Editing Amelia Earhart (section)

== World flight in 1937 ==
[[File:Amelia Earhart - GPN-2002-000211.jpg|thumb|Amelia Earhart standing in front of the Lockheed Electra in which she disappeared in July 1937]]

=== Planning ===

Early in 1936, Earhart started planning to fly around the world; if she succeeded, she would become the first woman to do so. Although others had flown around the world, Earhart's flight would be the longest at 29,000 miles (47,000&nbsp;km) because it followed a roughly equatorial route. Earhart planned to court publicity along the route to increase interest in a planned book about the expedition.<ref>[https://www.nytimes.com/1936/04/20/archives/miss-earhart-to-get-flying-laboratory-purdue-announces-50000-fund.html "Miss Earhart to get 'Flying Laboratory'."] {{webarchive|url=https://web.archive.org/web/20130520205402/http://select.nytimes.com/gst/abstract.html?res=F20A1FF83C5E167B93C2AB178FD85F428385F9 |date=May 20, 2013 }} ''The New York Times'', April 20, 1936, p. 3. accessed: September 23, 2017.</ref>

[[Purdue University]] established the Amelia Earhart Fund for Aeronautical Research and gave $50,000 ({{Inflation|US|50000|1936|fmt=eq|r=-4}}) to fund the purchase of a Lockheed Electra 10E airplane.{{sfn|Goldstein|Dillon|1997|p=150}} In July 1936, [[Lockheed Aircraft Company]] built the airplane, which was fitted with extra fuel tanks and other extensive modifications.<ref>[http://www.pacificwrecks.com/aircraft/electra/1055.html "Lockheed Model 10E Electra c/n: 1055 Reg: NR16020."] {{webarchive|url=https://web.archive.org/web/20120710172423/http://pacificwrecks.com/aircraft/electra/1055.html |date=July 10, 2012 }} ''PacificWrecks.com'', January 5, 2011. accessed: September 23, 2017.</ref> Earhart dubbed the twin-engine monoplane her "flying laboratory". The plane was built at Lockheed's plant in [[Burbank, California]], and after delivery, it was hangared at the nearby Mantz's United Air Services.{{sfn|Long|Long|1999|p=59}}

Earhart chose [[Harry Manning]] as her navigator; he had been the captain of the {{SS|President Roosevelt|1921|2}}, the ship that had transported Earhart from Europe in 1928.{{sfn|Goldstein|Dillon|1997|p=150}} Manning was also a pilot and a skilled radio operator who knew [[Morse code]].{{sfn|Long|Long|1999|p=62}}

[[File:Amelia Earhart and Fred Noonan.jpg|thumb|upright=0.75|Amelia Earhart and her navigator Fred Noonan]]

The original plan was a two-person crew: Earhart would fly and Manning would navigate. During a flight across the US that included Earhart, Manning, and Putnam, Earhart flew using landmarks; she and Putnam knew where they were. Manning did a navigation fix that alarmed Putnam, because Manning made a minor navigational error that put them in the wrong state; they were flying close to the state line, but Putnam was still concerned.<ref>{{harvtxt|Long|Long|1999|pp=60–61}}: Manning "passed a note to Amelia in the cockpit giving a position in southern Kansas when they were actually in northern Oklahoma. Amelia realized they were only a few miles south of the Kansas border; in reality, the position wasn't all that far off. G. P. took the worst possible view and expressed concern because Manning didn't even have them in the right state."</ref> Sometime later, Putnam and Mantz arranged a night flight to test Manning's navigational skill.{{sfn|Long|Long|1999|p=64}} Under poor navigational conditions, Manning's position was off by {{convert|20|miles|km|abbr=out}}. [[Elgen Long|Elgen M.]] and Marie K. Long considered Manning's performance reasonable, because it was within an acceptable error of {{convert|30|miles|km|abbr=out}}, but Mantz and Putnam wanted a better navigator.{{sfn|Long|Long|1999|p=65}}

