Malaysia Airlines Flight 370

== Search ==
{{Main|Search for Malaysia Airlines Flight 370}}
[[File:Ocean Shield deploys the Bluefin 21 underwater vehicle.jpg|thumb|right|[[ADV Ocean Shield|ADV ''Ocean Shield'']] deploys the [[Bluefin-21]] autonomous underwater vehicle, which conducted the seafloor sonar survey from 14&nbsp;April to 28&nbsp;May 2014|alt=Crane lowering the Bluefin 21 into the water]]
A search-and-rescue effort was launched in [[southeast Asia]] soon after the disappearance of Flight 370. Following the initial analysis of communications between the aircraft and a satellite, the surface search was moved to the southern Indian Ocean one week after the aircraft's disappearance. Between 18&nbsp;March and 28&nbsp;April, 19 vessels and 345 sorties by military aircraft searched over {{convert|4600000|sqkm|abbr=on}}.<ref name="SIO search facts statistics">{{cite web|title=Search for MH370 Facts and statistics Surface search of the southern Indian Ocean 17 March – 28 April 2014|url=http://www.jacc.gov.au/search/files/MH370_Facts_and_statistics-Surface_search_of_the_southern_Indian_Ocean.pdf|website=jacc.gov.au|publisher=Joint Agency Coordination Centre|access-date=5 December 2014|archive-date=11 March 2015|archive-url=https://web.archive.org/web/20150311183840/http://www.jacc.gov.au/search/files/MH370_Facts_and_statistics-Surface_search_of_the_southern_Indian_Ocean.pdf|url-status=live}}</ref> The final phase of the search was a [[bathymetric survey]] and sonar search of the sea floor, about {{convert|1800|km|nmi mi}} southwest of Perth, Western Australia.<ref name="NCA: ATSB October update">{{cite news|title=MH370 missing Malaysia Airlines plane: Search might be in wrong spot, investigators say|url=http://www.news.com.au/travel/travel-updates/mh370-missing-malaysia-airlines-plane-search-might-be-in-wrong-spot-investigators-say/story-fnizu68q-1227084277721|access-date=19 October 2014|publisher=[[News Corp Australia]]|website=[[News.com.au]]|first=Robyn|last=Ironside|date=9 October 2014|archive-date=19 October 2014|archive-url=https://web.archive.org/web/20141019090105/http://www.news.com.au/travel/travel-updates/mh370-missing-malaysia-airlines-plane-search-might-be-in-wrong-spot-investigators-say/story-fnizu68q-1227084277721|url-status=live}}</ref> With effect from 30&nbsp;March 2014, the search was coordinated by the [[Joint Agency Coordination Centre]] (JACC), an Australian government agency that was established specifically to manage the effort to locate and recover Flight 370, and which primarily involved the Malaysian, Chinese, and Australian governments.<ref name=JACC-about>{{cite web|title=About Us|url=http://www.jacc.gov.au/about.aspx|website=jacc.gov.au|publisher=Joint Agency Coordination Centre|access-date=5 December 2014|archive-date=10 March 2015|archive-url=https://web.archive.org/web/20150310181856/http://www.jacc.gov.au/about.aspx|url-status=live}}</ref>
[[File:US_Navy_P-8_Poseidon_taking_off_at_Perth_Airport.jpg|thumb|left|A [[Boeing P-8 Poseidon|P-8 Poseidon]] patrol aircraft of the [[US Navy]] departs [[Perth Airport]] to search for Flight 370, 22 March 2014]]
On 17 January 2017, the official search for Flight 370—which had proven to be the most expensive search operation in aviation history<ref name="CNN search expense">{{cite news |last1=Brown |first1=Sophie |date=16 June 2014 |title=MH370: How long will the search continue? |url=http://www.cnn.com/2014/06/16/world/asia/malaysia-airlines-how-long-will-search-continue/ |url-status=live |archive-url=https://web.archive.org/web/20141214111433/http://www.cnn.com/2014/06/16/world/asia/malaysia-airlines-how-long-will-search-continue/ |archive-date=14 December 2014 |access-date=15 November 2014 |work=CNN}}</ref><ref name="Newsweek search continues August 2014">{{cite news|title=The Hunt for Malaysia Airlines Flight MH370 Continues|url=http://www.newsweek.com/hunt-malaysia-airlines-flight-mh370-continues-263291|access-date=15 November 2014|work=Newsweek|agency=Reuters|date=6 August 2014|archive-date=14 December 2014|archive-url=https://web.archive.org/web/20141214100614/http://www.newsweek.com/hunt-malaysia-airlines-flight-mh370-continues-263291|url-status=live}}</ref>—was suspended after yielding no evidence of the aircraft other than some marine debris on the coast of Africa.<ref name="Search suspended">{{cite news|title=MH370: Families say search suspension for Malaysian plane 'irresponsible'|url=https://www.bbc.com/news/world-asia-38647365|access-date=17 January 2017|work=BBC News|date=17 January 2017|archive-date=17 January 2017|archive-url=https://web.archive.org/web/20170117081607/http://www.bbc.com/news/world-asia-38647365|url-status=live}}</ref><ref name="Bloomberg: search costs Jan 2017">{{cite news|last1=Whitley|first1=Angus|title=MH370 Search Ends to Leave Aviation's Biggest Mystery Unsolved|url=https://www.bloomberg.com/news/articles/2017-01-17/mh370-search-ends-to-leave-aviation-s-biggest-mystery-unsolved|access-date=17 January 2017|work=Bloomberg News|date=17 January 2017|quote=Australian investigators put the cost of the operation at A$180 million ($135 million).