Missing Boeing 777 mystery: Communications systems were deliberately shut off

Sources said the Boeing 777 continued to attempt to transmit routine data about the plane's engines and performance to satellites.  

Malaysian authorities and Boeing apparently did not downlink the data, so details from plane's transmissions are not known.

But the fact that the jet was continuing to send signals is a strong indication that it did not crash immediately after radar contact was lost.  

The engines instead continued to run, Orr reported, meaning the plane continued in flight or perhaps was on the ground but still producing power.

In addition, U.S. radar experts have looked at the Malaysian military radar track, which seemed to show the jet flying hundreds of miles off course west of its flight path, and back across the Malay Peninsula.  

Sources said the radar appears to be legitimate and there is a strong reason to suspect that the unidentified blips - seen on military controller screens - are images of Flight 370.  

All of this, Orr said, leads to the possibility that the jet flew for hours toward the Indian Ocean. And it is the reason the search field has expanded in that direction.

That scenario would make finding the Boeing 777 a vastly more difficult task, and raises the possibility that searchers have spent days looking in the wrong place for the plane.