The Disappearance of Amelia Earhart (1937): What Happened Near Howland Island.

What happened to Earhart and Noonan, in a paragraph.

Amelia Mary Earhart, age 39, the first woman to fly the Atlantic solo and at that point the most famous female aviator in the world, departed Oakland, California on May 21, 1937 in her Lockheed Electra 10E NR16020 on a planned 29,000-mile round-the-world flight along the equator. Her navigator was Frederick J. Noonan, age 44, a former Pan American Airways flight officer with extensive Pacific celestial-navigation experience. The flight proceeded east from Oakland via Miami, Puerto Rico, South America, Africa, India, Southeast Asia, and Australia, reaching Lae, New Guinea on June 29, 1937. From Lae the next planned leg was 2,556 nautical miles east-northeast across the central Pacific to Howland Island, a half-mile-wide, twenty-foot-high uninhabited atoll on which a runway had been graded specifically to support the flight. Howland's tiny size and the celestial-navigation precision required to find it from 2,556 miles away made this the most demanding navigational leg of the entire flight. To support the rendezvous, the U.S. Coast Guard cutter Itasca was anchored off Howland on radio watch, ready to provide direction-finding bearings and to mark the island with a smoke plume. The Electra departed Lae at 1000 local time (0000 GMT) on July 2, 1937. Earhart's radio transmissions to the Itasca began approximately fourteen hours into the flight as the aircraft approached the Pacific dateline; the transmissions, of which the Itasca received approximately a dozen and recorded contemporaneously in the ship's radio log, are the only direct record of the flight after departure. The last clearly received voice transmission was at 0843 local Howland time on July 2: "We are on the line 157 337. We will repeat this message. We will repeat this on 6210 kilocycles. Wait." The Electra was never heard from again. The U.S. Navy and Coast Guard mounted the largest sea-and-air search to that date, covering approximately 250,000 square miles of central Pacific over sixteen days, finding nothing. Earhart and Noonan were declared lost at sea on July 19, 1937. The principal hypotheses surviving in serious scholarship are (1) "crashed and sank" — the Electra ran out of fuel near Howland and went down within the search-region's central focus; (2) "Nikumaroro / Gardner Island castaway" — the Electra continued southeast on the line-of-position to Nikumaroro (Gardner Island, in the British Phoenix group), landed on the reef, and Earhart and Noonan died there as castaways; and (3) the "Japanese capture" account — the aircraft landed or was forced down in the Japanese Mandated Islands (Marshall Islands, Mili Atoll, or Saipan), where Earhart and Noonan were taken into custody and later died. None of these hypotheses has been resolved by recovered physical remains. The 2024 Deep Sea Vision sonar survey, which produced an anomaly initially announced as a possible Electra, was on follow-up investigation determined to be a natural underwater feature. The case is open.

The documented record.

The flight

The round-the-world flight was Earhart's second attempt. Verified The first attempt, west-east from Oakland to Honolulu in March 1937, ended on takeoff from Luke Field, Hawaii on March 20, 1937 when the Electra's main landing gear collapsed in a ground loop, damaging the aircraft. The Electra was shipped back to California, repaired by Lockheed, and the route reversed to east-west to take advantage of seasonal weather patterns; the second attempt departed Miami on June 1, 1937 [1].

By the time the Electra reached Lae, New Guinea on June 29, the round-the-world flight had covered approximately 22,000 miles. Verified Earhart had cabled the New York Herald-Tribune from Lae that she was tired but determined and that "the whole width of the world has passed behind us." She and Noonan were observed by the Lae station manager Eric Chater and by photographer F.C. Jacobs preparing the aircraft and themselves for departure. The Electra's fuel load for the Howland leg was 1,100 U.S. gallons, providing approximately 20–21 hours of flight at typical cruise; the Lae-to-Howland leg was estimated by Noonan at 18 hours. Photographs taken by Jacobs in the last hours at Lae show the aircraft with a clearly damaged or modified radio antenna underneath the fuselage; whether the belly antenna was present or had been lost in the Hawaii ground-loop incident has been the subject of subsequent debate, with consequences for the radio reception that followed [1][2].

