Malaysia Airlines Flight 370

== <span id="Disappearance">Flight and disappearance</span> ==
[[File:MH370 flight path with English labels.png|thumb|left<!-- left alignment prevents stacking this image, external media, and radar image -->|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." -->|Known flight path taken by Flight 370 (red), derived from [[primary radar|primary]] (military) and [[Secondary surveillance radar|secondary]] ([[Air traffic control|ATC]]) radar data|alt=Map of southeast Asia that shows the southern tip of Vietnam in the upper right (northeast), Malay Peninsula (southern part of Thailand, part of Malaysia, and Singapore), upper part of Sumatra island, most of the Gulf of Thailand, southwestern part of the South China Sea, Strait of Malacca, and part of the Andaman Sea. The flight path of Flight 370 is shown in red, going from KLIA (lower centre) on a straight path northeast, then (in the upper right side) turning to the right before making a sharp turn left and flies in a path that resembles a wide "V" shape (about a 120–130° angle) and ends in the upper left side. Labels note where the last ACARS message was sent just before Flight 370 crossed from Malaysia into the South China Sea, last detection was made by secondary radar before the aircraft turned right, and where final detection by military radar was made at the point where the path ends.]]
Flight 370 was a scheduled flight in the early morning of Saturday, 8&nbsp;March 2014, from Kuala Lumpur, Malaysia, to Beijing, China. It was one of two daily flights operated by Malaysia Airlines from its hub at [[Kuala Lumpur International Airport]] (KLIA) to [[Beijing Capital International Airport]]—scheduled to depart at 00:35 [[Time in Malaysia|local time]] (MYT; [[UTC+08:00]]) and arrive at 06:30 [[Time in China|local time]] (CST; UTC+08:00).<ref>{{cite web|title=Tweet|url=https://twitter.com/flightradar24/status/442118255511998464|website=Twitter|publisher=[[Flightradar24]]|access-date=24 October 2014|date=7 March 2014|archive-date=31 May 2014|archive-url=https://web.archive.org/web/20140531120037/https://twitter.com/flightradar24/status/442118255511998464|url-status=live}}</ref><ref name="Second daily flight cancelled" /> On board were two pilots, 10 cabin crew, 227 passengers, and {{convert|14296|kg|abbr=on}} of cargo.<ref name="Interim report-March 2015">{{cite web|author=|first=|date=8 March 2014|title=Factual Information, Safety Investigation: Malaysia Airlines MH370 Boeing 777-200ER (9M-MRO)|url=http://mh370.mot.gov.my/download/FactualInformation.pdf|url-status=dead|archive-url=https://web.archive.org/web/20150309093347/http://mh370.mot.gov.my/download/FactualInformation.pdf|archive-date=9 March 2015|access-date=9 March 2015|website=|publisher=Malaysia Ministry of Transport|location=Malaysia}}</ref>{{Rp|1, 12, 30}}

The planned flight duration was 5&nbsp;hours and 34&nbsp;minutes, which would consume an estimated {{convert|37200|kg|lb|abbr=on}} of [[jet fuel]]. The aircraft carried {{convert|49100|kg|lb}} of fuel, including reserves, allowing an endurance of 7&nbsp;hours and 31&nbsp;minutes. The extra fuel was enough to divert to [[Alternative airport|alternate airports<!-- Wikilinked because of an issue with semantics, which was an issue raised in the talk page discussion "Alternate is not a synonym of alternative". The wikilink is preferable to using a footnote to explain an "alternate airport" or using "alternative airport", which is not used in aviation. -->]]—[[Jinan Yaoqiang International Airport]] and [[Hangzhou Xiaoshan International Airport]]—which would require {{convert|4800|kg|lb|abbr=on}} or {{convert|10700|kg|lb|abbr=on}}, respectively, to reach from Beijing.<ref name="Interim report-March 2015" />{{Rp|1, 30}}