Through contacts in the Los Angeles aviation community, [[Fred Noonan]] was chosen as a second navigator, because there were significant additional factors that had to be dealt with while using [[celestial navigation]] for aircraft.{{sfn|Long|Long|1999|p=65}}{{sfn|Post|Gatty|1931|pp=45–56}} Noonan, a licensed ship's captain, was experienced in both marine and [[air navigation|flight navigation]]; he had recently left [[Pan American World Airways]] (Pan Am), where he established most of the company's [[China Clipper]] seaplane routes across the Pacific. Noonan had also been responsible for training Pan American's navigators to fly the route between [[San Francisco]] and [[Manila]].{{sfn|Grooch|1936|pp=177, 189}} Under the original plans, Noonan would navigate from Hawaii to Howland Island—a difficult portion of the flight—then Manning would continue with Earhart to Australia, and she would proceed on her own for the remainder of the project.{{citation needed|date=June 2024}}

=== Abandoned first attempt ===
On March 17, 1937, Earhart and her crew set out on the first leg of her round-the-world flight, but they abandoned this attempt after a non-fatal crash that damaged the aircraft. The first leg of this attempt was between Oakland, California, and Honolulu, Hawaii. The crew were Earhart, Noonan, Manning, and Mantz, who was acting as Earhart's technical advisor. The propeller hubs' variable pitch mechanisms had problems, so the aircraft was taken to the U.S. Navy's [[Naval Auxiliary Landing Field Ford Island|Luke Field]] facility at [[Pearl Harbor]] for servicing. The flight resumed three days later from Luke Field, with Earhart, Noonan and Manning on board. The next destination was [[Howland Island]], a small island in the Pacific. Manning, the radio operator, had made arrangements to use [[radio direction finding]] to home in to the island. The flight never left Luke Field; during the takeoff run, there was an uncontrolled [[ground loop (aviation)|ground-loop]], the forward landing gear collapsed, both propellers hit the ground, and the plane skidded on its belly. The cause of the crash is not known; some witnesses at Luke Field, including an Associated Press journalist, said they saw a tire blow.{{sfn|Rich|1989|p=245}} Earhart earlier thought the Electra's right tire had blown and the right landing gear had collapsed. Some sources, including Mantz, cited an error by Earhart.{{sfn|Rich|1989|p=245}} With the aircraft severely damaged, the attempt was abandoned and the aircraft was shipped to [[Burbank, California#Aviation|Lockheed Burbank]], California, for repairs.{{sfn|Leder|1989|p=48}}

===Second attempt===

[[File:Amelia Earhart flight route.svg|right|thumb|The planned flight route]]

While the Electra was being repaired, Earhart and Putnam secured additional funds and prepared for a second attempt, in which they would fly west to east. The second attempt began with an unpublicized flight from Oakland to [[Miami]], Florida, and after arriving there, Earhart announced her plans to circumnavigate the globe. The flight's opposite direction was partly the result of changes in global wind-and-weather patterns along the planned route since the earlier attempt.{{citation needed|date=June 2024}}

Manning, the only skilled radio operator, had left the crew, which now consisted of Noonan and Earhart. The pair departed Miami on June 1 and after numerous stops in South America, Africa, the Indian subcontinent, and Southeast Asia, arrived at [[Lae]], [[Territory of New Guinea|New Guinea]], on June 29, 1937. At this stage, about 22,000 miles (35,000&nbsp;km) of the journey had been completed. The remaining 7,000 miles (11,000&nbsp;km) would be over the Pacific.{{citation needed|date=June 2024}}