The Itasca radio log

The single most important documentary record of the flight after Lae is the radio operations log of the USCGC Itasca, the Coast Guard cutter anchored off Howland. Verified The Itasca, under the command of Commander Warner K. Thompson, had been positioned at Howland specifically to support the rendezvous, with three radio operators (Leo Bellarts, Frank Cipriani, and Thomas O'Hare) on continuous watch on the agreed frequencies (3105 kHz nighttime, 6210 kHz daytime). The Itasca's radio log records the following voice transmissions from the Electra, all in Earhart's voice, between 0245 and 0843 Howland local time (the Itasca's clock was 1.5 hours behind Earhart's chosen local time):

• 0245 "Cloudy weather, cloudy" (faint).
• 0345 "ITASCA from EARHART... overcast... will listen on hour and half hour on 3105" (S-3 strength).
• 0453 "Partly cloudy" (faint).
• 0614 "Want bearing on 3105... about 200 miles out... whistling now" (S-4 strength).
• 0645 "Please take bearing on us and report in half hour, I will make noise in microphone — about 100 miles out" (S-4).
• 0742 "KHAQQ calling Itasca. We must be on you but cannot see you. But gas is running low. Have been unable to reach you by radio. We are flying at 1,000 feet." (S-5, fully readable).
• 0758 "KHAQQ calling Itasca. We are circling but cannot hear you. Go ahead on 7500 either now or on the scheduled time on half hour."
• 0800 Itasca transmits its identification signal on 7500 kHz; Earhart replies "Itasca, we are receiving your signals but unable to get a minimum. Please take a bearing on us and answer 3105 with voice."
• 0843 "We are on the line 157 337. We will repeat this message. We will repeat this on 6210 kilocycles. Wait." (the final transmission).

After 0843 the Itasca received no further confirmed transmissions from the Electra. Verified The radio operators continued listening for several hours and broadcasting blind in case Earhart could receive. Approximately three hours after the last transmission, with the aircraft's estimated fuel exhausted, the Itasca began standard search-and-rescue procedure [3][4].

The "line 157 337" referenced in the last transmission is a sun-line of position — a celestial line of position computed from a sun shot, oriented at a heading of 157°/337° magnetic. Howland Island lies on such a sun-line at that morning's hour. The line was Earhart and Noonan's last-resort navigation: when they could not locate Howland by ordinary dead reckoning, they fell back on a sun-line that, by definition, passed through Howland; they would fly along that line in both directions, expecting to either find Howland or the alternate islands south-southeast of Howland (the Phoenix group, of which Nikumaroro is one) [3].

The 1937 search

The U.S. Navy and Coast Guard mounted what was, at the time, the largest sea-and-air search in history. Verified The aircraft carrier USS Lexington, the battleship USS Colorado, the seaplane tender USS Swan, and several other vessels were diverted to the region. The Colorado's catapult-launched seaplanes overflew the Phoenix Islands on July 9, 1937, photographing Nikumaroro (then Gardner Island) and the other islands; the pilots' reports include observations of "signs of recent habitation" on Gardner Island, though the island had been uninhabited since the 1892 abandonment of a small British settlement. The Lexington's aircraft searched approximately 150,000 square miles around Howland. Total search area is conventionally given as approximately 250,000 square miles. No wreckage, no debris, no positive identification was recovered. The search was concluded on July 19, 1937 [3][5].

The post-loss radio signals

In the days and weeks following the disappearance, hundreds of radio operators across the Pacific and North America reported having received fragmentary transmissions interpreted as possible Earhart distress calls. Verified Many of these were quickly judged hoaxes; some were judged plausible by the contemporaneous U.S. Navy radio-direction-finding network. The most consequential were a series of bearings taken by the Pan American direction-finding stations at Mokapu (Hawaii), Wake Island, and Midway between July 3 and July 7, 1937, which approximately intersected in the region of the Phoenix Islands — specifically near Nikumaroro/Gardner. The Pan American bearings, declassified in the post-war period, have been one of the principal inputs to the Nikumaroro hypothesis [6][7].

The 1940 Nikumaroro skeleton

In April 1940, a British Western Pacific High Commission party led by Gerald Gallagher discovered a partial human skeleton, a sextant box, a woman's shoe, and other artifacts on the southeast side of Gardner Island (Nikumaroro). Verified The bones were transmitted to Suva, Fiji, where they were examined by Dr. David W. Hoodless in 1941. Hoodless concluded from his cranial and femoral measurements that the bones were those of a stocky middle-aged male of European ancestry, not those of a female. The bones were subsequently lost; only Hoodless's measurements (femur, tibia, humerus, radius, partial skull) survive.

