Within five minutes of starting mission 5, "Homecoming", you will be attacked via the beach. You must defend your position using the mini-gun. Two to five minutes later, lay down when a helicopter begins spraying bullets at you. After the helicopter does this, you will have the ability to use the A-10 Strafe Run.

Run 1: Aim for the helicopters and surrounding troops.
Run 2: Shoot the beach that is almost full of enemies.
Run 3: Shoot the tank and surrounding beach.
Run 4: Destroy two tanks on beach and lone helicopter.
Run 5: You will only get this if you do not destroy the helicopter or tanks in time.