article-2579524-1C3A5A5B00000578-353_634x432US investigators think that Malaysian Airlines flight 370 remained airborne for four more hours after vanishing from its last recorded position – raising the startling prospect the plane could have been hijacked. Officials suspect that the plane flew for a total of five hours based on data automatically downloaded from the Boeing 777’s Rolls Royce engines and sent back to the ground as part of a routine monitoring program. US counter-terrorism teams are now pursuing the astonishing possibility that the plane and its 239 passengers were diverted to an undisclosed location ‘with the intention of using it later for another purpose’. MORE