In 1998, anthropologist Karen Burns and TIGHAR (The International Group for Historic Aircraft Recovery) reanalyzed the Hoodless measurements using the Fordisc software for ancestry and sex estimation, and concluded that the bones were more consistent with a tall woman of European descent than with the male identification Hoodless had reached. Disputed In 2018, forensic anthropologist Richard L. Jantz of the University of Tennessee published a more sophisticated reanalysis in Forensic Anthropology, comparing the Hoodless measurements to the known dimensions of Earhart's clothing and to Earhart-era photographic measurements of her body proportions. Jantz concluded that the Hoodless bones were more consistent with Earhart's measurements than with 99% of a reference sample. The Jantz analysis has been received favorably by some forensic anthropologists and skeptically by others; the central problem is that the bones themselves are lost and the analysis depends on the Hoodless 1941 measurements, which under modern standards are sparse [7][8].

TIGHAR and Nikumaroro

The International Group for Historic Aircraft Recovery (TIGHAR), founded by Richard Gillespie in 1985, has conducted twelve expeditions to Nikumaroro between 1989 and 2017 in pursuit of the castaway hypothesis. Verified TIGHAR's recovered material includes: fragments of plexiglas consistent with the Electra's cockpit windows; a zipper pull consistent with 1930s American manufacture; a fragment of a woman's compact mirror; a freckle-cream jar lid (Earhart was known to be self-conscious about her freckles and to use a specific brand of cream); fragments of a 1937-vintage shoe heel; and a substantial number of fish, bird, and turtle bones suggesting a sustained period of subsistence cooking at a site on the southeast shore (the "Seven Site"). TIGHAR has also identified an aluminum panel (Artifact 2-2-V-1) that they argued was a patch installed on the Electra at the Miami stopover and which they claimed matched a panel visible in a Miami-departure photograph; subsequent analysis by Lockheed Martin and independent researchers has contested this identification. None of the recovered material has been confirmed beyond reasonable doubt as belonging to Earhart or Noonan [7][9].

The Bevington photo

In 2010 TIGHAR drew attention to a photograph taken in October 1937 by Eric Bevington, a British colonial cadet visiting Gardner Island, that showed a small protrusion above the surface of the lagoon shoreline. Claimed TIGHAR commissioned U.S. State Department forensic image analysis (Jeff Glickman) who concluded in 2012 that the protrusion was consistent in dimensions with the landing-gear strut of a Lockheed Electra 10E. The Bevington-photo identification has been one of TIGHAR's most-cited pieces of evidence; the National Geographic Society endorsed an expedition based on it in 2012. The expedition did not locate any wreckage at the indicated site. Critics have argued the protrusion is most likely a coral outcrop. The interpretation is disputed [10].

The 2024 Deep Sea Vision sonar anomaly

In January 2024, Deep Sea Vision, a private South Carolina exploration company under Tony Romeo, announced that its sonar survey of approximately 5,200 square miles of seafloor near Howland Island had identified an anomaly approximately 16,500 feet deep that matched the dimensions and apparent profile of the Lockheed Electra 10E. Claimed The announcement received international coverage. A follow-up Deep Sea Vision expedition in November–December 2024, using a higher-resolution autonomous underwater vehicle to image the target directly, determined that the anomaly was a natural geological formation, not an aircraft. Deep Sea Vision issued a confirmatory statement in early 2025 acknowledging this and announcing continued searching elsewhere [11].

The proposed explanations.

Crashed and sank (the U.S. Navy / mainstream view)

The explanation officially adopted by the U.S. Navy in its 1937 search summary, and the one preferred in most aviation-historical scholarship through the present, is that the Electra ran out of fuel near Howland and ditched in the central Pacific within the search-region's central focus. Claimed Under this account, the "line 157 337" transmission represents Earhart and Noonan executing their pre-planned contingency: when they could not find Howland visually or by radio bearing, they ran the sun-line in both directions; they exhausted fuel before locating either Howland or an alternative landfall, and ditched. The aircraft sank to the deep Pacific abyssal plain, where it has not been located by any of several subsequent search expeditions. The case for this hypothesis is the documentary record of the radio transmissions (consistent with an aircraft near Howland), the negative result of the 1937 surface search (consistent with the wreck being already on the bottom), and the absence of confirmed survivor evidence anywhere. Counterarguments include the documented post-loss radio signals (which would have required an above-water radio antenna and engine power, neither possible from a submerged or floating wreck) and the various Nikumaroro/Phoenix Islands material that has been recovered [3][12]. The 2024 Deep Sea Vision survey, despite the false-positive anomaly, is consistent with this hypothesis: the search region is the right region; the wreck simply has not been located within it.

