From what I can see, you really need to sort out your smoothing groups. IL-2 takes the shading etc directly as you see it in Max. The *ahem* special project I am working on at the moment was a dog in this respect. I ended up de grouping, unwelding, re grouping and re welding pretty much everything in Milkshape 3D, then and only then was the mesh smoothing tool in Max of any use to me.
It looks to be a good solid model, though. What is the poly count?