NavList:

 Gary you said:

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-Your method works when you can plot all of your LOPs from one assumed position using a calculator or HO214 or HO 211, or Bygrave computor, or HO 249 volume 1 with MOB and MOO adjustments, or any other method that allows computing from a DR or known position. I think everybody on navlist has taken observations from a known position in order to practice with his sextant, obtaining the known position with GPS, since this allows evaluating the quality of the sextant work. So you end up with a fix that is plotted in relation to the AP and you take out the north component and add it to your assumed latitute and then you see the distance to east or west and convert that distance to difference in longitude by using the secant of the latitude (either from your calculator or, HORRORS! from a trig table, remember those) just like you did. You can also do this convenienly on your E-6B, see attached pages from AFM 51-40.

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It is funny how these threads come full circle.  David C. in New Zeland was doing just that - practice shots from a fixed location on land and said you could not plot an azimuth on plain paper which I took to mean that he believed he needed to have a Mecator or Lambert or some other map projection to plot an azimuth and a LOP from one fixed point.

John H.

As an aside - My nephew flew F-14s and his small computer was not a E6-B like mine. His had no slide on the back but was round. Do you know if it was a Navy version of a CR computer or something else?  JH