|archive-date=17 January 2017|archive-url=https://web.archive.org/web/20170117210708/https://www.bloomberg.com/news/articles/2017-01-17/mh370-search-ends-to-leave-aviation-s-biggest-mystery-unsolved|url-status=live}}</ref><ref name="CNN: search cost Jan 2017">{{cite news|last1=Perry|first1=Juliet|last2=Berlinger|first2=Joshua|title=MH370: Underwater search for missing plane suspended|url=http://www.cnn.com/2017/01/17/asia/mh370-search-suspended/index.html|access-date=17 January 2017|work=CNN|date=17 January 2017|quote=151 – Estimated cost of search in millions of U.S. dollars|archive-date=17 January 2017|archive-url=https://web.archive.org/web/20170117062931/http://www.cnn.com/2017/01/17/asia/mh370-search-suspended/index.html|url-status=live}}</ref><ref name="CT: search cost Jan 2017">{{cite news|title=After 3 years, MH370 search ends with no plane, few answers|url=https://www.chicagotribune.com/news/nationworld/ct-mh370-search-ends-20170116-story.html|access-date=17 January 2017|work=[[Chicago Tribune]]|date=17 January 2017|quote=The Joint Agency Coordination Center in Australia, which has helped lead the $160 million hunt for the Boeing 777 in remote waters west of Australia, said the search had officially been suspended after crews finished their fruitless sweep of the 120,000-square kilometer (46,000-square mile) search zone.|archive-date=17 January 2017|archive-url=https://web.archive.org/web/20170117224843/http://www.chicagotribune.com/news/nationworld/ct-mh370-search-ends-20170116-story.html|url-status=live}}</ref> The final ATSB report, published on 3&nbsp;October 2017, stated that the underwater search for the aircraft, {{as of|2017|June|30|lc=y}}, had cost a total of US$155 million (~${{Format price|{{Inflation|index=US-GDP|value=155000000|start_year=2017}}}} in {{Inflation/year|US-GDP}}). The underwater search accounted for 86% of this amount, [[bathymetry]] 10%, and [[programme management]] 4%. Malaysia had supported 58% of the total cost, Australia 32%, and China 10%.<ref name=Flight3Oct2017>{{cite news |url= https://www.flightglobal.com/news/articles/atsb-final-mh370-report-calls-for-more-precise-flig-441732/ |title= ATSB final MH370 report calls for more precise flight tracking |date= 3 October 2017 |first= Greg |last= Waldron |website= [[FlightGlobal]] |access-date= 3 October 2017 |archive-date= 3 October 2017 |archive-url= https://web.archive.org/web/20171003065523/https://www.flightglobal.com/news/articles/atsb-final-mh370-report-calls-for-more-precise-flig-441732/ |url-status= live }}</ref> The report also concluded that the location where the aircraft went down had been narrowed to an area of {{convert|25,000|sqkm|abbr=on}} by using satellite images and debris drift analysis.<ref>{{cite web|url=https://www.theguardian.com/world/2017/oct/03/mh370s-location-an-almost-inconceivable-mystery-final-report|title=MH370's location an 'almost inconceivable' mystery – final report|first=Christopher|last=Knaus|website=[[TheGuardian.com]]|date=3 October 2017|access-date=17 October 2017|archive-date=17 October 2017|archive-url=https://web.archive.org/web/20171017222854/https://www.theguardian.com/world/2017/oct/03/mh370s-location-an-almost-inconceivable-mystery-final-report|url-status=live}}</ref><ref name="ATSB Final Report AE-2014-054">{{cite web|url=https://www.atsb.gov.au/media/5773565/operational-search-for-mh370_final_3oct2017.pdf|title=ATSB Transport Safety Report, External Aviation Investigation, AE-2014-054: The Operational Search for MH370|publisher=[[Australian Transport Safety Bureau]]|date=3 October 2017|access-date=7 October 2017|format=Final report|archive-date=10 March 2020|archive-url=https://web.archive.org/web/20200310104643/https://www.atsb.gov.au/media/5773565/operational-search-for-mh370_final_3oct2017.pdf|url-status=dead}}</ref>

In January 2018, the private American marine-exploration company Ocean Infinity resumed the search for MH370 in the narrowed 25,000&nbsp;km<sup>2</sup> area, using the Norwegian ship ''[[Seabed Constructor]]''.<ref name="auto">{{cite news|url=https://www.telegraph.co.uk/news/2018/01/07/us-company-resumes-search-missing-flight-mh370/ |archive-url=https://ghostarchive.org/archive/20220110/https://www.telegraph.co.uk/news/2018/01/07/us-company-resumes-search-missing-flight-mh370/ |archive-date=10 January 2022 |url-access=subscription |url-status=live|title=US company resumes search for missing flight MH370|date=7 January 2018|work=The Telegraph|access-date=7 January 2018|agency=Associated Press|language=en-GB|issn=0307-1235}}{{cbignore}}</ref><ref name="auto1">{{cite news|url=https://www.cbsnews.com/news/malaysia-airlines-flight-370-ocean-infinity-new-search-for-missing-plane/|title=MH370: Private company to resume search for lost Malaysia Airlines plane|access-date=7 January 2018|archive-date=7 January 2018|archive-url=https://web.archive.org/web/20180107221527/https://www.cbsnews.com/news/malaysia-airlines-flight-370-ocean-infinity-new-search-for-missing-plane/|url-status=live}}</ref><ref name="InfinityWeek1"/><ref name="economist.com">{{cite news|url=https://www.economist.com/news/science-and-technology/21733399-swarm-submarine-drones-will-scour-depths-plane-fantastical-ship|title=A fantastical ship has set out to seek Malaysian Airlines flight 370|newspaper=The Economist|access-date=8 January 2018|archive-date=21 April 2018|archive-url=https://web.archive.org/web/20180421162746/https://economist.com/news/science-and-technology/21733399-swarm-submarine-drones-will-scour-depths-plane-fantastical-ship|url-status=live}}</ref> The search area was significantly extended during the course of the search, and by the end of May 2018, the vessel had searched a total area of more than {{convert|112000|sqkm|abbr=on}} using eight [[autonomous underwater vehicle]]s (AUVs).<ref name="InfinityWeek5">{{cite web|title=MH 370 Operational Search Update #5|url=https://oceaninfinity.com/wp-content/uploads/MH370-Search-Weekly-Report-5.pdf|website=oceaninfinity.com|publisher=Government of Malaysia|access-date=1 March 2018|archive-date=2 March 2018|archive-url=https://web.archive.org/web/20180302044511/https://oceaninfinity.com/wp-content/uploads/MH370-Search-Weekly-Report-5.pdf|url-status=dead}}</ref><ref name="conclusion">{{cite web |title= MH370 Conclusion of current search for Malaysian Airlines Flight MH370 |url= https://oceaninfinity.com/conclusion-current-search-malaysian-airlines-flight-mh370/ |website= oceaninfinity.com |publisher= oceaninfinity |access-date= 29 May 2018 |archive-url= https://web.archive.org/web/20180530035152/https://oceaninfinity.com/conclusion-current-search-malaysian-airlines-flight-mh370/ |archive-date= 30 May 2018 |url-status= dead }}</ref> The contract with the Malaysian government ended soon afterward, and the search was concluded without success on 9&nbsp;June 2018.<ref name="ended"/>

