NavList:

Thanks for trying this Hew!

 

I'm a big confused how you get the number "152 nm?"  The 1112 sight has an HO of 88 deg 06'.  That should equal a zenith distance of 1 deg 54' or 114' minutes/nm.  The 1121 sight has a Z-dis of 86.1 minutes/nm.  The only thing I can think of is that you have a different method of advancing the LOP's to noon?

 

I'll post the correct answer with my method of solution in a few days.

 

Jeremy

 

Your example from the CG test intrigued me because it's a case of
altitudes so high you can put the GPs down on a plotting sheet, swing
the arcs of the zenith distances and use the DR to choose which of the
two points where the arcs intersect to decide which point is the fix.

I did this on a VP-OS Universal Plotting Sheet - the one where a NM is
about one millimeter. Because I don't have a compass large enough to
draw an arc with a radius of over 152 NM, I couldn't change the scale.

Anyway, I came up with a position of 19*22' S, 6*38' E, which is very
close to the 1200 DR of 19*20.3' S, 6*39.3' E. Closest position on the
answer sheet is A.

Check me on this, if you've got the time.

Thanks, HewS