New aircrafts always provide an incentive and variety in the progression of a career.

So it would be cool to introduce a number of minor aircraft variants with different gunsights (various kinds of iron sights, and telescopic sights if and when applicable) and/or marginally better performance (representing a more finely tuned engine, for example).

Introducing quite a few variants should be relatively straightforward, with only minor modifications of the 3D or FM models. It would be cool if the different variants could be made available to the player according to his proficiency as a fighter (i.e. number of kills, decorations, etc.)