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    Re: Finally, a reasonable explanation for Earhart's failure to find Howland
    From: Geoffrey Kolbe
    Date: 2013 Feb 26, 07:49 +0000
    H.A.C.van Asten wrote:

    Mr.Lapook´s explanation arrives close to the one published 2008-2011 in European Journal of Navigation in a three articles series , pdf available at davidkbowman.com , select "Technical Articles". The addendum to article no.3 (on the on board NR 16020 fuel management)refers to a via Choiseul Island detour between Lae and Nukumanu Island , originally proposed by mr.Lapook , as in the addendum mentioned .



     It would seem that Mr H.A.C.van Asten is being shy and the cited articles were by Mr H.A.C.van Asten himself. The cited website front page does not appear to list "Technical Articles", but a little inspiration found the
    articles at http://www.davidkbowman.com/articles

    The April 2011 article "Frederick Noonan Precomputed a Running Sunset Fix for Amelia Earhart's Flight from New Guinea to Howland. July 2. 1937" is found here:

    http://www.davidbowman.com/wagner_noonan.pdf

    The conclusion of the article would appear to be encapsulated in this sentence.

    "During the to Howland flight of the Earhart-Noonan crew, an observation of sunset with the bubble sextant, [ A/c @ 7000 ft, no optical horizon ] at 0719:30 GMT followed by the 0720 GMT radio announcement placed the aircraft close to if not spot on the coordinates pair 159°07´-E; 04°33´.5-S, 27 miles southwestwards of the Nukumanu Islands, which is unconditional proof that the originally for the March, 1937 Howland to Lae, New Guinea, precomputed great circle trail running 13 stat.miles northwards, prerequisited in many if not all current publications on the subject, was not flown during the in reverse sense voyage of July 2."

    I also learn that: "HF spectrum radio signals of the 2,000  4,000 kcs frequency suffer absorption by sunlight in the lower troposphere and up to the 60 miles level of the stratosphere." which is certainly something I did not know before and for which I thank Mr H.A.C.van Asten. It is also nice to see "cycles" still being used as a unit of frequency some forty years after the new-fangled "Hertz" came into fashion.

    Article number three can be found here http://www.davidkbowman.com/EJN-New.pdf and indeed goes into exhaustive detail on the fuel management of flight NR 16020. There was, however, no mention of "Choiseul Island"

    Geoffrey Kolbe

       
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