I've lost count of how many choppers I lost in the mountain region south of khasab in PG (reminds me of afghanistan so I use that area with the A-10 for strikes).... and the funny thing is that when they manage not to crash on the side of a mountain, they actually get destroyed by enemy tank fire!!! Why the hell do they get that close???
Fighters AI in dogfights in valleys is equally hilarious, at some point they think they are going to hit something and pull up for no reason... getting to a near stall and becoming a stationary target for my cannon ... and if someone else is pursuing you at low level, this will take the direct route to your position, with a 40% chance of hitting a mountain.
(i have modified the Intercept quick mission with the su-27 to become a me vs 4 f-16 and 4 f-15, and I love it! It became the dogfight paradise around the caucasus highest mountains, and these funny situations really are around the corner, also i deleted my wingman because he liked mountains too much...)