FFF / Fly Stimulator - I agree that the 'classical' calculations are probably fair estimations, but when I first read budipro's question, for some reason, I started thinking that this will not give an exact answer. The map projection is, of course, an approximation (based on a specific projection technique, such as Mercator, etc). Technically, I would have thought that the precise answer requires calculation using
Spherical Geometry and taking into account the altitude (as this will affect the circumference of the circle that the pilot is flying along).
For short distances / lower altitudes, this will not be significant, but for trans continental flights at the altitudes used by heavies, this must surely be factored in.
Maybe I'm barking up the wrong tree and will be shot at dawn for fundamentally misunderstanding all my PPL Nav training, but I'll risk it for a biscuit!!