Thanks Gary! Think I may still flunk this class but at least i'm trying.
I see how a LOP works and understand that without reference points then yes you would more than likely struggle to stay on the line. It wouldn't stop you from getting there with some good fortune and luck though.
In simple terms why do the lines change from 157 to 153, 148 and finaly 126? re read again and had a light bulb moment.
Can you not navigate a LOP and take into account the counter clockwise rotate centred on Howland? Thus keeping along the LOP. Otherwise by the looks of it TIGHAR should be looking on Kanton not Niku 
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On January 15, 2003 I posted this challenge to the navigation experts on the TIGHAR forum:
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Date: Wed, 15 Jan 2003 13:39:33 EST
From: Gary LaPook
Subject: Re: Marshall Islands and LOP
You are right Alan, the line on his chart would not move.
However the only value of a LOP is that it represents a line on the surface of the earth. We both agree that there was no LOP painted on the water that Noonan could see and follow. It was not a terrestrial line of position like a railroad track, road, river or shore line that a pilot can follow to an airport located next to such LOPs.
The celestial LOP is useful for finding an island if the line on the chart passes through the island and so representing a line on the earth's surface that also passes through the island. Then, if you can determine that you are staying on the line on your chart you will also be determining that you are staying on the line on the surface of the earth that goes to the island. You make this determination by taking additional observations of the sun and comparing the altitude that you measure to the altitude you would have measured (which you compute) if you were on the LOP. If they are the same you are on the LOP, if not you can determine how far off you are and which way to turn to regain the line.
The question I have about your response relates to your statement:
>He would check
>his position periodically in relation to the line he had drawn on
>his chart. A line that never moved.
I don't know how he does this after the sun's azimuth has changed, perhaps you can explain it to me. Use this example to check his position in relation to the line he had drawn on the chart:
It is now 2240 Z on July 2,1937, about two and a half hours after the last transmission, and the airplane has been maintaining a true heading of 157 degrees and an airspeed of 120 knots and so should be getting close to Gardner. Noonan uses his bubble sextant and measures the altitude of the center of the sun. After making corrections for refraction and index error his observed altitude (Ho) is 59 degrees 15 minutes.
Where is he in relation to the line he had drawn on the chart?
Is the plane still on the LOP drawn on the chart?
If the plane is not on the line on the chart then how far off the LOP is the airplane?
Is the plane still on course for Gardner?
If it is not on the line to Gardner then which way should he turn to get to Gardner?
Please explain how you reach you conclusions and include the math.
If you have a scanner available I would appreciate it if you could scan in the chart work you do to figure out this example and email it to me at : glapook@pacbell.net since I would like to see how you accomplish this.
gl
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It's been 8 years and 7 months and still no serious response.
So, to answer your question,
no you can't just make some compensation for the change in the azimuth of the LOP and then use it to find Gardner.
gl
