Nothing is more satisfying than hearing "Copy That" as your shot marks where Bombs will be dropped from the sky from an unseen source, blasting your enemies!
Air Strike is the first flare type weapon unlocked in the game. When fired, it acts similarily to a grenade in the sense that it bounces about, but that is the extent of the similarities. After it stops moving, 3 bombs fall from the sky in close accord, with a decent explosion radius that makes it highly likely for multiple shots to hit. Of the weapons in the family, this is the most all-around weapon, and is generally good in any situation.
Helicopter strike is the first upgrade to Air Strike. It is also a flare weapon, and it deals the same amount of damage per hit. However, the bombs dropped are much more numerous and closer together than the Air Strike, and the explosion radius is much smaller than the air strike. This weapon sacrifices damage for the largest horizontal area of effect in the family.
The AC - 130 function is the same as an Air Strike, however its weapons deal much more damage (the largest in the family) and have a slightly larger explosion radius.
Artillery drops 3 bombs from the sky, dealing damage and greatly damaging the terrain. To guarantee maximum destruction, the bomb drops are ordered and delayed, with the center bomb dropping first, followed by the leftmost and then the rightmost. This weapon is the most destructive, and can easily force your enemies into the bottom of the map.
Out of all the 4 tiers, the name suggests it comes from artillery and not from an aircraft.
The Air Strike family are all Flares, meaning that they won't activate until they stop almost all movement, and won't bounce as far as grenades. Because of this, they are slightly more usable on slopes and slants, but are still not recommended on steep curves.
Perhaps the most versatile of the starting weapons, each tier of weapon is intended to be used in different ways than the others, as opposed to other weapons where each level expands on the power of the prior levels. Learning when to use all of these is the difference between 20 damage and 90 damage.