Investigations suggest that expert would have disabled jets systems
The investigation into the disappearance of Malaysia Airlines Flight 370 sharpened its focus on sabotage, amid strong indications that one or more people on the plane deliberately changed its course and tried to mask its location.
Officials suspect two different systems were shut off after the plane took off last weekend.
About an hour into the flight, the plane's transponders stopped functioning, making it much more difficult for air-traffic control personnel to track or identify it via radar.
Such a turn wouldn't have been part of the original authorized route programmed in the flight-management computer that controls the autopilot.