=== 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"/>

=== Southern Indian Ocean ===
[[File:MH370 SIO search.png|thumb|upright=2<!-- large enough to be at least somewhat readable; in line with MOS:IMAGESYNTAX -->|The shifting search zones for Flight 370 in the Southern Indian Ocean. The inset shows the path taken by the vessel ADV ''Ocean Shield'' operating a towed pinger locator, acoustic detections, and the sonar search. The underwater phase (both the wide area search and priority area) is shown in pink.|alt=A bathymetric map of the southeastern Indian Ocean and western Australia, with the locations of search zones, sonobouy drops, and calculated flight paths. An inset in the upper left shows the path of the ADV Ocean Shield which towed a Towed Pinger Locator and where it detected acoustic signals; the same inset also shows the seafloor sonar search performed in April–May 2014.]]
The emphasis of the search was shifted to the southern Indian Ocean west of Australia and within Australia's aeronautical and maritime Search and Rescue regions that extend to [[75th meridian east|75°E longitude]].<ref>{{cite web|title=Arrangements in Australia|url=https://www.amsa.gov.au/search-and-rescue/sar-in-australia/arrangements-in-australia/|website=Australian Maritime Safety Authority|access-date=12 November 2014|url-status=dead|archive-url=https://web.archive.org/web/20150224204938/http://www.amsa.gov.au/search-and-rescue/sar-in-australia/arrangements-in-australia/|archive-date=24 February 2015}}</ref><ref>{{cite web|title=National Search and Rescue Manual – June 2014 edition|url=http://natsar.amsa.gov.au/documents/NATSAR-Manual/Australian%20National%20SAR%20Manual%20June%202014%20FINAL.pdf|website=Australia Maritime Safety Authority|access-date=12 November 2014|page=231|archive-url=https://web.archive.org/web/20150412041944/http://natsar.amsa.gov.au/documents/NATSAR-Manual/Australian%20National%20SAR%20Manual%20June%202014%20FINAL.pdf|archive-date=12 April 2015|url-status=dead}}</ref> Accordingly, on 17&nbsp;March, Australia agreed to manage the search in the southern locus from [[Sumatra]] to the southern Indian Ocean.<ref name="20140317canberratimes"/><ref name="20140317thestar"/>

==== Initial search ====
From 18 to 27 March 2014, the search effort focused on a {{convert|315000|sqkm|abbr=on}} area about {{convert|2600|km|nmi mi|abbr=on}} southwest of Perth.<ref name="Search map 19 March"/> The search area, which Australian prime minister [[Tony Abbott]] called "as close to nowhere as it's possible to be", is renowned for its [[Roaring Forties|strong winds]], inhospitable climate, hostile seas, and deep ocean floors.<ref name="AutoVQ-17"/><ref name="Search map 18 March"/> Satellite imagery of the region was analysed;<ref>{{cite web|url=https://thewest.com.au/news/australia/perth-remote-sensing-firm-on-mh370-mission-ng-ya-368670|title=Perth remote sensing firm on MH370 mission|date=3 April 2014|website=The West Australian|access-date=10 December 2019|archive-date=7 December 2019|archive-url=https://web.archive.org/web/20191207035233/https://thewest.com.au/news/australia/perth-remote-sensing-firm-on-mh370-mission-ng-ya-368670|url-status=live}}</ref> several objects of interest and two possible debris fields were identified on images made between 16 and 26&nbsp;March. None of these possible objects were found by aircraft or ships.<ref name="BBC-satellite debris">{{cite news|title=Flight MH370: Images of ocean debris|url=https://www.bbc.com/news/world-asia-26662641|access-date=10 November 2014|publisher=BBC News|date=28 March 2014|archive-date=21 March 2015|archive-url=https://web.archive.org/web/20150321143007/http://www.bbc.com/news/world-asia-26662641|url-status=live}}</ref>

Revised estimates of the radar track and the aircraft's remaining fuel led to a move of the search {{convert|1100|km|nmi mi|abbr=on}} northeast of the previous area on 28&nbsp;March,<ref name="BBC_2014-03-28_b"/><ref name="NST(28 March)"/><ref name="CNN(28 March)"/> which was followed by another shift on 4 April.<ref name="JACC_2014-04-04_mr006">{{cite web|title=Search and recovery continues for Malaysian flight MH370 (4 April 2014 am)|url=http://www.jacc.gov.au/media/releases/2014/april/mr006.aspx|publisher=[[Joint Agency Coordination Centre]]|date=4 April 2014|access-date=6 May 2014|archive-date=5 May 2014|archive-url=https://web.archive.org/web/20140505071902/http://www.jacc.gov.au/media/releases/2014/april/mr006.aspx|url-status=live}}</ref><ref name="Search map 4 April">{{cite web|url=https://s3-ap-southeast-2.amazonaws.com/asset.amsa.gov.au/MH370+Day+18/Charts/2014_04_04_cumulative_search_handout.pdf|title=Incident 2014/1475 – search for Malaysia Airlines flight MH370 – area searched (4 April)|publisher=Australian Maritime Safety Authority|date=4 April 2014|access-date=12 April 2015|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304035159/https://s3-ap-southeast-2.amazonaws.com/asset.amsa.gov.au/MH370+Day+18/Charts/2014_04_04_cumulative_search_handout.pdf|url-status=live}}</ref> Between 2 and 17 April, an effort was made to detect the [[underwater locator beacon]]s (ULBs, informally known as "pingers") attached to the aircraft's [[flight recorder]]s, because the beacons' batteries were expected to expire around 7 April.