The Air Crash damage is usually much too small to be used purposefully. Although the largest flying units: the Novax UEF Defense Satellite, the Cybran Experimental Gunship : Soul Ripper, Aeon Experimental Aircraft Carrier: CZAR and the Seraphim Experimental Bomber: Ahwassa can deal significant Air Crash damage, this is only a small bonus when losing the unit.
Only the most skilled player will purposefully use the Air Crash offensively, but only as an ACU snipe method or to eliminate high-value, low-health game ender units. Note that crashing units pass through shields (changed in FAF), and with the right units can wreak huge amounts of havoc, even if, and especially if a defending player has good anti-air capabilities. If the player does not have a very powerful defense grid, the attacking player can always hit Ctrl-K and end the game quickly. Again, this is a very small bonus in comparison to using a unit's attack capabilities the right way. Players must be careful when using this tactic, as they can inadvertently give the enemy a large amount of mass if their plan fails. The CZAR is by far the easiest unit to intentionally crash into a target. Crashing one into a game ender is often the best chance at staying in the game. Use of the CZAR's crash against the Aeon Paragon is one of the most common uses of the air crash, and can be the easiest way to take one out.