{| class="wikitable collapsible collapsed" style="margin: 1em auto 1em auto;"
|+ '''Earhart's&nbsp;1937&nbsp;flight&nbsp;route'''
!width=12em| Date !! Departure city<ref>Waitt, Ted. [http://www.searchforamelia.org/ "The Search for Amelia."] {{webarchive|url=https://web.archive.org/web/20130703131716/http://searchforamelia.org/ |date=July 3, 2013 }} ''Waitt Institute for Discovery''. accessed: June 19, 2013.</ref> !! Arrival city !! [[Nautical miles|Nautical<br />miles]] !! Notes{{sfn|Earhart|1937}}
|-
| {{nowrap|May 20, 1937}} || [[Oakland, California|Oakland]], [[California]] || [[Burbank, California|Burbank]], California ||style="text-align:right"| 283 ||
|-
| May 21, 1937 || Burbank, California || [[Tucson, Arizona|Tucson]], [[Arizona]] ||style="text-align:right"| 393 ||
|-
| May 22, 1937 || Tucson, Arizona || [[New Orleans]], [[Louisiana]] ||style="text-align:right"| 1070 || Arrived at [[Lakefront Airport]]<ref>{{cite web |url=https://www.nola.com/news/politics/new-orleans-art-deco-lakefront-airport-terminal-sheds-its-cold-war-shell/article_6b45a635-4385-5e0b-8127-0cac7b660241.html |title=New Orleans' Art Deco Lakefront Airport terminal sheds its Cold War shell |website=nola.com |date=September 25, 2013 |access-date = February 3, 2024 |url-status=live |archive-url = https://web.archive.org/web/20171215223900/http://www.nola.com/politics/index.ssf/2013/09/new_orleans_art_deco_lakefront.html |archive-date = December 15, 2017 |df=mdy-all}}</ref>
|-
| May 23, 1937 || New Orleans, Louisiana || [[Miami]], [[Florida]] ||style="text-align:right"| 586 ||Arrived at [[Opa-locka, Florida#Miami Municipal Airport|Miami Municipal Airport]].<ref>
* {{cite web |title=Miami Municipal Airport / Amelia Earhart Field and All-American Airport / Masters Field / Naval & Marine Corps Air Station Miami |url=https://www.pbase.com/airlinerphotos/airports_oldmiami |website=Sunbird Photos by Don Boyd |access-date=1 February 2024}}
* {{cite web |title=Then: Navy Municipal (former Miami Municipal) and Naval Air Station Miami Master Field (former All-American Airport) |url=https://pbase.com/donboyd/image/90390413 |website=Memories of Old Hialeah, Old Miami and Old South Florida Photo Galleries |access-date=1 February 2024}}
* {{cite web |last1=Estock |first1=Debra |title=Opa-locka, Florida |url=https://sofl.cooperatornews.com/article/opa-locka-florida |website=CooperatorNews South Florida |access-date=1 February 2024 |date=June 2016}}
* {{cite web| url= http://www.crazedfanboy.com/npcr/laflapcr192.html |title= The History of Aviation in Florida| website=Crazedfanboy.com | publisher=La Floridiana| date= November 24–30, 2003 |first= William |last= Moriaty |access-date= 8 April 2006}}</ref>
|-
| June 1, 1937 || Miami, Florida || [[San Juan, Puerto Rico|San Juan]], [[Puerto Rico]] ||style="text-align:right"| 908 ||
|-
| June 2, 1937 || San Juan, Puerto Rico || [[Caripito]], [[Venezuela]] ||style="text-align:right"| 492 || Out of [[Fernando Luis Ribas Dominicci Airport|Isla Grande Airport]]
|-
| June 3, 1937 || Caripito, Venezuela || [[Paramaribo]], [[Surinam (Dutch colony)|Surinam]] ||style="text-align:right"| 610 ||
|-
| June 4, 1937 || Paramaribo, Surinam || [[Fortaleza]], [[Vargas Era|Brazil]] ||style="text-align:right"| 1142 ||
|-
| June 5, 1937 || Fortaleza, Brazil || [[Natal, Rio Grande do Norte|Natal]], Brazil ||style="text-align:right"| 235 ||
|-
| June 7, 1937 || Natal, Brazil || [[Saint-Louis, Senegal|Saint-Louis]], [[French West Africa]] <small>(now [[Senegal]])</small> ||style="text-align:right"| 1727 || [[Transatlantic flight]]
|-
| June 8, 1937 || Saint-Louis, Fr.W. Africa || [[Dakar]], Fr.W. Africa <small>(now [[Senegal]])</small> ||style="text-align:right"| 100 ||