<ref name="BBC_2014-03-31_a">{{cite news|last=Donnison|first=Jon|title=Malaysia flight MH370: No time limit on search, says Tony Abbott|url=https://www.bbc.co.uk/news/world-asia-26814929|work=BBC News|date=31 March 2014|access-date=8 May 2014|archive-date=3 April 2014|archive-url=https://web.archive.org/web/20140403095926/http://www.bbc.co.uk/news/world-asia-26814929|url-status=live}}</ref><ref name="British submarine">{{cite web |url=http://news.sky.com/story/1235477/royal-navy-submarine-joins-mh370-search |title=Royal Navy Submarine Joins MH370 Search |date=2 April 2014 |access-date=12 April 2015 |publisher=Sky News |archive-date=7 July 2015 |archive-url=https://web.archive.org/web/20150707163000/http://news.sky.com/story/1235477/royal-navy-submarine-joins-mh370-search |url-status=live }}</ref> Australian naval cutter [[ABFC Ocean Shield|ADV ''Ocean Shield'']], equipped with a [[towed pinger locator]] (TPL), joined China's ''[[Haixun 01]]'', equipped with a hand-held hydrophone, and the Royal Navy's [[HMS Echo (H87)|HMS ''Echo'']], equipped with a hull-mounted hydrophone, in the search.<ref name=ATSB />{{Rp|11–12}}<ref name="ATSB Final Report AE-2014-054"/>{{rp|36}}<ref name="BBC_2014-03-31_a"/><ref name=20140404IBT>{{cite web | url=http://www.ibtimes.com/malaysia-airlines-flight-mh370-towed-pinger-locators-deployed-underwater-hunt-black-1567381?ft=74gk7 | title=Malaysia Airlines Flight MH370: Towed Pinger Locators Deployed, Underwater Hunt For Black Box Launched With Hopes Of A Breakthrough | website=International Business Times | date=4 April 2014 | access-date=23 March 2018 | first1=Suman | last1=Varandani | archive-date=24 March 2018 | archive-url=https://web.archive.org/web/20180324041402/http://www.ibtimes.com/malaysia-airlines-flight-mh370-towed-pinger-locators-deployed-underwater-hunt-black-1567381?ft=74gk7 | url-status=live }}</ref><ref name="JACC_2014-04-04_mr007">{{cite web|title=Pinger locator equipment commences operation (4 April 2014)|url=http://www.jacc.gov.au/media/releases/2014/april/mr007.aspx|publisher=[[Joint Agency Coordination Centre]]|date=4 April 2014|access-date=6 May 2014|archive-date=31 May 2014|archive-url=https://web.archive.org/web/20140531173951/http://www.jacc.gov.au/media/releases/2014/april/mr007.aspx|url-status=live}}</ref> Operators considered the effort to have little chance of success<ref name="wday95224">{{cite web|url=http://www.wday.com/event/article/id/95224/group/News/ |title=Only days left before Malaysia airlines flight 370's black box dies |publisher=WDAY |date=30 March 2014 |archive-url=https://web.archive.org/web/20140407072117/http://www.wday.com/event/article/id/95224/group/News/ |archive-date=7 April 2014 |url-status=dead |access-date=13 July 2014 }}</ref> given the vast search area and the fact that a TPL can only search up to {{convert|50|mi2|order=flip|km2|abbr=on}} per day.<ref name="wday95224"/>

Between 4 and 8&nbsp;April, several acoustic detections were made that were close to the frequency and rhythm of the sound emitted by the flight recorders' ULBs; [[Search for Malaysia Airlines Flight 370#Underwater locator beacons|analysis of the acoustic detections]] determined that, although unlikely, the detections could have come from a damaged ULB.<ref name=ATSB />{{Rp|13}} A sonar search of the seafloor near the detections was carried out between 14&nbsp;April and 28&nbsp;May but yielded no sign of Flight 370.<ref name=ATSB />{{Rp|14}} In a March 2015 report, it was revealed that the battery of the ULB attached to Flight 370's flight data recorder may have expired in December 2012 and thus may not have been as capable of sending signals as would an unexpired battery.<ref>{{cite news |url=https://phys.org/news/2015-03-mh370-underwater-beacon-battery-expired.html |title=MH370 report: Underwater locator beacon battery had expired |work=phys.org |last=Ng |first=Eileen |date=8 March 2015 |access-date=7 July 2017 |archive-date=14 October 2017 |archive-url=https://web.archive.org/web/20171014234441/https://phys.org/news/2015-03-mh370-underwater-beacon-battery-expired.html |url-status=live }}</ref><ref>{{cite web |first=Samantha |last=Hawley |title=Malaysia Airlines MH370: Report finds battery powering locator beacon on black box expired in 2012, no red flags raised over crew or aircraft |date=8 March 2015 |access-date=8 March 2015 |website=Australian Broadcasting Corp. |url=http://www.abc.net.au/news/2015-03-08/mh370-report-says-black-box-locator-beacon-expired/6289462 |archive-date=8 March 2015 |archive-url=https://web.archive.org/web/20150308132611/http://www.abc.net.au/news/2015-03-08/mh370-report-says-black-box-locator-beacon-expired/6289462 |url-status=live }}</ref>

==== Underwater search ====
{{commons and category|Search for Malaysia Airlines Flight 370|Category:Search for Malaysia Airlines Flight 370}}
