Instructions
Scroll down to "Airstrike" in the on-screen menu. Depending on which mission you are playing in, "Airstrike" could also appear as "Apache" or "Artillery."
Point your cross hairs at the target to call in the airstrike.
Pull up the cross-com menu by hitting "R2" on a PlayStation, pressing the "G" key on a PC or pushing up on the D-pad on an Xbox once airstrike has been selected.
Select the "Attack" option while still aiming your cross hairs at the target.