Destroying ground units::
Instead of the laser-guided AGM-114K Hellfire II, equip your Apache helicopter with radar-guided AGM-114L Hellfire missiles during the arming phase. The AGM-114L missile is specifically designed for Lock On After Launch (LOAL) capabilities, which allows you to fire at ground units from behind cover without exposing your helicopter to enemy fire.
Destroying air units:
When you run out of air-to-air missiles, chain guns and guided missiles can be used against both fixed-wing and rotary aircraft. Try engaging enemy aircraft from behind cover and at the shortest possible range, preferably just ahead or slightly behind the aircraft using a low-angle deflection shot.