Analysis of the Malaysia data suggests the plane, with 239 people on board, diverted from its intended northeast route from Kuala Lumpur to Beijing and flew west instead, using airline flight corridors normally employed for routes to the Middle East and Europe, said sources familiar with investigations into the Boeing 777's disappearance.

Two sources said an unidentified aircraft that investigators believe was Flight MH370 was following a route between navigational waypoints when it was last plotted on military radar off the country's northwest coast.

This indicates that it was either being flown by the pilots or someone with knowledge of those waypoints, the sources said.