U.S. intelligence agencies put together an assessment in the wake of the disappearance of Malaysia Airlines Flight 370 indicating that the plane was deliberately taken off course, according to a source with knowledge of the matter. The assessment β made months ago and concerning what most likely happened to the plane β which disappeared in March 2014, also said that the Boeing 777 was also potentially deliberately downed, the source said. http://abcnews.go.com/International/mh370-us-intel-assessment-suggested-plane-deliberately-off/story?id=32796296
Watched that, i think they came to that conclusion based on the fact that they found a flight simulator in his house and that he had formatted the harddrives before he flew MH370. For sure its a mystery how a plane can just disappear without any physical debris, even pieces of luggage or anything that could have identified the plane.
The Indian ocean is huge and i understand there are trenches as deep as Mt Everest. Ohh there is the possible plane computer systems hacking theory.
Then that means the plane is sitting somewhere at the bottom of the ocean and from media reports (investigator theories NOT MINE!) it might have plunged into the ocean nose first and maybe a large portion of it might be still intact, hence the lack of debris.