The Nikumaroro / Gardner Island castaway hypothesis

The Nikumaroro hypothesis, developed in detail by TIGHAR over four decades, proposes that Earhart and Noonan, finding the sun-line and unable to locate Howland, flew the line southeast and located Nikumaroro (then Gardner Island), 350 nautical miles south-southeast of Howland in the Phoenix group. Claimed The Electra landed on the dry reef flat at low tide, was used as a radio platform for several days (the post-loss radio signals, under this account, are partly genuine), and was subsequently washed off the reef and destroyed by surf. Earhart and Noonan survived for some unknown period as castaways on the island, dying of exposure, dehydration, or illness; the 1940 Gallagher bones represent at least one of them. The hypothesis accommodates the post-loss radio bearings (the Pan American bearings pointed toward the Phoenix group), the 1940 bones (whose modern reanalysis is consistent with Earhart), the Seven Site cooking and clothing material, the 1937 USS Colorado pilots' "signs of recent habitation" observation, and the various recovered artifacts. Counterarguments include the absence of a confirmed aircraft on or near Nikumaroro despite many sonar and shore searches, the disputed nature of several key identifications (Bevington photo, Artifact 2-2-V-1), and the contested forensic value of the lost 1940 bones [7][8][9][13].

The Japanese capture account

The third hypothesis, which has been persistent in popular accounts but has never been supported by Japanese or American government records, is that the Electra reached the Japanese Mandated Islands (probably the Marshalls, with Mili Atoll most often named) where Earhart and Noonan were taken into Japanese custody, transferred to Saipan, and died there in captivity. Disputed The account derives principally from postwar testimony of Saipan and Marshallese residents recorded by U.S. servicemen during the 1944 American liberation of those islands, in which several witnesses claimed to have seen a white woman aviator in Japanese custody during the late 1930s. A 2017 History Channel documentary published a Japanese-archive photograph from Jaluit Atoll that purported to show Earhart and Noonan in custody on a Marshallese dock; the photograph was within hours of publication identified by a Japanese researcher as having been published in a 1935 Japanese travel book, predating the Earhart flight by two years. The hypothesis is unsupported by any contemporary Japanese government record (Japanese archives have been examined in detail) and is contradicted by the navigational record (the Marshalls are approximately 800 nautical miles north-northwest of the Electra's known position track and would have required a major navigational reversal) [14].

The Earhart family's view, as expressed across the decades by Earhart's sister Muriel Morrissey and her great-niece Amy Kleppner, has shifted between hypotheses. As of 2026, family statements have expressed support for the Nikumaroro castaway hypothesis as the most evidence-consistent of the three [15].

The unanswered questions.

The aircraft

Despite multiple expeditions to the central Pacific deep ocean using sonar, multibeam bathymetry, and autonomous underwater vehicles — including Nauticos in 2002 and 2006, Waitt Institute in 2009, TIGHAR's underwater surveys around Nikumaroro, and Deep Sea Vision in 2023–2024 — no confirmed Lockheed Electra wreckage has been identified in the search region. Unverified The unsearched portion of the central Pacific deep ocean within plausible Electra range is large, and the conventional view is that the aircraft is most likely on the bottom there, simply not yet found.

The 1940 bones

The bones found by Gallagher on Nikumaroro in April 1940 are lost. Unverified They were sent to Fiji for examination by Hoodless, who measured them and stored them in his department's collection. Subsequent inquiry by TIGHAR and others has been unable to relocate them; they may have been discarded, destroyed in WWII Fiji, or simply mislabeled and absorbed into the general collection. The Jantz 2018 analysis is based on the Hoodless 1941 measurements alone; modern DNA analysis is impossible without the bones themselves. Whether the Gallagher remains were Earhart, Noonan, an earlier shipwreck victim, or someone else cannot be definitively resolved.

