Malaysia Airlines Flight 370

=== Response by air traffic control ===
[[File:MH370 ATC and air routes map.png|thumb|upright=1.8<!-- large enough to be readable on an average computer screen...per MOS:IMAGESYNTAX "Images containing important detail (for example, a map, diagram, or chart) may need larger sizes than usual to make them readable." -->|[[Flight Information Region]]s in the vicinity of where Flight 370 disappeared from secondary radar. Kuala Lumpur ACC provides ATC services for two routes, located within FIR Singapore, between Malaysia and Vietnam. (Air routes are depicted as roughly 5&nbsp;[[nautical mile|nmi]] / 8–10&nbsp;km wide, but vary in width, with some as wide as 20&nbsp;nmi / 35–40&nbsp;km.)|alt=Background is mostly water (blue), at the boundary of the South China Sea and Gulf of Thailand with the extreme southern tip of Vietnam in the upper right and a part of the Malay Peninsula at the Malaysia-Thailand border in the bottom left corner. Numerous air routes and a few waypoints are displayed, with some labelled, and the flight path of Flight 370 is shown in bright red. The boundaries of flight information regions are shown. The flight path goes from the bottom, just left of centre going north near air route R208, crossing from FIR Kuala Lumpur into FIR Singapore, but there is a note that air traffic control along R208 through FIR Singapore is provided by Kuala Lumpur ACC. A label notes where Flight 370 disappeared from primary radar just before turning slightly to the right at waypoint IGARI, which is along the boundary between FIR Singapore and FIR Ho Chi Minh, and the aircraft begins to follow route M765 towards waypoint BITOD. About halfway between IGARI and BITOD, Flight 370 makes sharp turn about 100° to the left, now heading northwest, and travels a short distance before making another left turn and heads southwest, crossing back over land near the Malaysia-Thailand border and flies close to air route B219.]]
At 01:38 MYT, Ho Chi Minh Area Control Centre (ACC) contacted Kuala Lumpur Area Control Centre to query the whereabouts of Flight 370 and informed Kuala Lumpur that ACC had not established verbal communication with Flight 370, which was last detected by radar at waypoint BITOD. The two centres exchanged four more calls during the next 20 minutes with no new information.<ref name="Preliminary report" /><ref name="AW atc response" />

At 02:03, Kuala Lumpur ACC relayed to Ho Chi Minh ACC information received from Malaysia Airlines' operations centre that Flight 370 was in Cambodian airspace. Ho Chi Minh ACC contacted Kuala Lumpur ACC twice in the following eight minutes asking for confirmation that Flight 370 was in Cambodian airspace.<ref name="Preliminary report" /> At 02:15, the watch supervisor at Kuala Lumpur ACC queried Malaysia Airlines' operations centre, which said that it could exchange signals with Flight 370 and that Flight 370 was in Cambodian airspace.<ref name="AW atc response" /> Kuala Lumpur ACC contacted Ho Chi Minh ACC to ask whether the planned flight path for Flight 370 passed through Cambodian airspace. Ho Chi Minh ACC responded that Flight 370 was not supposed to enter Cambodian airspace and that they had already contacted [[Phnom Penh]] ACC (which controls Cambodian airspace), which had no communication with Flight 370.<ref name="Preliminary report" /> Kuala Lumpur ACC contacted Malaysia Airlines' operations centre at 02:34, inquiring about the communication status with Flight 370, and were informed that Flight 370 was in a normal condition based on a signal download and that it was located at {{Coord|14|54|N|109|15|E|dim:1000km_region:VN}}.<ref name="AW atc response" /> Later, another Malaysia Airlines aircraft (Flight 386 bound for Shanghai) attempted, at the request of Ho Chi Minh ACC, to contact Flight 370 on the Lumpur Radar frequency – the frequency on which Flight 370 last made contact with Malaysian air traffic control – and on emergency frequencies. The attempt was unsuccessful.<ref name="Preliminary report" /><ref>{{cite web|title=Inquiry details controllers' hunt as MH370 vanished|url=http://www.flightglobal.com/news/articles/inquiry-details-controllers39-hunt-as-mh370-vanished-398793/|website=[[FlightGlobal]]|first=David|last=Kaminski-Morrow|date=1 May 2014|access-date=12 April 2015|archive-date=16 November 2018|archive-url=https://web.archive.org/web/20181116012804/https://www.flightglobal.com/news/articles/inquiry-details-controllers39-hunt-as-mh370-vanished-398793/|url-status=live}}</ref>

At 03:30, Malaysia Airlines' operations centre informed Kuala Lumpur ACC that the locations it had provided earlier were "based on flight projection and not reliable for aircraft positioning." Over the next hour, Kuala Lumpur ACC contacted Ho Chi Minh ACC asking whether they had signaled Chinese air traffic control. At 05:09, [[Singapore]] ACC was queried for information about Flight 370. At 05:20, an undisclosed official contacted Kuala Lumpur ACC requesting information about Flight 370; he opined that, based on known information, "MH370 never left Malaysian airspace."<ref name="Preliminary report" />

The watch supervisor at Kuala Lumpur ACC activated the Kuala Lumpur Aeronautical Rescue Coordination Centre (ARCC) at 05:30, more than four hours after communication was lost with Flight 370.<ref name="AW atc response">{{cite web |last1=Broderick |first1=Sean |title=First MH370 Report Details Confusion in Hours After Flight Was Lost |url=http://aviationweek.com/commercial-aviation/first-mh370-report-details-confusion-hours-after-flight-was-lost |website=Aviation Week |access-date=22 October 2014 |date=1 May 2014 |archive-date=31 May 2014 |archive-url=https://web.archive.org/web/20140531141316/http://aviationweek.com/commercial-aviation/first-mh370-report-details-confusion-hours-after-flight-was-lost |url-status=dead }}</ref> The ARCC is a command post at an Area Control Centre that coordinates [[Search and rescue|search-and-rescue]] activities when an aircraft is lost.