In late June 2014, details of the next phase of the search were announced;<ref>{{cite news|last1=Smyth|first1=Jamie|title=Search for Malaysia Airlines flight MH370 to resume in new area|url=http://www.ft.com/cms/s/0/912130e8-fd06-11e3-8ca9-00144feab7de.html#axzz3JS0bpHI4|access-date=18 November 2014|work=Financial Times|date=26 June 2014|archive-date=31 August 2014|archive-url=https://web.archive.org/web/20140831224222/http://www.ft.com/cms/s/0/912130e8-fd06-11e3-8ca9-00144feab7de.html#axzz3JS0bpHI4|url-status=live}}</ref> officials have called this phase the "underwater search" despite the previous seafloor sonar survey.<ref name=JACC-search>{{cite web|title=Search for MH370|url=http://www.jacc.gov.au/search/index.aspx|website=jacc.gov.au|publisher=Joint Agency Coordination Centre|access-date=14 December 2014|archive-date=20 June 2015|archive-url=https://web.archive.org/web/20150620180213/http://www.jacc.gov.au/search/index.aspx|url-status=live}}</ref> Continued refinement of the analysis of Flight 370's satellite communications identified a "wide area search" along the "7th arc"{{efn|name="7th arc"}} where Flight 370 was located when it last communicated with the satellite. The priority search area was in the southern extent of the wide area search.<ref name="Operational search update 8 Oct">{{cite web|title=MH370 Operational Search Update|url=http://www.jacc.gov.au/families/operational_reports/opsearch-update-20141008.aspx|website=Joint Agency Coordination Centre|access-date=12 November 2014|date=8 October 2014|archive-date=8 December 2014|archive-url=https://web.archive.org/web/20141208064243/http://www.jacc.gov.au/families/operational_reports/opsearch-update-20141008.aspx|url-status=live}}</ref> Some of the equipment used for the underwater search is most effective when towed {{convert|650|ft|order=flip|abbr=on}} above the seafloor at the end of a {{convert|6|mi|abbr=on|order=flip}} cable.<ref name="NYT-bathymetric survey">{{cite news|last1=Innis|first1=Michelle|title=Rugged Seabed Seen in New Maps Further Complicates Search for Malaysia Airlines Jet|url=https://www.nytimes.com/2014/10/07/world/asia/search-resumes-for-missing-malaysian-airliner.html|access-date=18 November 2014|work=The New York Times|date=6 October 2014|archive-date=27 October 2014|archive-url=https://web.archive.org/web/20141027123923/http://www.nytimes.com/2014/10/07/world/asia/search-resumes-for-missing-malaysian-airliner.html|url-status=live}}</ref> Available [[Bathymetry|bathymetric]] data for this region was of poor resolution, thus necessitating a bathymetric survey of the search area before the underwater phase began.<ref name="Operational search update 5 Nov">{{cite web|title=MH370 Operational Search Update|url=http://www.jacc.gov.au/families/operational_reports/opsearch-update-20141105.aspx|website=Joint Agency Coordination Centre|date=5 November 2014|access-date=5 December 2014|archive-date=11 March 2018|archive-url=http://webarchive.nla.gov.au/gov/20180311050517/http://www.jacc.gov.au/families/operational_reports/opsearch-update-20141105.aspx|url-status=live}}</ref> Commencing in May, the survey charted around {{convert|208000|sqkm|abbr=on}} of seafloor until 17&nbsp;December 2014, when it was suspended so that the ship conducting the survey could be mobilised in the underwater search.<ref name="JACC search update 7 Jan">{{cite web|title=MH370 Operational Search Update|date=7 January 2015|url=http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150107.aspx|website=Joint Agency Coordination Centre|access-date=8 January 2015|archive-date=10 January 2015|archive-url=https://web.archive.org/web/20150110070806/http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150107.aspx|url-status=live}}</ref>

The governments of Malaysia, China, and Australia made a joint commitment to thoroughly search {{convert|120000|sqkm|abbr=on}} of seafloor.<ref name="Operational search update 09 December 2015">{{cite web|title=MH370 Operational Search Update|url=http://jacc.gov.au/families/operational_reports/opsearch-update-20151209.aspx|website=JACC|access-date=9 December 2015|date=9 December 2015|archive-date=10 December 2015|archive-url=https://web.archive.org/web/20151210213135/http://jacc.gov.au/families/operational_reports/opsearch-update-20151209.aspx|url-status=live}}</ref> This phase of the search, which began on 6&nbsp;October 2014,<ref name="Operational search update 8 Oct" /> used three vessels equipped with towed deep-water vehicles that use side-scan sonar, multi-beam echo sounders, and video cameras to locate and identify aircraft debris.<ref name="WSJ-5th phase begins">{{cite news|last=Stewart|first=Robb M|title=Malaysia Airlines Flight 370 Search Reboots|url=https://online.wsj.com/articles/malaysia-airlines-flight-370-search-reboots-1412578236|access-date=8 October 2014|work=The Wall Street Journal|date=6 October 2014|archive-date=9 October 2014|archive-url=https://web.archive.org/web/20141009010007/http://online.wsj.com/articles/malaysia-airlines-flight-370-search-reboots-1412578236|url-status=live}}</ref> A fourth vessel participated in the search between January and May 2015, using an [[autonomous underwater vehicle|AUV]] to search areas that could not be effectively searched using equipment on the other vessels.<ref name="14 Jan 2015 Search update">{{cite web|title=MH370 Operational Search Update|url=http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150114.aspx|website=JACC|access-date=2 February 2015|date=14 January 2015|quote=Fugro Supporter is expected to arrive in the search area and commence search activities in late January. Fugro Supporter has been equipped with a Kongsberg HUGIN 4500 autonomous underwater vehicle (AUV). The AUV will be used to scan those portions of the search area that cannot be searched effectively by the equipment on the other search vessels.