=== Departure ===
At 00:42 MYT, Flight 370 took off from runway 32R,<ref name="Interim report-March 2015" />{{Rp|1}} and was cleared by [[air traffic control]] (ATC) to climb to [[flight level]] 180{{efn|name=Flight level|Aircraft altitude is given as feet above sea level and measured, at higher altitudes, by air pressure, which [[Atmospheric pressure#Altitude variation|declines]] as altitude above sea level increases. Using a [[International Standard Atmosphere|standard sea level pressure]] and formula, the nominal altitude of a given air pressure can be determined—referred to as the "pressure altitude". A [[flight level]] is the pressure altitude in hundreds of feet. For example, flight level 350 corresponds to an altitude where air pressure is {{convert|179|mmHg|abbr=on}}, which is nominally {{convert|35000|ft|abbr=on|sigfig=3}} but does not indicate the true altitude.}}—approximately {{convert|18000|ft|sigfig=2}}<!-- since result is 4 digits, using 3 significant figures seems too precise. 18000 ft=5486.4m...so using 5500m as opposed to 5490 is not a huge difference -->—on a direct path to navigational [[waypoint]] IGARI (located at {{coord|6|56|12|N|103|35|6|E|type:landmark_scale:4000000|name=Waypoint IGARI}}). Voice analysis has determined that the first officer communicated with ATC while the flight was on the ground and that the Captain communicated with ATC after departure.<ref name="Interim report-March 2015" />{{Rp|21}} Shortly after departure, the flight was transferred from the airport's ATC to "Lumpur Radar" air traffic control on [[Airband|frequency]] 132.6&nbsp;MHz. ATC over peninsular Malaysia and adjacent waters is provided by the Kuala Lumpur [[Area Control Centre]] (ACC); Lumpur Radar is the name of the frequency [[Air traffic control#En route, center, or area control|used for ''en route'' air traffic]].<ref name=FIR-Malaysia /> At 00:46, Lumpur Radar cleared Flight 370 to flight level 350{{efn|name=Flight level}}—approximately {{convert|35000|ft|abbr=on|sigfig=3}}. At 01:01, Flight 370's crew reported to Lumpur Radar that they had reached flight level 350, which they confirmed again at 01:08.<ref name="Interim report-March 2015" />{{Rp|1–2}}<ref name="Preliminary report">{{cite news|title=Documents: Preliminary report on missing Malaysia Airlines Flight 370|url=http://www.cnn.com/interactive/2014/04/world/malaysia-flight-documents/|publisher=Malaysia Department of Civil Aviation|via=CNN|access-date=22 October 2014|archive-date=1 May 2014|archive-url=https://web.archive.org/web/20140501200705/http://www.cnn.com/interactive/2014/04/world/malaysia-flight-documents/|url-status=live}}</ref>

=== Communication lost ===
{{external media
| video1 = [https://www.youtube.com/watch?v=q13aTqdMAFw ATC conversations with Flight 370] Audio recordings of conversations between ATC and Flight 370 from pre-departure to final contact (00:25–01:19).
}}
The aircraft's final transmission was an automated position report, sent using the [[Aircraft Communications Addressing and Reporting System]] (ACARS) protocol at 01:06&nbsp;MYT.<ref name=ATSB />{{Rp|2}}<ref name="Press Con"/><ref name="Ground log">{{cite web |title=Signalling Unit Log for (9M-MRO) Flight MH370 |archive-url=https://web.archive.org/web/20160304040818/http://www.dca.gov.my/mainpage/MH370%20Data%20Communication%20Logs.pdf |archive-date=4 March 2016 |url-status=dead |url=http://www.dca.gov.my/mainpage/MH370%20Data%20Communication%20Logs.pdf |publisher=Inmarsat/Malaysia Department of Civil Aviation |access-date=29 June 2014}}</ref>{{RP|36}} Among the data provided in this message was the total fuel remaining: {{convert|43800|kg|lb|abbr=on}}.<ref name="ATSB Flight path update">{{cite web|title=MH370 – Flight Path Analysis Update|url=http://www.atsb.gov.au/media/5163181/AE-2014-054_MH370%20-FlightPathAnalysisUpdate.pdf|website=Australian Transport Safety Bureau|access-date=15 November 2014|date=8 October 2014|publisher=[[Australian Transport Safety Bureau]]|archive-date=18 September 2019|archive-url=https://web.archive.org/web/20190918020649/https://www.atsb.gov.au/media/5163181/AE-2014-054_MH370%20-FlightPathAnalysisUpdate.pdf|url-status=dead}}</ref>{{Rp|9}} The last verbal signal to air traffic control occurred at 01:19:30, when Captain Zaharie acknowledged a transition from Lumpur Radar to [[Ho Chi Minh City|Ho Chi Minh]] [[Area Control Centre|ACC]]:{{efn|name=Singapore FIR|Responsibility for air traffic control is partitioned geographically, by international agreements, into [[flight information region]]s (FIRs). Although the airspace at the point where Flight 370 was lost is part of the Singapore FIR, the Kuala Lumpur ACC had been delegated responsibility to provide air traffic control services to aircraft in that part of its FIR.<ref name=FIR-Malaysia />{{Rp|13}}}}<ref name="Interim report-March 2015" />{{Rp|2, 21}}<ref name="Preliminary report" /><ref name="Guardian Transcript"/>

