopped working. The jet was originally headed for China, and its last verified position was half way across the Gulf of Thailand.
A total flight time of five hours after departing Kuala Lumpur means the Boeing 777 could have continued for an additional distance of about 2,200 nautical miles, reaching points as far as the Indian Ocean, the border of Pakistan or even the Arabian Sea, based on the jet's cruising speed.
Read news in full 13/03/14 Wall Street Journal