Map of Howland Island provided to Earhart by navigational consultant Clarence S. Williams.

Deep Sea Vision say their search area was based on The Date Line Theory which holds that, in navigating to Howland Island, Fred Noonan failed to account for crossing the International Date Line, resulting in him thinking the island was fully 60 nautical miles west of where it really was. Noonan was not the flawless navigator the Earhart legend has made him out to be, but crossing the Date Line was something he had done on his many trans-Pacific flights as Pan American’s senior navigator. To assume he made such a basic error on July 2nd is quite a stretch, and there is no evidence that he did, but it helps explain why DSV was excited about a vaguely airplane-shaped sonar target less than a hundred miles west of Howland.

It also raises the question of where Noonan actually did think his destination was. The charts navigational consultant Clarence S. Williams prepared in 1936 for Earhart’s first world flight attempt showed Howland at its most-recently published position – 0°49' N, 176°43'  W. It’s not very good – that location is six nautical miles west of the island – but the true location was classified “confidential” by the U.S. Hydrographic Office until its maps could be updated, which didn’t happen until 1938 or '39.  The person who reported the revised locations to the Hydrographic Office was William Miller, an employee of the Bureau of Air Commerce who, in early 1937, had worked closely with navigator Harry Manning in planning the Pacific legs of Earhart’s world flight. That Miller would not clue up Manning to the island’s corrected position – 0° 48' 06'' N, 176° 38' 12" – is inconceivable, and if Manning knew, Noonan knew. The new coordinates, in fact, still weren’t quite right. If Noonan had those numbers, he thought Howland was one nautical mile west of where it is, but whether one mile or six miles off, it shouldn’t have prevented him from finding Howland if he was anywhere near on-course. 

That the aircraft ultimately landed at Gardner Island has been established beyond a reasonable doubt. Precisely how it got there is unknown and unknowable, but the known data suggest a plausible sequence.

During the overcast night, Noonan was unable to get star sightings to check their position and stronger than forecast winds from the northeast caused the flight to drift off course. As a result, they hit the 157-337 Line of Position about 150 nautical miles southwest of Howland, but all Noonan knew was that the island had not appeared as expected (“We must be on you but cannot see you...”). He knew he was on a line that passed through their destination, but he had no way of knowing whether he was north or south of Howland. The only thing he could do was search up and down the Line of Position (“We are on the line 157-337 … running on line north and south”). They ran north for a while but gave up too soon. They reversed course and began searching south, which eventually brought them to Gardner Island.

The data and rationale behind this scenario are covered in detail in One More Good Flight – The Amelia Earhart Tragedy, to be released in September. The book can be pre-ordered from the Naval Institute Press and Amazon. Signed copies can be pre-ordered from TIGHAR HERE.

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