{{blockquote|Lumpur Radar: "Malaysian three seven zero, contact Ho Chi Minh one two zero decimal nine. Good night."<br />
Flight 370: "Good night. Malaysian three seven zero."}}

The crew was expected to signal ATC in Ho Chi Minh City as the aircraft passed into Vietnamese airspace, just north of the point where contact was lost.<ref name="AutoVQ-3"/><ref name="AutoVQ-4"/> The captain of another aircraft attempted to contact the crew of Flight 370 shortly after 01:30, using the [[Aircraft emergency frequency|international air distress<!-- (IAD) --> frequency]], to relay Vietnamese air traffic control's request for the crew to contact them; the captain said he was able to establish communication, but heard only "mumbling" and static.<ref name="nst-pilot"/> Calls made to Flight 370's cockpit at 02:39 and 07:13 were unanswered, but acknowledged by the aircraft's [[satellite data unit]].<ref name=ATSB />{{Rp|18}}<ref name="Ground log" />{{Rp|40}}

=== <span id="Radar returns">Radar</span> ===
[[File:MH370 radar.jpeg|thumb|right|Data from the Malaysian military's primary radar show Flight 370 (green) crossing the Strait of Malacca and Andaman Sea to where it was last detected by radar. The left of the two segments of the flight track follows air route N571 between waypoints VAMPI and MEKAR; the white circle appears to highlight a section where the aircraft was not tracked by radar.|alt=Brown background with white lines, dots, and labels depicting air routes, waypoints, and airports. Label in the top of the image reads: "Military radar plot from Pulau Perak to last plot at 02:22H." Green specks form a trail from bottom centre to left centre that was Flight 370. As the caption explains, the path is in two parts, with a white circle around the blank area between them and appears to highlight a section where the aircraft was not tracked by radar. Label at left end of flight path reads: "Time-02:22H 295R 200nm from Butterworth AB"]]
At 01:20:31 MYT, Flight 370 was observed on radar at the Kuala Lumpur ACC as it passed the navigational [[Waypoint#In aviation|waypoint]] IGARI ({{coord|6|56|12|N|103|35|6|E|display=inline|dim:1000km|name=Waypoint IGARI}}) in the [[Gulf of Thailand]]; five seconds later, the [[Secondary surveillance radar#Mode S|Mode-S]] symbol disappeared from radar screens.<ref name="Interim report-March 2015" />{{Rp|2}} At 01:21:13, Flight 370 disappeared from the radar screen at Kuala Lumpur ACC and was lost at about the same time on radar at Ho Chi Minh ACC, which reported that the aircraft was at the nearby waypoint BITOD.<ref name="Interim report-March 2015" />{{Rp|2}}<ref name="Preliminary report" /> Air traffic control uses secondary radar, which relies on a signal emitted by a [[Transponder (aeronautics)|transponder]] on each aircraft; therefore, the [[ADS-B]] transponder was no longer functioning on Flight 370 after 01:21. The final transponder data indicated that the aircraft was flying at its assigned [[Cruise (flight)|cruise]] altitude of flight level 350{{efn|name=Flight level}} and was travelling at {{convert|471|kn|km/h mph}} [[true airspeed]].<ref name="20140311theaviationist"/> There were few clouds around this point, and no rain or lightning nearby.<ref name="Interim report-March 2015" />{{Rp|33–36}} Later analysis estimated that Flight 370 had {{convert|41500|kg|lb|abbr=on}} of fuel when it disappeared from secondary radar.<ref name="Interim report-March 2015" />{{Rp|30}}