|-
| June 10, 1937 || Dakar, Fr.W. Africa || [[Gao]], [[French Sudan]] ||style="text-align:right"| 1016 ||
|-
| June 11, 1937 || Gao, French Sudan || [[N'Djamena|Fort-Lamy]], [[French Equatorial Africa]] <small>(now N'Djamena, [[Chad]])</small> ||style="text-align:right"| 910 ||
|-
| June 12, 1937 || Fort-Lamy, Fr.Eq. Africa || [[El Fasher]], [[Anglo-Egyptian Sudan]] ||style="text-align:right"| 610 ||
|-
| June 13, 1937 || El Fasher, Anglo-Egyptian Sudan || [[Khartoum]], Anglo-Egyptian Sudan ||style="text-align:right"| 437 ||
|-
| June 13, 1937 || Khartoum, Anglo-Egyptian Sudan || [[Massawa]], [[Italian East Africa]] <small>(now [[Eritrea]])</small> ||style="text-align:right"| 400 ||
|-
| June 14, 1937 || Massawa, Italian East Africa || [[Assab]], Italian East Africa <small>(now [[Eritrea]])</small>  ||style="text-align:right"| 241 ||
|-
| June 15, 1937 || Assab, Italian East Africa || [[Karachi]], [[British Raj|British India]] ||style="text-align:right"| 1627 || First ever non-stop flight from the Red Sea to India
|-
| June 17, 1937 || Karachi, British India || [[Kolkata|Calcutta]], British India ||style="text-align:right"| 1178 ||
|-
| June 18, 1937 || Calcutta, British India || [[Akyab]], [[British rule in Burma|Burma]] ||style="text-align:right"| 291 ||
|-
| June 19, 1937 || Akyab, Burma || [[Yangon|Rangoon]], Burma ||style="text-align:right"| 268 ||
|-
| June 20, 1937 || Rangoon, Burma || [[Bangkok]], [[Thailand|Siam]] ||style="text-align:right"| 315 ||
|-
| {{nowrap|June 20, 1937}} || Bangkok, Siam || [[Singapore in the Straits Settlements|Singapore]], [[Straits Settlements]] ||style="text-align:right"| 780 ||
|-
| June 21, 1937|| Singapore, Straits Settlements || [[Bandung|Bandoeng]], [[Dutch East Indies]] <small>(now [[Indonesia]])</small> ||style="text-align:right"| 541 ||
|-
| June 25, 1937 || Bandoeng, Dutch East Indies || [[Surabaya|Soerabaia]], Dutch East Indies <small>(now [[Indonesia]])</small> ||style="text-align:right"| 310 || Delayed due to [[monsoon]]
|-
| June 25, 1937 || Soerabaia, Dutch East Indies || Bandoeng, Dutch East Indies ||style="text-align:right"| 310 || Returned for repairs, Earhart ill with [[dysentery]]
|-
| June 26, 1937 || Bandoeng, Dutch East Indies || Soerabaia, Dutch East Indies ||style="text-align:right"| 310 ||
|-
| June 27, 1937 || Soerabaia, Dutch East Indies || [[Kupang|Koepang]], Dutch East Indies <small>(now [[Indonesia]])</small> ||style="text-align:right"| 668 ||
|-
| June 28, 1937 || Koepang, Dutch East Indies || [[Darwin, Northern Territory|Darwin]], [[Australia]] ||style="text-align:right"| 445 || Direction finder repaired, parachutes removed and sent home
|-
| June 29, 1937 || Darwin, Australia || [[Lae]], [[Territory of New Guinea|New Guinea]] <small>(now [[Papua New Guinea]])</small> ||style="text-align:right"| 1012 ||
|-
| July 2, 1937 || Lae, New Guinea || [[Howland Island]], [[American Equatorial Islands]] ||style="text-align:right"| 2223<ref>{{Cite web|url=https://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Worldflight/2ndattemptroute.html|title=Intended Route to Howland, 2nd Attempt|website=tighar.org|access-date=April 15, 2021|archive-date=April 15, 2021|archive-url=https://web.archive.org/web/20210415203511/https://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Worldflight/2ndattemptroute.html|url-status=live}}</ref> || Did not arrive
|-
| July 3, 1937 || Howland Island || [[Honolulu]], [[Territory of Hawaii|Hawaii]] ||style="text-align:right"| 1900 || Planned leg
|-
| July 4, 1937 || Honolulu, Hawaii || Oakland, California ||style="text-align:right"| 2400 || Planned leg
|}

