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    Re: Mr. van Asten
    From: Gary LaPook
    Date: 2013 May 3, 00:27 -0700
    There is an American expression that "a little knowledge is a dangerous thing." It is dangerous thing because a person with "a little knowledge" thinks he knows more than he actually does, he doesn't know the limits of his bit of knowledge. A person with no knowledge knows that he has no knowledge and so does not undertake to make decisions about those areas, he hires a person who is knowledgeable for that.

    Van Asten is fixated on a "sunrise observation" (as are others in the Earhart searchers club) and this fixation comes from having a "little knowledge" of celestial navigation. This fixation comes from looking at Earhart's last radio transmission mentioning the 157-337 LOP and, having enough knowledge to know that LOPs run at right angles to the azimuth of the sun, he computed the azimuth of the rising sun, which turns out to be 067, (67 + 90 = 157) degrees so van Asten said "ah ha" I am right, they were flying along a sunrise derived LOP. But, Mr. van Asten (and others) didn't realize that the sun's azimuth remained 067° until 1847 Z, more than an HOUR after sunrise so Noonan could have taken his observation anytime within the entire period and he would still derive the same LOP of 157-337. The sun's azimuth changed only one degree to 066 in the succeeding 36 minutes, until 1923 Z, well past the "must be on you" transmission at 1812Z.

    Mr. van Asten also did not know that Noonan refraction table only provides the correction factors for measurements of 6 degrees or greater and without corrections for lower altitudes Noonan could not accurately compute anything from a lower measurement. Assuming the plane was still at 10,000 feet, the rising sun actually appears 1 degree and 37 minutes  BELOW horizontal (-1.6 degrees), fully 7.6 degrees below the minimum observation that Noonan could take. (Correction tables for this situation did not become available until many years later.) From these modern tables we see that the correction needed is 42 minutes (0.7°) greater than the lowest value tabulated in Noonan's tables for an altitude of + 6°. This would produce an error in the derived LOP of 42 NM. At 1847 Z (when the azimuth was still 067°) the sun was already 13° 20' high, more than seven degrees above the minimum 6°. The sun climbed above the required six degrees by 1815 Z, a half hour after sunrise so he had the following 32 minutes to take several additional solar observations each of which would produce the identical 157-337° LOP.

    See:  https://sites.google.com/site/fredienoonan/discussions/the-myth-of-the-sunrise-lop

    Mr. van Asten also says that he had a technical career and this brings up another issue. Many technically qualified persons mistakenly believe that they are experts in other areas, areas outside of their actual, limited area of expertise. I have encountered this many, many times in my practice of aviation litigation. All my cases involved technical issues and every party had to hire many high priced experts to testify about each of these technical issues. One of the things I truly loved about my job was taking these "experts" apart on the witness stand under cross-examination when they ventured into areas in which they were NOT expert. It was fun. Mr. van Asten should stick to the area in which he might have some expertise and leave flight navigation to people knowledgeable of that technical area.

    gl
       
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