At the time that the transponder stopped functioning, the Malaysian military's primary radar showed Flight 370 turning right, but then<!-- Source says: "At 1721:13 UTC [0121:13 MYT] the Military radar showed the radar return of MH370 turning right but almost immediately making a constant left turn to a South Westerly direction." --> beginning a left turn to a southwesterly direction.<ref name="Interim report-March 2015" />{{Rp|3}} From 01:30:35 until 01:35, military radar showed Flight 370 at {{convert|35700|ft|abbr=on}}{{efn|Heights given by primary radar are actual altitudes, unlike the pressure altitudes provided by secondary radar.}} on a 231° magnetic heading, with a ground speed of {{convert|496|kn|km/h mph}}. Flight 370 continued across the Malay Peninsula, fluctuating between {{convert|31000|and|33000|ft|abbr=on}} in altitude.<ref name="Interim report-March 2015" />{{Rp|3}} A civilian primary radar at [[Sultan Ismail Petra Airport]] with a {{convert|60|nmi|abbr=on}} range made four detections of an unidentified aircraft between 01:30:37 and 01:52:35; the tracks of the unidentified aircraft are "consistent with those of the military data".{{efn|The interim report released by Malaysia during March 2015 states: "All the primary aircraft targets that were recorded by the DCA radar are consistent with those of the military data that were made available to the Investigation Team." The report does not ''explicitly''<!-- emphasis of this term is important and should be italicised per MOS:EMPHASIS --> state that the unidentified aircraft was Flight 370.<ref name="Interim report-March 2015" />{{Rp|3–4}}}}<ref name="Interim report-March 2015" />{{Rp|3–4}} At 01:52<!-- 01:52:35 MYT-->, Flight 370 was detected passing just south of the island of Penang. From there, the aircraft flew across the Strait of Malacca, passing close to the waypoint VAMPI, and [[Pulau Perak]] at 02:03<!-- 02:02:59 MYT -->, after which it flew along air route N571 to waypoints MEKAR, NILAM, and possibly IGOGU.<ref name=ATSB />{{Rp|3, 38}} The last known radar detection, from a point near the limits of Malaysian military radar, was at 02:22, {{convert|10|nmi|abbr=on}} after passing waypoint MEKAR<ref name="Interim report-March 2015" />{{Rp|3, 7}} (which is {{convert|237|nmi|abbr=on}} from Penang) and {{convert|247.3|nmi|abbr=on}} northwest of Penang airport at an altitude of {{convert|29500|ft|abbr=on}}.<ref name="AutoVQ-2"/><ref name="AutoVQ-66"/>

