Malaysia Airlines Flight 370 (MH370/MAS370) was a scheduled international passenger flight that disappeared on Saturday, 8 March 2014, while flying from Kuala Lumpur International Airport, Malaysia to Beijing Capital International Airport, People's Republic of China. Air traffic control received the aircraft's last message at 01:20 MYT (17:20 UTC, 7 March) when it was over the South China Sea, less than an hour after takeoff. It was last plotted by military radar at 02:15 over the Andaman Sea, 320 kilometres (200 mi) northwest of Penang state in northwestern Malaysia. At 07:24, Malaysia Airlines (MAS) reported the flight missing. The aircraft, a Boeing 777-200ER, was carrying 12 Malaysian crew members and 227 passengers from 15 nations.
A multinational search effort, which became the largest and most expensive in history, began in the Gulf of Thailand and the South China Sea, where the flight's signal was lost on secondary surveillance radar, and was soon extended to the Strait of Malacca and Andaman Sea. The focus of the search shifted to the southern part of the Indian Ocean, west of Australia. An analysis of possible flight paths was conducted, identifying a 60,000 km2 (23,000 sq mi) search area, approximately 2,000 km (1,200 mi) west of Perth, Western Australia. The underwater search of this area began on 5 October 2014 and will last up to 12 months at a cost of A$60 million (approximately US$56 million or €41 million).
There has been no confirmation of any flight debris, and no crash site has been found, resulting in many unofficial theories about its disappearance. Analysis of these communications by multiple agencies has concluded that the flight ended in the southern Indian Ocean. On 24 March, the Malaysian government, noting that the final location determined by the satellite communication was far from any possible landing sites, concluded that "flight MH370 ended in the southern Indian Ocean."
At the time of its disappearance, and if the presumption of a loss of all lives aboard can be verified, MH370 would have been the deadliest aviation incident in the history of Malaysia Airlines and the deadliest involving a Boeing 777. MH370 was surpassed in both regards just 131 days later by the crash of another Malaysia Airlines Boeing 777, Flight 17, that was shot down over Ukraine on 17 July 2014, killing all 298 people aboard.