I don't know what I'm doing wrong but I've been playing co-op on this one. We get to the crew and start to extract but they always get shot. Do I need to give the crew a specific command to start going to the extraction point or what? I've played it to this point about 5 times and they always get shot.

I hated that one. You'll have to start over. Keep the one air strike you get. before grouping up with the pilots, clear the town,then use the strike in the tree's near the building there in,this will kill most of those enemies. finsh those off. now link up and order you're men to follow you. they'll go with the pilots. You need to take out the apc firing on you or the pilots will get killed. after that just run like hell, but stay with the pilots. incase a heli or missed squad fires on you.
Let me know if this helps.

As soon as you get to the pilots, just run. Don't bother trying to kill everyone. If you're quick enough, the APC won't even bother you and the only thing you'll to deal with is the guys that get dropped by the chopper.

Thanks for the replies. I'm going to give it another shot for the umpteenth time.