[Redwulf__32]

Google uses WGS-84 too... this is a geodetic system (someone call datum), not a projection.

I believe Il2 maps are not projected, but represented as a ellipsoid part (roughly saying, "as is") This is due when you flying earth is not plane, but curved as you flying above an sphere (or ellipsoid).

As real coordinates are not represented in IL2 maps, we can't determine what projection or datum this uses. But i believe earth's curvature is so exagerated in IL2 (you can see earth spherical at 5000 m for example, and this is not true).

Absolutely right !

Those kind of things would be more documented if someone could decompile the Java code and make it readable...

Having the complete source code would be nice 8) Many things could be rectified/brought up-to-date.
However, I doubt the IL2 engine does any projection calculations, my guess is it simply presents the map info on a flat world.

Regarding the "earth curvature" seen at higher altitudes, what you actually are seeing is the limit of your visibilty sphere (which is seen as a circular segment of the ground). You can see this phenomenon in real life on a hazy day at higher altitudes flying below the tropopause (the stratosphere is not hazy).

Thnx for clarifying my datum/projection confusion, now I know how to correct the coastlines so they'll fit on the HGT based maps.