===Flight between Lae and Howland Island===
[[File:Earhart locations.png|thumb|Earhart's flight was intended to be from [[Lae Airfield]] to [[Howland Island]], a trip of {{convert|2556|miles|nmi km|-2}}.]]

On <time datetime="1937-07-02T00:00Z">July 2, 1937,</time> at 10:00 am local time (12:00 am [[GMT]]), Earhart and Noonan took off from [[Lae Airfield]] in the heavily loaded Electra.<ref>[http://gc.kls2.com/airport/AYLA.OLD Lae Airfield (AYLA)] {{webarchive|url=https://web.archive.org/web/20121018133354/http://gc.kls2.com/airport/AYLA.OLD |date=October 18, 2012 }} at Great Circle Mapper</ref> Their destination was [[Howland Island]], a flat sliver of land 6,500&nbsp;ft (2,000&nbsp;m) long and 1,600&nbsp;ft (500&nbsp;m) wide, 10&nbsp;ft (3&nbsp;m) high and {{convert|2556|mi|nmi km}} away.<ref>{{cite gnis |id=1393033 he |name=Howland Island |access-date = February 24, 2009}}</ref> The expected flying time was about 20 hours; accounting for the two-hour time-zone difference between Lae and Howland, and the crossing of the [[International Date Line]], the aircraft was expected to arrive at Howland the morning of the next day, 2 July. The aircraft departed Lae with about {{convert|1100|USgal|l|abbr=off|sp=us}} of gasoline.{{sfn|Chater|1937}}

In preparation for the trip to Howland Island, the [[U.S. Coast Guard]] had sent the cutter {{USCGC|Itasca|1929}} to the island to offer communication and navigation support for the flight.<ref name="auto">{{Cite web|url=https://www.history.uscg.mil/Browse-by-Topic/Assets/Water/All/Article/2489592/itasca-1930|title=Itasca, 1930|website=United States Coast Guard}}</ref> The cutter was to communicate with Earhart's aircraft via radio, transmit a homing signal to help the aviators locate Howland Island, use radio direction-finding (RDF), and use the cutter's boilers to create a dark column of smoke that could be seen over the horizon.<ref name="auto"/> All of the navigation methods failed to guide Earhart to Howland Island.<ref name="auto"/>

Around <time datetime="1937-07-02T15:00+10:00">3&nbsp;pm Lae time</time>, Earhart reported her altitude as {{cvt|10000|feet}}, but that they would reduce altitude due to thick clouds. Around <time datetime="1937-07-02T17:00+10:00">5&nbsp;pm</time>, Earhart reported her altitude as {{cvt|7000|ft}} and speed as {{cvt|150|kn}}.{{sfn|Collopy|1937}} During Earhart's and Noonan's approach to Howland Island, ''Itasca'' received strong, clear voice transmissions from Earhart identifying as KHAQQ, but she was unable to hear voice transmissions from the ship.<ref name="auto"/>

The first calls received from Earhart were routine reports stating the weather was cloudy and overcast at <time datetime="1937-07-02T02:45-11:30" title="14:15Z">2:45&nbsp;am</time> and just before <time datetime="1937-07-02T05:00-11:30" title="16:30Z">5&nbsp;am on July 2</time>. These calls were broken up by static, but at this point, the aircraft was a long distance from Howland.{{sfn|Fleming|2011|p=2}} At <time datetime="1937-07-02T06:14-11:30" title="17:44Z">6:14&nbsp;am</time>, another call was received stating that the aircraft was within {{convert|200|miles|km}} and requesting that the ship use its direction finder to provide a bearing for the aircraft. Earhart began whistling into the microphone to provide a continuous signal for the ship's crew to use.{{sfn|Fleming|2011|p=3}} At this point, the radio operators on ''Itasca'' realized their RDF system could not tune into the aircraft's signal on 3105&nbsp;kHz; radioman Leo Bellarts later commented he "was sitting there sweating blood because I couldn't do a darn thing about it".<ref>{{Cite web|url=https://penguinrandomhouselibrary.com/book/?isbn=9780307980212|title=Amelia Lost|website=Penguin Random House Library Marketing}}</ref> A similar call asking for a bearing was received at <time datetime="1937-07-02T06:45-11:30" title="18:15Z">6:45&nbsp;am</time>, when Earhart estimated they were {{convert|100|miles|km}} away.{{sfn|Fleming|2011|p=4}}