The post-loss radio signals

Approximately 120 reported post-loss radio signals were assessed by the 1937 U.S. Navy investigators and by later TIGHAR analysis (which conducted the most thorough catalog in the late 1990s). Disputed A subset — roughly fifty signals received between July 3 and July 7, 1937 — have characteristics (timing, content, propagation consistent with shortwave from the Phoenix Islands region) judged credible by some analysts and rejected by others. The signals are the strongest documentary support for the Nikumaroro hypothesis if they are genuine; they are an aberration in the search record if they are not.

The navigation question

Why Noonan, an experienced Pacific celestial navigator, could not locate Howland Island with greater precision is one of the case's persistent technical questions. Disputed Several factors have been proposed: an undetected drift error in the dead-reckoning track from Lae; the loss of the trailing antenna or belly antenna that would have limited radio direction-finding capability; cloud cover preventing celestial fixes; and Earhart's reported aversion to operating the radio at altitude and frequencies optimal for the Itasca's direction-finding equipment. The cumulative effect of these factors, none individually catastrophic, may have placed the Electra fifty miles or more north or south of Howland when it should have been overhead [16].

The fuel question

The Electra carried 1,100 U.S. gallons of fuel from Lae, providing 20–21 hours of endurance at typical cruise. Disputed Earhart's last transmission at 0843 was approximately 20 hours into the flight, near the end of the fuel envelope. Whether the aircraft had sufficient fuel to fly the additional 350 nautical miles southeast to Nikumaroro after the 0843 transmission has been argued both ways. The most-cited reconstructions (Long, Goerner, TIGHAR) place the remaining fuel at the moment of the last transmission between 30 minutes and four hours, depending on assumed cruise economy. The lower end of that range is inconsistent with reaching Nikumaroro; the higher end is consistent.

Primary material.

• The USCGC Itasca Radio Operations Log, July 2, 1937. U.S. National Archives, RG 26 (Coast Guard).
• U.S. Navy Bureau of Aeronautics records of the 1937 search, including the Colorado and Lexington aircraft observations and the search-area maps. U.S. National Archives.
• The British Western Pacific High Commission archives (Fiji and London), containing Gerald Gallagher's April 1940 correspondence on the Gardner Island bones discovery, the Hoodless measurement report, and the subsequent investigation files.
• The Pan American Airways Pacific Direction-Finding station records (Mokapu, Wake, Midway), held in part at the University of Miami's Pan American Airways collection.
• TIGHAR archive (tighar.org) holds the comprehensive Nikumaroro-hypothesis materials, including the twelve expedition reports, the Seven Site catalog, the Bevington photo analysis, and the Jantz 2018 analysis.
• Purdue University Special Collections holds the Amelia Earhart Papers, including pre-flight correspondence and Earhart's own writings.
• The Smithsonian National Air and Space Museum holds Earhart-related artifacts and is the principal U.S. institutional repository for the aviation-historical record.

Key individual documents include: the Itasca radio log (July 2, 1937); the Hoodless skeletal measurement report (1941); the Pan American direction-finding bearings (July 3–7, 1937); the Jantz 2018 analysis paper; and the Deep Sea Vision 2024 sonar imagery (anomaly subsequently determined to be a natural feature).

The sequence.

