Data transmission system on MH370 deliberately disabled
Found on New Scientist on Saturday, 15 March 2014
It has taken time to identify the correct search areas, Razak says, because it is now clear to investigators that the radar transponders and the flight data transmission system in the missing Malaysian airliner were deliberately disabled by somebody on the aircraft trying to hide its position and heading.
In other words somebody who knew what they were doing - or who may have been forcing a pilot to do it - was trying to obscure the plane's position. But Rezak stops short of saying this means the plane was necessarily hijacked.
It's a little amazing when you think about it. On a plane, where everything is designed to be as reliable as possible and every important system has backup systems, the pilot can disable something as essential as the transmission of data. Even more amazing is that GPS bugs cost only a few dollars and a couple of them could be easily added so the plane will send its position data, no matter what the pilot does.