An ''Itasca'' radio log at 7:30–7:40&nbsp;am states the aircraft had only a half hour of fuel remaining. A further radio log states they thought they were near ''Itasca'' but could not locate it and were flying at {{cvt|1000|feet}}.<ref>{{cite web |url=https://tighar.org/Projects/Earhart/Archives/Research/Bulletins/37_ItascaLogs/pos2page2.pdf |title=Radio Entries and Times |access-date = November 20, 2017 |url-status=live |archive-url = https://web.archive.org/web/20161021164910/http://tighar.org/Projects/Earhart/Archives/Research/Bulletins/37_ItascaLogs/pos2page2.pdf |archive-date = October 21, 2016 |df=mdy-all}}</ref> In her transmission at <time datetime="1937-07-02T07:58-11:30" title="19:28Z">7:58&nbsp;am</time>, Earhart said she could not hear ''Itasca'' and asked them to send voice signals so she could try to take a radio bearing. ''Itasca'' reported this signal as the loudest possible signal, indicating Earhart and Noonan were in the immediate area. The ship could not send voice at the frequency she asked for so they sent Morse code signals instead. Earhart acknowledged receiving these but said she was unable to determine their direction.<ref>Jacobson, Randall S., PhD. [http://tighar.org/Projects/Earhart/Research/ResearchPapers/Worldflight/finalflight3.html "The Final Flight. Part 3: At Howland Island."] {{webarchive|url=https://web.archive.org/web/20120716011358/http://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Worldflight/finalflight3.html |date=July 16, 2012 }} ''tighar.org'', 2009. Accessed: July 10, 2010.</ref>

[[File:USCGC Itasca.jpg|thumb|left|USCGC ''Itasca'' was at Howland Island to support the flight.]]

The last voice transmission received on Howland Island from Earhart indicated she and Noonan were flying along a line of position running north-to-south on 157–337 degrees, which Noonan would have calculated and drawn on a chart as passing through Howland.{{sfn|Safford|2003|p=145}} After all contact with Howland Island was lost, attempts to reach the flyers with voice and [[Morse code]] transmissions were made. Operators across the Pacific and in the United States may have heard signals from the Electra but these were weak or unintelligible.<ref>{{cite web |url= https://tighar.org/Projects/Earhart/Archives/Research/ResearchPapers/Brandenburg/signalcatalog2.html |title=Catalog and Analysis of Radio Signals During The Search for Amelia Earhart in July 1937 |last1=Brandenburg |first1=Bob |last2=Gillespie |first2=Ric |website=tighar.org |accessdate=November 18, 2024}}</ref>

A series of misunderstandings, errors or mechanical failures are likely to have occurred on the final approach to Howland Island. Noonan had earlier written about problems affecting the accuracy of RDF in navigation. Another cited cause of possible confusion was that ''Itasca'' and Earhart planned their communication schedule using time systems set a half-hour apart; Earhart was using [[Greenwich Civil Time]] (GCT) and ''Itasca'' was using a Naval time-zone designation system.<ref name="Hoversten">Hoversten 2007, pp. 22–23.</ref>

Sources have noted Earhart's apparent lack of familiarity with her direction-finding system, which had been fitted to the aircraft just prior to the flight. The system was equipped with a new receiver from [[Bendix Corporation]]. Earhart's only training on the system was a brief introduction by Joe Gurr at the Lockheed factory. A card displaying the antenna's band settings was mounted so it was not visible.{{sfn|Long|Long|1999|p=116}} The Electra expected ''Itasca'' to transmit signals the Electra could use as an RDF beacon to find the ship. In theory, the plane could listen for the signal while rotating its [[loop antenna]]; a sharp minimum indicates the direction of the RDF beacon. The Electra's RDF equipment had failed due to a blown fuse during an earlier leg flying to Darwin; the fuse was replaced.<ref>Abbott, 1937, {{cite web |url=https://tighar.org/Projects/Earhart/Archives/Documents/Letters/Abbott8_3_37.pdf |title=Enclosure No.2 to Despatch No.507 from the American Consulate General, Sydney, Australia, dated August 21, 1937, entitled "Round-the-world Flight of Miss Earhart" COPY. COMMONWEALTH OF AUSTRALIA. Northern Territory Administration, File No. 37/477. Darwin. 3rd August, 1937. |access-date = November 19, 2017 |url-status=live |archive-url = https://web.archive.org/web/20161019053024/http://tighar.org/Projects/Earhart/Archives/Documents/Letters/Abbott8_3_37.pdf |archive-date = October 19, 2016 |df=mdy-all}}</ref> Near Howland, Earhart could hear the transmission from ''Itasca'' on 7500&nbsp;kHz, but she was unable to determine a minimum so she could not determine a direction to the ship. Earhart was also unable to determine a minimum during an RDF test at Lae.{{sfn|Chater|1937}}

