il-2 Compare for 4.09m

[Buzpilot]

, and I don't think there is a systematic error in IL-2 due to any miscalculation.

I'm not sure, if the formula in example #5 is correct( It say; Normally accurate to within 5 Knots.), it indikate just that.
And many planes in real life ww2 had their best combat altitudes above 20 000 feet, but nobody makes missions at those altitudes in IL2, not just because it takes a while to get there, imho .

Edit; I don't think this is a error, but maybe too simplified, and after comparing lots of planes in il2compare, I was amazed of the amount of data in flightmodels, and it probably would get even better with more advanced IAS calculation.