|archive-date=19 January 2015|archive-url=https://web.archive.org/web/20150119230517/http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150114.aspx|url-status=live}}</ref><ref name="JACC search update 28 Jan 2015">{{cite web|title=MH370 Operational Search Update|date=28 January 2015|url=http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150128.aspx|website=JACC|access-date=1 February 2015|archive-date=30 January 2015|archive-url=https://web.archive.org/web/20150130023357/http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150128.aspx|url-status=live}}</ref><ref name="13 May 2015 search update">{{cite web|title=MH370 Operational Search Update|url=http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150513.aspx|website=JACC|access-date=2 June 2015|date=13 May 2015|archive-date=17 May 2015|archive-url=https://web.archive.org/web/20150517124216/http://www.jacc.gov.au/families/operational_reports/opsearch-update-20150513.aspx|url-status=live}}</ref> Following the discovery of the flaperon on Réunion, the [[Australian Transport Safety Bureau]] (ATSB) reviewed its drift calculations for debris from the aircraft and, according to the JACC, was satisfied that the search area was still the most likely crash site.<ref name="Operational search update 5 August 2015" /> Reverse drift modelling of the debris, to determine its origin after 16 months, also supported the underwater search area, although this method is very imprecise over long periods.<ref name="Operational search update 5 August 2015" /> On 17&nbsp;January 2017, the three countries jointly announced the suspension of the search for Flight 370.<ref name="Search suspended"/><ref name="MH370 Joint Communique">{{cite web|title=MH370 Joint Communique|url=http://jacc.gov.au/media/communiques/2017/com005.aspx|website=JACC|date=17 January 2017|access-date=20 January 2017|archive-date=17 January 2017|archive-url=https://web.archive.org/web/20170117171757/http://jacc.gov.au/media/communiques/2017/com005.aspx|url-status=live}}</ref>

===2018 search===
On 17 October 2017, Dutch-based [[Fugro]] and American company [[Ocean Infinity]] offered to resume the search for the aircraft.<ref>{{cite news|url=https://www.theguardian.com/world/2017/oct/17/mh370-companies-approach-malaysia-restarting-new-search-for-plane|title=MH370: three companies approach Malaysia over restarting search for plane|agency=Reuters|date=17 October 2017|work=The Guardian|access-date=17 October 2017|url-access=registration|archive-date=17 October 2017|archive-url=https://web.archive.org/web/20171017045944/https://www.theguardian.com/world/2017/oct/17/mh370-companies-approach-malaysia-restarting-new-search-for-plane|url-status=live}}</ref> In January 2018, Ocean Infinity announced that it was planning to resume the search in the narrowed {{convert|25000|sqkm|abbr=on}} area. The search attempt was approved by the Malaysian government, provided that payment would be made only if the wreckage were<!--subjunctive--> found.<ref name="auto"/><ref name="auto1"/> Ocean Infinity chartered the Norwegian ship ''[[Seabed Constructor]]'' to perform the search.<ref name="economist.com"/>

In late January, it was reported that the [[Automatic identification system|AIS tracking system]] had detected the vessel reaching the search zone on 21&nbsp;January. The vessel then started moving to {{coord|-35.6|92.8|type:landmark_scale:10000000|name=CSIRO crash area}}, the most likely crash site according to the drift study by the [[Commonwealth Scientific and Industrial Research Organisation]] (CSIRO).<ref name="star23"/> The planned search area of "site&nbsp;1", where the search began, was {{convert|33012|sqkm|abbr=on}}, while the extended search area covered a further {{convert|48500|sqkm|abbr=on}}.<ref name="InfinityWeek1">{{cite web|title=MH370 Operational Search Update #1|url=https://oceaninfinity.com/wp-content/uploads/MH370-Search-Weekly-Report-1.pdf|website=oceaninfinity.com|publisher=Government of Malaysia|access-date=15 February 2018|archive-date=8 February 2018|archive-url=https://web.archive.org/web/20180208174245/https://oceaninfinity.com/wp-content/uploads/MH370-Search-Weekly-Report-1.pdf|url-status=dead}}</ref> In April, a report by Ocean Infinity revealed that "site&nbsp;4", farther northeast along the 7th arc,{{efn|name="7th arc"|The 7th arc is a line on the map of possible positions where the aircraft went down due to fuel exhaustion.<ref>{{cite web |url=https://www.atsb.gov.au/mh370-pages/the-search/maps/ |title=The Search – Maps – The Seventh Arc |work=[[Australian Transport Safety Bureau]] |access-date=2 October 2019 |archive-date=2 October 2019 |archive-url=https://web.archive.org/web/20191002203401/https://www.atsb.gov.au/mh370-pages/the-search/maps/ |url-status=live }}</ref><ref>{{cite web |url=https://www.flightglobal.com/news/articles/new-analysis-helps-refine-mh370-search-area-419681/ |title=New analysis helps refine MH370 search area |date=3 December 2015 |first=Ellis |last=Taylor |website=[[FlightGlobal]] |access-date=2 October 2019 |archive-date=2 October 2019 |archive-url=https://web.archive.org/web/20191002204516/https://www.flightglobal.com/news/articles/new-analysis-helps-refine-mh370-search-area-419681/ |url-status=live }} 7th arc is indicated in Figure 1 (by a pink line).</ref> It corresponds to the seventh and final handshake with the tracking satellite at 08:19.