=== Disappearance ===
[[File:Amelia Earhart Disappears (1937).webm|thumb|[[Pathé News|Pathe newsreel]] detailing her 1937 disappearance]]

The U.S. government investigated the aircraft's disappearance and, in its report, concluded Earhart's plane ran out of fuel and crashed into the ocean.<ref>{{cite web | url=https://www.britannica.com/story/the-disappearance-of-amelia-earhart | title=The Disappearance of Amelia Earhart &#124; Britannica }}</ref> During the 1970s, retired [[United States Navy]] (USN) captain [[Laurance Safford]] began a lengthy analysis of the flight. His research included the intricate radio-transmission documentation. Safford concluded the flight had suffered from poor planning and worse execution.{{sfn|Strippel|1995|p=20}}

Many researchers believe Earhart and Noonan died during or shortly after the crash. In 1982, retired USN [[rear admiral]] Richard R. Black, who was in administrative charge of the Howland Island airstrip and was present in the radio room on ''Itasca'', said: "the Electra went into the sea about 10&nbsp;am, July 2, 1937, not far from Howland."{{sfn|Strippel|1995}} Earhart's stepson George Palmer Putnam Jr. has said he believes "the plane just ran out of gas".<ref>Kleinberg, Eliot.
[https://groups.google.com/forum/#!topic/alt.obituaries/8-SuGX6ATRg "Amelia Earhart's disappearance still haunts her stepson, 83."] {{webarchive|url=http://arquivo.pt/wayback/20110122130054/https://groups.google.com/forum/ |date=January 22, 2011 }} ''Palm Beach Post'', December 27, 2004. accessed: July 1, 2013.</ref> According to Earhart-biography author [[Susan Butler (American writer)|Susan Butler]], the aircraft went into the ocean out of sight of Howland Island and rests on the seafloor at a depth of {{convert|17000|ft|km|0|abbr=on}}.<ref>[https://www.pbs.org/opb/historydetectives/video/706_ameliaearhart.html "Amelia Earhart: Susan Butler interview."] {{webarchive|url=https://web.archive.org/web/20090731132917/http://www.pbs.org/opb/historydetectives/video/706_ameliaearhart.html |date=July 31, 2009 }} ''History Detectives'', Season 7 video. PBS. accessed: July 26, 2010.</ref> Tom D. Crouch, senior curator of the [[National Air and Space Museum]], has said the Electra is "18,000 ft. down" and compared its archaeological significance to that of ''[[RMS Titanic]]''.<ref name="Hoversten" />

British aviation historian Roy Nesbit interpreted evidence in contemporary accounts and Putnam's correspondence and concluded Earhart's Electra was not fully fueled at Lae.{{sfn|Strippel|1995|p=58}} William L. Polhemous, the navigator on [[Ann Pellegreno]]'s 1967 flight that followed Earhart and Noonan's original flight path, studied navigational tables for July 2, 1937, and thought Noonan may have miscalculated the "single line approach" to Howland.{{sfn|Strippel|1995|pp=58, 60}}

===Search efforts===

Beginning approximately one hour after Earhart's last recorded message, ''Itasca'' undertook an unsuccessful search north and west of Howland Island based on initial assumptions about transmissions from the aircraft. The U.S. Navy joined the search and over about three days sent available resources to the search area near Howland Island.{{sfn|Goldstein|Dillon|1997|p=251}} Official search efforts lasted until July 19, 1937.{{sfn|Safford|2003|pp=61–62, 67–68}} At $4&nbsp;million (equivalent to ${{Inflation|US|4|1937}}&nbsp;million in {{Inflation/year|US}}), the air-and-sea search by the U.S. Navy and [[United States Coast Guard|Coast Guard]] was the costliest and most intensive in U.S. history up to that time. Despite the unprecedented search, no physical evidence of Earhart, Noonan, or the Electra 10E was found.{{sfn|Goldstein|Dillon|1997|pp=245–254}}{{sfn|King|Jacobson|Burns|Spading|2001|pp=32–33}}