Countries were reluctant to release information collected from military radar because of sensitivity about revealing their capabilities. [[Indonesia]] has an [[early-warning radar]] system, but its ATC radar did not register any aircraft with the transponder code used by Flight 370, despite the aircraft possibly having flown near, or over, the northern tip of Sumatra.<ref name="Interim report-March 2015" />{{Rp|4}}<ref name="Preliminary report" /> Indonesian military radar tracked Flight 370 earlier when ''en route'' to waypoint IGARI before the transponder is thought to have been turned off, but did not provide information on whether it was detected afterwards.<ref name="Interim report-March 2015" />{{Rp|4}}<ref name=WSJ-radar /> Thailand and Vietnam also detected Flight 370 on radar before the transponder stopped working. The radar position symbols for the transponder code used by Flight 370 vanished after the transponder is thought to have been turned off.<ref name="Interim report-March 2015" />{{Rp|4–5}} Vietnam's deputy minister of transport Pham Quy Tieu stated that Vietnam had noticed MH370 turning back toward the west and that its operators had twice informed Malaysian authorities the same day on 8&nbsp;March.<ref>{{cite news |url=https://www.straitstimes.com/asia/se-asia/vietnam-says-it-told-malaysia-that-missing-plane-mh370-had-turned-back |title=Vietnam says it told Malaysia that missing plane MH370 had turned back |work=[[The Straits Times]] |date=12 March 2014 |access-date=21 April 2019 |archive-date=5 March 2021 |archive-url=https://web.archive.org/web/20210305231839/https://www.straitstimes.com/asia/se-asia/vietnam-says-it-told-malaysia-that-missing-plane-mh370-had-turned-back |url-status=live }}</ref> Thai military radar detected an aircraft that might have been Flight 370, but it is not known at what time the last radar contact was made, and the signal did not include identifying data.<ref>{{cite news |url=https://www.smh.com.au/world/missing-malaysia-airlines-plane-thailand-gives-radar-data-10-days-after-plane-lost-20140318-hvk7i.html |title=Missing Malaysia Airlines plane: Thailand gives radar data 10 days after plane lost |work=[[The Sydney Morning Herald]] |last=Doksone |first=Thanyarat |date=19 March 2014 |access-date=7 July 2017 |archive-date=30 August 2017 |archive-url=https://web.archive.org/web/20170830155007/http://www.smh.com.au/world/missing-malaysia-airlines-plane-thailand-gives-radar-data-10-days-after-plane-lost-20140318-hvk7i.html |url-status=live }}</ref> Also, the flight was not detected by Australia's conventional system<ref>{{cite web |url=https://www.sbs.com.au/news/fragment/how-could-australian-radar-miss-flight-mh370 |title=How could Australian radar miss flight MH370? |date=26 March 2014 |publisher=[[Special Broadcasting Service]] |archive-url=https://web.archive.org/web/20170319111421/https://www.sbs.com.au/news/fragment/how-could-australian-radar-miss-flight-mh370 |archive-date=19 March 2017}}</ref> or its long-range [[Jindalee Operational Radar Network|JORN]] [[over-the-horizon radar]] system, which has an official range of {{cvt|3000|km}}; the latter was not in operation on the night of the disappearance.<ref name="JORN-FAQ" />

=== Satellite communication resumes ===
{{Further|Malaysia Airlines Flight 370 satellite communications}}
At 02:25 MYT, the aircraft's satellite communication system sent a "log-on request" message—the first message since the [[ACARS]] transmission at 01:07—which was relayed by satellite to a ground station, both operated by satellite telecommunications company [[Inmarsat]]. After logging on to the network, the satellite data unit aboard the aircraft responded to hourly status requests from Inmarsat and two ground-to-aircraft telephone calls, at 02:39 and 07:13, both unanswered by the cockpit.<ref name=ATSB />{{Rp|18}}<ref name="Ground log" /> The final status request and aircraft acknowledgement occurred at 08:10, about 1 hour and 40 minutes after the flight was scheduled to arrive in Beijing. The aircraft sent a log-on request at 08:19:29, which was followed, after a response from the ground station, by a "log-on acknowledgement" message at 08:19:37. The log-on acknowledgement is the last piece of data received from Flight 370. The aircraft did not respond to a status request from Inmarsat at 09:15.<ref name=ATSB /><ref name="Ground log" /><ref name="Inmarsat(26 March)" /><ref name=Fox-Inmarsat />

=== 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.

=== {{Anchor|Assumed loss}}Presumed loss ===
Malaysia Airlines issued a media statement at 07:24 MYT, one hour after the scheduled arrival time of the flight at Beijing, stating that communication with the flight had been lost by Malaysian ATC at 02:40 and that the government had initiated search-and-rescue operations;<ref name="MAS press statements 8–17 March"/> the time when contact was lost was later corrected to 01:21.<ref name="MAS press statements 8–17 March"/> Neither the crew nor the aircraft's communication systems relayed a [[distress signal]], indications of bad weather, or technical problems before the aircraft vanished from radar screens.<ref name="20140312avweek"/>

On 24 March, Malaysian Prime Minister [[Najib Razak]] appeared before media at 22:00 local time to give a statement regarding Flight 370, during which he announced that he had been briefed by the [[Air Accidents Investigation Branch]] that it and Inmarsat (the satellite data provider) had concluded that the airliner's last position before it disappeared was in the southern Indian Ocean. As no places exist where it could have landed, the aircraft must therefore have crashed into the sea.<ref name="20140324theguardian"/>