<ref>{{cite web |url=https://www.atsb.gov.au/mh370-pages/the-search/faqs/ |title=Frequently asked questions: Why is the seventh satellite handshake' or arc so important? |work=[[Australian Transport Safety Bureau]] |quote=The seventh handshake was the last communications MH370 had with the satellite... we are confident that the point where the aircraft ran out of fuel lies on the arc delineated by the seventh handshake. |access-date=2 October 2019 |archive-date=2 October 2019 |archive-url=https://web.archive.org/web/20191002203401/https://www.atsb.gov.au/mh370-pages/the-search/faqs/ |url-status=live }}</ref>}} had been added to the search plan.<ref name="InfinityWeek12">{{cite web|title=MH 370 Operational Search Update #12|url=https://oceaninfinity.com/wp-content/uploads/MH370-Search-Weekly-Report-12.pdf|website=oceaninfinity.com|publisher=Government of Malaysia|access-date=20 April 2018|archive-date=23 April 2018|archive-url=https://web.archive.org/web/20180423170022/https://oceaninfinity.com/wp-content/uploads/MH370-Search-Weekly-Report-12.pdf|url-status=dead}}</ref> By the end of May 2018, the vessel had searched a total area of over {{convert|112000|sqkm|abbr=on}}, using eight [[autonomous underwater vehicle|AUVs]];<ref name="InfinityWeek5"/><ref name="conclusion"/> all areas of "site&nbsp;1" (including areas beyond that originally planned for "site&nbsp;1"), "site&nbsp;2", and "site&nbsp;3" had been searched.<ref name="InfinityWeek18">{{cite web|title=MH 370 Operational Search Update #18|url=http://mh370.gov.my/en/mh370-underwater-search-2018?download=150:29-may-2018-english-version|website=mh370.gov.my|publisher=Government of Malaysia|access-date=29 May 2018|archive-date=20 September 2019|archive-url=https://web.archive.org/web/20190920215828/http://mh370.gov.my/en/mh370-underwater-search-2018?download=150:29-may-2018-english-version|url-status=dead}}</ref> The final phase of the search was conducted in "site&nbsp;4" in May 2018,<ref name="InfinityWeek18"/> "before the weather limits Ocean Infinity's ability to continue working this year."<ref>{{cite web |url= https://oceaninfinity.com/update-search-missing-malaysian-airlines-flight-mh370 |title= Update on search for Missing Malaysian Airlines Flight MH370 |work= OceanInfinity.com |date= 30 April 2018 |access-date= 30 July 2018 |archive-date= 12 June 2018 |archive-url= https://web.archive.org/web/20180612140738/https://oceaninfinity.com/update-search-missing-malaysian-airlines-flight-mh370/ |url-status= dead }}</ref> Malaysia's new transport minister [[Loke Siew Fook]] announced on 23&nbsp;May 2018 that the search for MH370 would conclude at the end of the month.<ref name="loke">{{cite news |url=https://edition.cnn.com/2018/05/23/asia/mh370-search-to-end-intl/index.html |title=MH370 search to end on May 29 after four years |first=Angela |last=Dewan |work=CNN |date=23 May 2018 |access-date=24 May 2018 |archive-date=23 May 2018 |archive-url=https://web.archive.org/web/20180523202136/https://edition.cnn.com/2018/05/23/asia/mh370-search-to-end-intl/index.html |url-status=live }}</ref> Ocean Infinity confirmed on 31&nbsp;May that its contract with the Malaysian government had ended,<ref name=perthnow>{{cite web|url=https://www.perthnow.com.au/news/transport/mh370-hunt-continues-for-few-more-days-ng-s-1864235|title=MH370 hunt continues for few more days|date=1 June 2018|access-date=30 July 2018|archive-date=12 June 2018|archive-url=https://web.archive.org/web/20180612142250/https://www.perthnow.com.au/news/transport/mh370-hunt-continues-for-few-more-days-ng-s-1864235|url-status=live}}</ref><ref>{{cite web |url=https://www.news.com.au/travel/travel-updates/incidents/mh370-search-ship-seabed-constructor-not-ready-to-stop-yet/news-story/d20ba9dc35fddf95e8a92770c5fe5ffe?from=rss-basic |title=MH370 search: It's not over till it's over |access-date=30 July 2018 |archive-date=4 December 2021 |archive-url=https://web.archive.org/web/20211204112133/https://www.news.com.au/travel/travel-updates/incidents/mh370-search-ship-seabed-constructor-not-ready-to-stop-yet/news-story/d20ba9dc35fddf95e8a92770c5fe5ffe?from=rss-basic |url-status=live }}</ref> and it was reported on 9&nbsp;June 2018 that the Ocean Infinity search had come to an end.<ref name="ended">{{cite web |url=https://changingtimes.media/2018/06/09/mh370-ocean-infinity-search-ends-amid-calls-for-new-disclosures-and-further-investigation/ |title=MH370: Ocean Infinity search ends amid calls for new disclosures and further investigation |date=8 June 2018 |access-date=30 July 2018 |archive-date=12 June 2018 |archive-url=https://web.archive.org/web/20180612142211/https://changingtimes.media/2018/06/09/mh370-ocean-infinity-search-ends-amid-calls-for-new-disclosures-and-further-investigation/ |url-status=live }}</ref> Ocean-floor mapping data collected during the search have been donated to the [[Nippon Foundation]]–[[General Bathymetric Chart of the Oceans|GEBCO]] Seabed 2030 Project, to be incorporated into the global map of the ocean floor.<ref>{{cite web |url= https://www.marinetechnologynews.com/news/ocean-infinity-donates-seabed-561884 |title= Ocean Infinity Donates Data to Seabed Mapping Project |date= 21 June 2018 |access-date= 30 July 2018 |archive-date= 21 June 2018 |archive-url= https://web.archive.org/web/20180621201418/https://www.marinetechnologynews.com/news/ocean-infinity-donates-seabed-561884 |url-status= live }}</ref><ref>{{cite web|url=https://seabed2030.gebco.net/resources_for_journalists/documents/ocean_infinity_press_release.pdf|title=Ocean Infinity donates 120,000 square kilometres of data from search for missing Malaysian airliner to The Nippon Foundation-GEBCO Seabed 2030 Project|date=21 June 2018|publisher=[[Nippon Foundation]]|format=press release|access-date=22 June 2018|archive-date=22 June 2018|archive-url=https://web.archive.org/web/20180622192734/https://seabed2030.gebco.net/resources_for_journalists/documents/ocean_infinity_press_release.pdf|url-status=dead}}</ref>

