Quote:
Very early in the thread someone made the point that 3 degrees is 324' /nm. Personally I use 320; it's easier on the grey matter. What it ain't is 300'/nm. Thus all the talk about 13nm = 3900' is not quite accurate. It is at least
4160' and could be higher if 324'/nm is correct
Well as a matter of fact, using the international standard of 1nm=6080ft, 1d slant range equates to 318ft. But since the earth is not a sphere, it is actually 316ft at the equator and 320ft at the poles (all figures to the nearest whole foot).
All of which is stupendously unimportant. 300ft per nm is far easier on the grey matter and quite good enough for all practical cross-check purposes!