You can get a guy to chuck a smoke nade where he is going to land. But I don't think.....hold on, what would be the cam create forsmoke nade ?:
flare1="smoke" camcreate[getpos dude select 0, getpos dude select 1,50]?
Still, if you did that, you would have to know where the heli is going to land before hand.
O Neil