A British aviation expert says missing MH370 was taken out of the sky by a "highly qualified" person who had advanced flight skills.
Independent experts believe that the Malaysia Airlines plane was taken off course and deliberately crashed into the remote sea by its captain Zaharie Ahmad Shah.
One recent report claimed the captain was depressed and had locked his co-pilot out of the cockpit before taking the plane on a suicide mission that killed all 239 people on board.
David Learmount, a British pilot and aviation commentator, said only a person with a lot of training and an intimate knowledge of that type of plane could seize control of the aircraft.
Mr Learmount, consulting editor at FlightGlobal said: “It was a highly qualified human being, well-trained in the workings of the 777 who did this.”
The person behind the controls when the plane was turned around would have known about dead zones in air traffic control, he added.
The plane is believed to have crashed in the southern Indian Ocean after it was taken off course during a flight from Kuala Lumpur to Beijing in March 2014.
The plane flew for hours before it ended up in the sea.