Reduce helicopter repair speed. I think it's fair that helicopters can be repaired by onboard mechanics, but the speed at which they repair, combined with flares, means that unlike tanks, they can be piloted for almost an entire game. In addition to skilled piloting in large maps this makes it so that it becomes hard to get a lock on a heli, when you eventually do land a couple hits they don't do anything because within 30 seconds the heli is fully recovered. When paired with a skilled pilot, it completely unbalances the game especially in iceland where the mechanic has to carry RPG to deal with two tanks, and not everybody will want to play engineer, so there is simply nothing you can really do against a pilot if they want to go 40+ kills with only a handful of deaths. Other suggestions for anti air would be allowing the assault to carry an anti air weapon, allowing sniper to have a tracker dart which would enable instant lock on for a moderate duration provided they can get a shot onto the copter, fixed point anti air cannons in A and C iceland, and fly-by-wire rocket as a new rocket for mechanic which could tackle both tank and copter although take more skill and leave the mechanic vulnerable.