Malaysia Airlines Flight 370

=== Southeast Asia ===
{{anchor|initial search area}}[[File:MH370 initial search Southeast Asia.svg|thumb|upright=2<!-- large enough to be at least somewhat readable; in line with MOS:IMAGESYNTAX -->|The initial search area in Southeast Asia|alt=Map of southeast Asia with flight path and planned flight path of Flight 370 in the foreground. The search areas are depicted in a transparent grey colour. Search areas include the South China Sea and Gulf of Thailand near the location where Flight 370 disappeared from secondary radar, a rectangular area over the Malay Peninsula, and a region that covers roughly half of the Strait of Malacca and Andaman Sea.<!-- alt=A bathymetric map of Southeast Asia with the known flight path of Flight 370 shown. -->]]
The Kuala Lumpur Aeronautical Rescue Coordination Centre (ARCC) was activated at 05:30 MYT—four hours after communication was lost with the aircraft—to coordinate search and rescue efforts.<ref name="AW atc response" /> Search efforts began in the Gulf of Thailand and the South China Sea. On the second day of the search, Malaysian officials said that radar recordings indicated that Flight 370 may have turned around before vanishing from radar screens;<ref name="20140309washingtonpost" /> the search zone was expanded to include part of the [[Strait of Malacca]].<ref name="AutoVQ-63"/> On 12&nbsp;March, the chief of the [[Royal Malaysian Air Force]] announced that an unidentified aircraft—believed to be Flight 370—had travelled across the Malay peninsula and was last sighted on military radar {{convert|370|km|nmi mi|abbr=on}} northwest of the island of Penang; search efforts were subsequently increased in the Andaman Sea and Bay of Bengal.<ref name="AutoVQ-66"/>

Records of signals sent between the aircraft and a communications satellite over the Indian Ocean revealed that the plane had continued flying for almost six hours after its final sighting on Malaysian military radar. Initial analysis of these communications determined that Flight 370 was along one of two arcs—equidistant from the satellite—when its last signal was sent. On 15&nbsp;March, the same day upon which the analysis was disclosed publicly, authorities announced that they would abandon search efforts in the South China Sea, Gulf of Thailand, and Strait of Malacca in order to focus their efforts on the two corridors. The northern arc—from northern Thailand to Kazakhstan—was soon discounted, for the aircraft would have had to pass through heavily militarised airspace, and those countries claimed that their military radar would have detected an unidentified aircraft entering their airspace.<ref name="AutoVQ-68"/><ref name=TheGuardian-16032014>{{cite news |last1=Hodal |first1=Kate |title=Flight MH370: Malaysia asks for help in continued search for missing plane |url=https://www.theguardian.com/world/2014/mar/16/flight-mh370-malaysia-asks-help-missing-plane |access-date=4 November 2014 |work=The Guardian |location=Songkhla |date=16 March 2014 |url-access=registration |archive-date=3 November 2014 |archive-url=https://web.archive.org/web/20141103190237/http://www.theguardian.com/world/2014/mar/16/flight-mh370-malaysia-asks-help-missing-plane |url-status=live }}</ref><ref name="20140315nytblog"/>