Alright i am in Campaign Mode and I am completely stuck, and am starting to get rather heated. I know there is a simple answer to my problem, but for some reason i can't figure it out.
I'm trying to hold ground and protect VIP 2 while reinforcements arrive. I hold ground from the onlslaught of fighters, but then the ****ing tanks come. 2 of them are right outside and i cannot get rid of them. The apache comes and says just aim the gun and i'll take care of them, but i have no idea how to aim the apaches gun to destroy the tanks. How do you aim the gun?