Airstrike

An airstrike is a type of tactical air support in which airborne vehicles attack a target, usually on the ground.

In game
In Call of Duty 4: Modern Warfare, players who kill five enemies in a single life may call in an airstrike. An airstrike can only be called in if there is not another airstrike in progress. When the player calls in an airstrike, he must select the target area. On maps where there is little cover, like Bog and Shipment, airstrikes can kill many enemies.

The airplanes that drop the bombs for the teams are three F-14 Tom cat's, They are also seen in the single player mode.

They can cause damage through very thin materials (like the awnings in District). On maps with mostly indoor areas or many buildings, airstrikes are best used on the center of the map.I recommend that, in cases where the enemy positions are known, that you lead the target, as the air strikes take a while to arrive and thus could miss a target that was in the center of the reticule during the aiming stage.

Air support doesn't stack, so if you get an air strike, use it before attempting to get a chopper, as it is removed upon getting the next one up, however, lower-tier air support does replace higher-tier, Choppers ARE overwritten by UAV.