Just before Najib spoke at 22:00 MYT, an emergency meeting was called in Beijing for relatives of Flight 370 passengers.<ref name="20140324theguardian"/> Malaysia Airlines announced that Flight 370 was assumed lost with no survivors. It notified most of the families in person or via telephone, and some received an [[Short Message Service|SMS]] (in English and Chinese) informing them that the aircraft likely had crashed with no survivors.<ref name="BBC_2014-03-24"/><ref name="20140324theguardian"/><ref name="20140324independent"/><ref name="20140324nytimes"/>

On 29 January 2015, the director general of the [[Civil Aviation Authority of Malaysia|Department of Civil Aviation Malaysia]], Azharuddin Abdul Rahman, announced that the status of Flight 370 would be changed to an "accident", in accordance with the [[Chicago Convention on International Civil Aviation]], and that all passengers and crew are presumed to have lost their lives.<ref name="Official accident declaration">{{cite web |last1=Rahma |first1=Azharuddin Abdul |title=Announcement on MH370 by Director General |url=http://www.mh370.gov.my/images/phocadownload/doa_announcement.pdf |website=Official Site for MH370 |publisher=Department of Civil Aviation Malaysia |access-date=31 January 2015 |date=29 January 2015 |archive-url=https://web.archive.org/web/20160416081240/http://www.mh370.gov.my/images/phocadownload/doa_announcement.pdf |archive-date=16 April 2016 |url-status=dead }}</ref>

If the official assumption is confirmed, Flight 370 was, at the time of its disappearance, the deadliest aviation incident in the history of Malaysian Airlines, surpassing the 1977 hijacking and crash of [[Malaysian Airline System Flight 653]] that killed all 100 passengers and crew aboard, and the deadliest involving a Boeing 777, surpassing [[Asiana Airlines Flight 214]] (three fatalities).<ref name="Guardian-safe"/><ref name="reuters-safe"/> In both of those categories, Flight 370 was surpassed 131 days later by [[Malaysia Airlines Flight 17]], another Boeing 777-200ER, which was shot down on 17&nbsp;July 2014, killing all 298 people aboard.<ref name="CNN MH370-MH17"/>

=== Reported sightings ===
The news media reported several sightings of an aircraft fitting the description of the missing Boeing 777. For example, on 19&nbsp;March 2014, [[CNN]] reported that witnesses including fishermen, an oil rig worker, and people on the [[Kuda Huvadhoo]] atoll in the Maldives saw the missing airliner. A fisherman claimed to have seen an unusually low-flying aircraft off the coast of [[Kota Bharu]], while an oil-rig worker {{convert|186|mi|km}} southeast of [[Vung Tau]] claimed he saw a "burning object" in the sky that morning, a claim credible enough for the Vietnamese authorities to send a search-and-rescue mission, and Indonesian fishermen reported witnessing an aircraft crash near the [[Malacca Straits]].<ref>{{cite news |last1=Martinez |first1=Michael |title=Flying low? Burning object? Ground witnesses claim they saw Flight 370 |url=http://www.cnn.com/2014/03/19/world/asia/malaysia-airlines-plane-ground-witnesses/ |access-date=19 May 2015 |agency=CNN |date=19 March 2014 |archive-date=1 October 2020 |archive-url=https://web.archive.org/web/20201001061103/https://www.cnn.com/2014/03/19/world/asia/malaysia-airlines-plane-ground-witnesses/ |url-status=live }}</ref> Three months later, ''[[The Daily Telegraph]]'' reported that a British woman sailing in the Indian Ocean claimed to have seen an aircraft on fire.<ref>{{cite news |last1=Pearlman |first1=Jonathan |title=Malaysia Airlines plane search: British yachtswoman 'saw MH370 on fire' |url=https://www.telegraph.co.uk/news/worldnews/asia/malaysia/10872261/Malaysia-Airlines-plane-search-British-yachtswoman-saw-MH370-on-fire.html |archive-url=https://ghostarchive.org/archive/20220110/https://www.telegraph.co.uk/news/worldnews/asia/malaysia/10872261/Malaysia-Airlines-plane-search-British-yachtswoman-saw-MH370-on-fire.html |archive-date=10 January 2022 |url-access=subscription |url-status=live |access-date=19 May 2015 |newspaper=The Telegraph |date=3 June 2014}}{{cbignore}}</ref>