On the mornings of July 3 and July 6, 1937, an Oakland radio amateur was reported to have heard emergency transmissions, seemingly from Earhart.<ref name=radioupi>{{Cite web |date=July 6, 1937 |title=Amateur picks up message from Earhart |url=https://www.upi.com/Archives/1937/07/06/Amateur-picks-up-message-from-Earhart/3431821501408/ |access-date=2024-03-31 |work=[[United Press International]] |language=en}}</ref>{{efn|The reputed July 3 transmission was an SOS message in Earhart's voice, accompanied by her plane's call letters. The alleged July 6 message, heard on one of Earhart's bands, was in a faint voice and its gender was unidentifiable. It said, "Cannot hold out much longer". Putnam believed the messages to be authentic because they were within five minutes of the half hour, the expected interval of SOS messages.<ref name=radioupi/>}} In the days after their last confirmed transmissions, further transmissions purporting to be from Earhart were reported, many of which were determined to be hoaxes. The captain of {{USS|Colorado|BB-45|6}} later said: "There was no doubt many stations calling the Earhart plane on the plane's frequency, some by voice and others by signals. All of these added to the confusion and doubtfulness of the authenticity of the reports."{{sfn|Gillespie|2006|p=146}}

Immediately after the end of the official search, Putnam financed a private search by local authorities of nearby Pacific islands and waters. In late July 1937, Putnam chartered two small boats and, while he remained in the United States, directed a search of other islands.{{sfn|Goldstein|Dillon|1997|p=257}} Putnam acted to become the trustee of Earhart's estate so he could pay for the searches and related bills. In probate court in Los Angeles, Putnam asked to have the "[[declared death in absentia|declared death ''in absentia'']]" seven-year waiting period waived so he could manage Earhart's finances. As a result, Earhart was declared legally dead on January 5, 1939.{{sfn|Van Pelt|2005|p=205}}

In 2003 and 2006, [[David Jourdan]], through his company Nauticos, extensively searched a {{convert|1200|sqmi|km2|adj=on}} area north and west of Howland Island with deep-sea sonar devices. The searches cost $4.5&nbsp;million but did not find any wreckage. The search locations were derived from the line of position (157–337) broadcast by Earhart on July 2, 1937.<ref name="Hoversten" />

In 2024, Deep Sea Vision, a Charleston, South Carolina, company that operates [[unmanned underwater vehicle]]s, found via sonar what it said could be the remains of Earhart's airplane on the ocean floor.<ref>{{Cite news |last=Smith |first=Stephen |date=2024-01-29 |title=Amelia Earhart's long-lost plane possibly detected by sonar 16,000 feet underwater, exploration team claims |url=https://www.cbsnews.com/news/amelia-earhart-plane-possibly-detected-sonar-underwater-deep-sea-vision/ |work=CBS News |language=en-US}}</ref><ref>{{cite news |last=Kim |first=Juliana |date=January 29, 2024 |title=Amelia Earhart's long-lost plane possibly spotted in the Pacific by exploration team |url=https://www.npr.org/2024/01/29/1227574179/amelia-earharts-lost-plane-howland-island |access-date=January 29, 2024 |work=[[NPR]]}}</ref> The object, which was {{cvt|16000|ft|km}} deep and about {{convert|100|mi|km|abbr=on}} from Howland Island, turned out to be a rock formation.<ref>{{Citation | vauthors=((Deep Sea Vision)) | year=2024 | title=Deep Sea Vision - Services | url= https://www.deepseavision.com/service-details | access-date=11 August 2024}}</ref><ref>{{cite news|url=https://www.wsj.com/science/environment/an-adventurer-thought-he-found-amelia-earharts-plane-now-he-says-it-was-rock-466309d2?st=3GWrWb&reflink=article_copyURL_share|title=An Adventurer Thought He Found Amelia Earhart's Plane. Now He Says It Was a Rock|first=Nidhi|last=Subbaraman|newspaper=Wall Street Journal|date=November 5, 2024|accessdate=November 9, 2024}}</ref><ref>{{cite news|url=https://www.latimes.com/california/story/2024-11-08/he-thought-hed-found-amelia-earharts-plane-it-was-a-pile-of-rocks|title=He thought he'd found Amelia Earhart's plane. It was a pile of rocks|first=Thomas|last=Curwen|work=Los Angeles Times|date=8 November 2024|accessdate=9 November 2024}}</ref>