Oh for pitty sake! 1.5 is one and a halh kilometers! Snipers can shoot 1,000 meters with a barrets... at a man sized target. Granted they got these God zoom scopes. but I digress
At 2 kilometers, if you can not make out a volkswagon bug, or microbus, then you are blind.
In the air, I know I can pick out small trailers, and vans at 1.5 kilometers regularily... some of these in wooded areas, mind you. That's not quite two miles. Fighter sized planes can be ID'd by the mK1 Eyeball from 1 to 2 miles depending on aspect angle.
HT has the ranges pretty accurate in here from D5 down, IMHOAE (in my humble opinion and experience) If you can't tell a bogey from a freindly at 5,000 meters then somehting is wrong withe the mK1 eyeball.
Keep in mind too, that the D ranges take into account certain aspects of the strategic and tactical situation. Your side knows where their planes are supposed to be. If a con shows up outside of those parameters, then it's a pretty good bet they're bandits.
It's those 49k kilometer ranges that annoy me in another game.
sorry for the rant, but we had a really heated discussion on this topic in another historical arena recently.