If mr.Noonan saw sunrise from 1,000 ft altitude @ 1752:38 GMT and counted off 2m15s for actual sunrise @ 1754:53 , there is a good chance that the positon line they arrived on runs 10 miles west of Howland´s then charted position , and A/c has supposedly alighted when on that line . Several manuals of the era contain prescription how to establish longitude @ sunset and sunrise when at sea .
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We have thoroughly discussed Mr. van Asten's theories on the
Navigating the LOP with the offset method topic, see:
https://tighar.org/smf/index.php/topic,169.120.htmlstarting with reply 120
and subsequent posts, especially reply 203 pointing out his 300 NM error in his computation of this "10 mile" error line and his admission of this error in reply 204.
https://tighar.org/smf/index.php/topic,169.203.htmlMr. van Asten has never produced any cite to any contemporary
flight navigation text book or manual supporting his method and his theories about determining longitude at sunrise in spite of my many requests for such support. To be fair, he did point me to a
1986 marine navigation book entitled
Emergency Navigation (which I have on my bookshelf) which describes hundreds of emergency navigation methods and that does mention his method but also contains the warning that this method only produces a longitude with, at best, an uncertainty of plus and minus twenty minutes of longitude, a band 40 NM wide, and also possibly much greater errors. Due to additional factors involved in flight navigation, any attempt to use the method in
Emergency Navigation in flight would produce a much larger band of uncertainty. This method would not produce a longitude with the precision necessary to find Howland even if used by a navigator on a ship. After all, the method is mentioned in a book entitled
Emergency Navigation meaning that it may be useful in an emergency when it is better than nothing. I'm pretty certain that Noonan never read this book.
Read Mr. van Asten's submissions at your own risk.
gl
gl