there are clever ways to get around the problem: you can overlap different recordings at different RPMs, all you need is an idle, a 50% and a full throttle.
Considering the limited number of planes in CoD at the moment and the availability of recorded engine sounds available today, it's completely unjustifiable not to have them ingame.

Same goes for machinegun sounds and that horrible "submarine creak" going on when pulling too many Gs. Maddox Games should pay attention to these things, just like the quality of their textures, which I'm sorry but

1) it's low resolution compared to what we see in other sims

2) it's (and I'm sorry for who's behind it) not up to the current standards. We have way more talented skinners out there who enhanced the quality of our old IL-2 incredibly.