Malaysia Airlines lost contact with one of its flights Thursday, four months after a plane flying to China disappeared. The latest information on Flight 370:
The Boeing 777 vanished March 8 while carrying 239 passengers and crew from Kuala Lumpur, Malaysia, to Beijing. While over the sea east of Malaysia, the plane made a sharp turn, crossed the Malaysian Peninsula and turned south over the Indian Ocean.
In late June, Australian officials said investigators believe MH370 flew on autopilot for hours before running out of fuel and crashing at sea.
Australian Transport Safety Bureau chief commissioner Martin Dolan said the assumption was that the autopilot was switched on intentionally, rather than automatically through a default system. But why, by whom and when during the flight remain unknown.
After an initial search was fruitless, the search area has shifted to an area about 1,800 kilometers (1,100 miles) off Australia's west coast.
Beginning in August, private contractors will use powerful side-scan sonar equipment capable of probing 7 kilometers (4.3 miles) deep to look for possible wreckage. The job is expected to take 12 months.
Two survey ships are mapping uncharted expanses of seabed in the search zone before the sonar scanning starts. Dolan said it was possible, but highly unlikely, that the mapping equipment could detect wreckage on the seafloor.
The earlier search zone was based on underwater sounds thought to be coming from airliner black boxes, but the sounds are now thought to have come from another source.