In March 2019, in the wake of the fifth anniversary of the disappearance, the Malaysian government stated that it was willing to look at any "credible leads or specific proposals" regarding a new search.<ref>{{cite web|url=https://www.theguardian.com/world/2019/mar/07/mh370-search-glimmer-of-hope-remains-with-malaysia-open-to-fresh-hunt|title=MH370: relatives call for 'serious commitment' from Malaysia to find plane|first=Naaman|last=Zhou|date=7 March 2019|work=The Guardian|url-access=registration|access-date=23 March 2019|archive-date=7 March 2019|archive-url=https://web.archive.org/web/20190307045422/https://www.theguardian.com/world/2019/mar/07/mh370-search-glimmer-of-hope-remains-with-malaysia-open-to-fresh-hunt|url-status=live}}</ref> Ocean Infinity stated that it was ready to resume the search on the same no-find, no-fee basis, believing that it would benefit from the experience that it had gained from its search for the wreck of Argentinian submarine [[ARA San Juan (S-42)|ARA ''San Juan'']] and [[bulk carrier]] ship ''[[Stellar Daisy]].'' Ocean Infinity believed that the most probable location was still somewhere along the 7th arc around the area identified previously and upon which its 2018 search was based.<ref>{{cite web|url=https://www.airlineratings.com/news/mh370-ocean-infinity-stands-ready-resume-search/|title=MH370: Ocean Infinity stands ready to resume search|first=Steve|last=Creedy|date=4 March 2019|access-date=23 March 2019|archive-date=23 March 2019|archive-url=https://web.archive.org/web/20190323111055/https://www.airlineratings.com/news/mh370-ocean-infinity-stands-ready-resume-search/|url-status=live}}</ref>

=== Potential 2024 search ===
In March 2022, Ocean Infinity committed to resuming its search in 2023 or 2024, pending approval by the Malaysian government.<ref name=":0">{{cite web |last=Thomas |first=Geoffrey |date=6 March 2022 |title=Ocean Infinity commits to new search for MH370 in 2023 or 2024 |url=https://www.airlineratings.com/news/ocean-infinity-commits-new-search-mh370-2023-2024/ |access-date=22 March 2022 |website=Airline Ratings |language=en-AU |archive-date=6 March 2022 |archive-url=https://web.archive.org/web/20220306100807/https://www.airlineratings.com/news/ocean-infinity-commits-new-search-mh370-2023-2024/ |url-status=live }}</ref> In 2023, Ocean Infinity was reviewing data from their previous 2018 search to ensure nothing was missed. CEO Oliver Plunkett hoped to resume the search in the summer of 2023 using Ocean Infinity's new ''Armada'' vessel. The transportation minister of Malaysia, [[Wee Ka Siong]], requested credible new evidence from Ocean Infinity in order to resume the search, which Plunkett is allegedly in possession of.<ref>{{Cite web |last=Iskandat |first=Iylia Marsya |date=5 March 2023 |title=Ocean Infinity wants to resume MH370 search |url=https://www.nst.com.my/news/nation/2023/03/886151/ocean-infinity-wants-resume-mh370-search |access-date=28 March 2023 |website=New Straits Times |archive-date=28 March 2023 |archive-url=https://web.archive.org/web/20230328220919/https://www.nst.com.my/news/nation/2023/03/886151/ocean-infinity-wants-resume-mh370-search |url-status=live }}</ref> Claims of yet-to-be-identified new evidence has incited victims' families to further push for another search.<ref>{{Cite news |last=Kelly |first=Cait |date=7 March 2023 |title=Families of MH370 victims' push for another search as technology firm says it has new evidence |language=en-GB |work=The Guardian |url=https://www.theguardian.com/world/2023/mar/08/families-of-mh370-victims-push-for-another-search-as-technology-firm-says-it-has-new-evidence |access-date=31 March 2023 |issn=0261-3077 |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331005736/https://www.theguardian.com/world/2023/mar/08/families-of-mh370-victims-push-for-another-search-as-technology-firm-says-it-has-new-evidence |url-status=live }}</ref>

In March 2024, days before the tenth anniversary of the disappearance, Malaysia said it would consult with Australia about collaborating on another expedition by the Ocean Infinity team.<ref>{{Cite news |last=Azhar |first=Danial |last2=Leong |first2=Mandy |date=2024-03-03 |title=Malaysia says MH370 search must go on, 10 years after plane vanished |url=https://www.reuters.com/world/asia-pacific/malaysia-says-mh370-search-must-go-10-years-after-plane-vanished-2024-03-03/ |access-date=2024-03-04 |work=Reuters |language=en |archive-date=3 March 2024 |archive-url=https://web.archive.org/web/20240303190817/https://www.reuters.com/world/asia-pacific/malaysia-says-mh370-search-must-go-10-years-after-plane-vanished-2024-03-03/ |url-status=live }}</ref><ref>{{Cite web |last=Nazzaro |first=Miranda |date=2024-03-03 |title=Malaysia signals it may revive search for missing flight MH370, a decade later |url=https://thehill.com/policy/transportation/4505455-malaysia-revive-search-flight-mh370-decade-later/ |access-date=2024-03-04 |website=The Hill |language=en-US |archive-date=4 March 2024 |archive-url=https://web.archive.org/web/20240304014840/https://thehill.com/policy/transportation/4505455-malaysia-revive-search-flight-mh370-decade-later/ |url-status=live }}</ref><ref>{{Citation |title='The search must go on': Malaysian government 'committed' to finding MH370 |url=https://www.youtube.com/watch?v=AKkiLplVNrA |access-date=2024-03-04 |language=en |archive-date=4 March 2024 |archive-url=https://web.archive.org/web/20240304014846/https://www.youtube.com/watch?v=AKkiLplVNrA |url-status=live }}</ref>