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Re: Earhart's Plane - Search For?
From: Gary LaPook
Date: 2011 Apr 25, 18:57 -0700
From: Gary LaPook
Date: 2011 Apr 25, 18:57 -0700
My further, further comments on the Waitt report: ----------------------------------------------------------------------------------- Continuing my review of the Waitt report: Page 48-49 The report states that no handy calculators were available to make the conversions between indicated airspeed, true airspeed and ground speed until the invention of the circular slide rule type flight computer E-6B in World War Two. The report is only off by one World War. These devices were developed as early as 1910 and found wide use in WW I. The Dalton MK VII was perfected in1932 and the Jensen in 1933. These were as easy to operated and performed the required calculations. With slight modification the Dalton became standardized as the E-6B in WWII. So AE most likely could have made these calculations by herself in the cockpit. Noonan wrote a letter to Weems in which he stated he used the Dalton computer, see: https://sites.google.com/site/fredienoonan/resources/weems/weems-424-425.JPG?attredirects=0 https://sites.google.com/site/fredienoonan/resources/weems/weems-422-423.JPG?attredirects=0 Page 49 Report analyzes AE's notes. While crossing the Atlantic, she had written: "6:50 Just crossing equator, 6000 feet, Sun brilliant..." Waitt's explanation: o“6:50”is then the Natal local time of this logbook entry, and the local time of the equator crossing. o With this entry is “sun brilliant” which may refer to sunrise, which in Natal on the morning of June 7, 1937 was at 0636 local time." NO!!!!!!! At this point they are over 500 NM from Natal so what could this have to do with sunrise at Natal? "Sun brilliant" obviously is referring to the brilliant yellow ball almost directly in front of them at the time, DUH! The sun had been up for one hour and fifty-five minutes at their location crossing the equator at 30 degrees west longitude. (see attached chart.) On page 50 it goes on: "At “9:41” Natal time, on June 7, 1937, the sun azimuth from true north was 050.35 degrees, and its elevation above the horizon was +40.81 degrees. AE writes that “…they can hardly believe the sun is north of them.…” Their true course to Dakar was approximately 038 degrees. The sun would have been slightly to the right of their heading, south of their course, if they were on course. If they were heading in a more easterly direction, the sun would indeed appear north of them. From AE’s logs we know that AE was north of course at some point in the crossing. It is possible that these observations of the “…sun…north of them…” were made after a heading correction to rejoin their original track to Dakar. This heading correction would place the sun to their left, possibly appearing as if it was “north” of them." First, no navigator would give the azimuth to one-hundredth of a degree nor would he give the altitude in decimal degrees. This note was made six hours and twenty-eight minutes after takeoff and the plane was at 4° 30' north latitude. The sun was 22°38' north declination (latitude) so it WAS north of them no matter what their heading happened to be. The azimuth was actually 42° degrees not "050.35" and the altitude was actually 64° 31' not "+40.81." Page 54-55 compares the coordinates for Howland that Williams had used with the current charted coordinates. The were given only to the nearest minute, and accuracy of one nautical mile. Then is uses a Google Earth coordinate for the island and says the spot Noonan was aiming for was "5.92 NM" in error, a precision of one-hundredth of a nautical mile, 60 feet, on a bearing of "095.17 degrees." Some problems with this. Since the charted positions were only given to the nearest whole nautical mile it is silly to then compute distances to a precision of a hundredth of a mile. And it depends on what spot of the island they put the Google Earth pointer on. And the distance that they calculated Noonan would have missed the island by was computed from the center of the island when the near shoreline would have been the appropriate spot to use, cutting the distance by a half mile. And it is also silly to give a bearing to one-hundredth of a degree. They apparently computed this value with their calculator and don't have any idea of what the numbers actually signify, GIGO. It is also quite likely that Noonan had the correct coordinates for the island because Itasca had determined them after Williams completed his work but before AE departed on the second attempt. I don't think AE's student, Elanor Roosevelt would have kept that information from Earhart. Plus they ignore the glaring fact that Itasca was making smoke that drifted past the imagined wrong coordinates which would have been visible from the plane. Page 59 Makes the ridiculous statement that "Celestial fixes are much more accurate than a sun fix." This again shows a lack on knowledge of celestial navigation since the sun is a celestial body and fixes derived from shooting the sun are as accurate as any other celestial fix. Page states: Noonan sun line error exceeded "the standard 15-‐30nm accuracy of 1937 celestial navigation." I have no idea where they come up with such low accuracy unless it was on purpose to discredit the method. All navigational textbooks of the era consider the accuracy of celestial fixes to be approximately 10 NM and this level is also a requirement of the Federal Aviation Regulations. See the excerpts from "Weems" especially pages 422 to 425 which reprints a letter from Noonan himself stating his accuracy is 10 NM! This is available on my website at: https://sites.google.com/site/fredienoonan/ I could go on and on with additional examples but it should be obvious by now that I have serious doubts about the value of the Waitt report. gl --- On Mon, 4/25/11, Gary LaPook <glapook@pacbell.net> wrote:
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