1. May 21, 1937 Second world-flight attempt departs Oakland, California, east-bound.
2. June 29, 1937 Electra arrives Lae, New Guinea after 22,000 miles.
3. July 2, 1937, 1000 local Lae time Electra departs Lae for Howland Island, 2,556 nautical miles east-northeast.
4. July 2, 1937, 0742 Howland time "We must be on you but cannot see you. But gas is running low."
5. July 2, 1937, 0843 Howland time Final transmission: "We are on the line 157 337..."
6. July 2–19, 1937 Navy and Coast Guard search of approximately 250,000 square miles, USS Lexington, USS Colorado, USS Swan, and other vessels. No wreckage.
7. July 3–7, 1937 Pan American direction-finding stations record radio bearings that approximately intersect in the Phoenix Islands region.
8. July 9, 1937 USS Colorado catapult-launched aircraft overfly the Phoenix Islands including Gardner Island (Nikumaroro); pilots report "signs of recent habitation."
9. July 19, 1937 Search concluded. Earhart and Noonan declared lost at sea.
10. January 5, 1939 Earhart and Noonan declared legally dead in absentia by Los Angeles County Superior Court.
11. April 1940 Gerald Gallagher discovers partial skeleton, sextant box, woman's shoe on southeast Gardner Island.
12. 1941 Hoodless examines bones in Fiji, concludes "male of European ancestry." Bones subsequently lost.
13. 1944 American liberation of Saipan; postwar Saipan and Marshallese resident testimony enters the Japanese-capture hypothesis literature.
14. 1985 TIGHAR founded by Richard Gillespie.
15. 1989 First TIGHAR expedition to Nikumaroro.
16. 1998 Burns/TIGHAR reanalysis of the Hoodless measurements using Fordisc software.
17. 2010—2012 TIGHAR identifies Bevington 1937 photograph protrusion as possible Electra landing-gear strut.
18. 2017 History Channel "Earhart in Japanese custody" photograph published and within hours debunked as a 1935 image.
19. 2018 Jantz reanalysis of Hoodless measurements: bones "more consistent with Earhart than 99% of reference sample."
20. January 2024 Deep Sea Vision announces sonar anomaly near Howland matching Electra profile.
21. November–December 2024 Follow-up Deep Sea Vision expedition determines the anomaly to be a natural underwater feature.

Cases on this archive that connect.

The Mary Celeste (File 032) — another open-ocean disappearance in which the physical "scene" (in the Earhart case, the search region) has been searched in detail without producing remains or wreckage capable of resolution.

The Lost Colony of Roanoke (File 015) — a sustained-disappearance case in which decades of investigation have produced material that is "consistent with" multiple hypotheses without confirming any.

Planned: Glenn Miller (1944 disappearance over the English Channel); the Star Tiger and Star Ariel (1948 and 1949 Avro Tudor airliner disappearances in the Bermuda Triangle); the Flight 19 disappearance (1945).

Full bibliography.

1. Earhart, Amelia, Last Flight, edited by George Palmer Putnam, Harcourt, Brace, 1937. Pre-departure narrative pieces and dispatches.
2. Chater, Eric H., Lae station manager, statement on Electra's departure from Lae, July 1937. New Guinea Mining Bulletin and subsequent reprintings.
3. USCGC Itasca Radio Operations Log, July 2, 1937. U.S. National Archives, RG 26.
4. U.S. Navy Bureau of Aeronautics, Final Report on the Search for Amelia Earhart, July 1937. U.S. National Archives.
5. U.S. Navy Department, ONI report on the Phoenix Islands search overflights, July 9, 1937. National Archives, RG 38.
6. Pan American Airways Pacific Division, Direction-Finding bearing records, July 3–7, 1937. University of Miami Special Collections.
7. The International Group for Historic Aircraft Recovery (TIGHAR), Earhart Project field reports and analyses, 1989–2017. tighar.org.
8. Jantz, Richard L., "Amelia Earhart and the Nikumaroro Bones: A 1941 Analysis versus Modern Quantitative Techniques," Forensic Anthropology 1(2):83–98, 2018.
9. Burns, Karen R. and Hoshower, Lisa M., reanalysis of the Hoodless measurements using Fordisc, 1998. TIGHAR collection.
10. Glickman, Jeff, U.S. State Department forensic image analysis of the Bevington photograph, 2012. TIGHAR-commissioned.
11. Deep Sea Vision, sonar survey report (January 2024) and AUV imaging follow-up (November–December 2024). Deep Sea Vision press releases and Department of Hawaiian Marine archaeology cooperation files.
12. Long, Elgen and Long, Marie, Amelia Earhart: The Mystery Solved, Simon & Schuster, 1999. The principal "crashed and sank" synthesis.
13. Gillespie, Ric, Finding Amelia: The True Story of the Earhart Disappearance, Naval Institute Press, 2006. The principal Nikumaroro synthesis.
14. Goerner, Fred, The Search for Amelia Earhart, Doubleday, 1966. The principal early Japanese-capture synthesis; subsequently retracted in important respects by Goerner.
15. Morrissey, Muriel Earhart, and Osborne, Carol L., Amelia, My Courageous Sister, Osborne Publishing, 1987.
16. Safford, Laurance F. and Payne, Cameron A., Earhart's Flight Into Yesterday, McFarland, 2003. Detailed analysis of the Lae-to-Howland navigation.