The damage that an aircraft causes after destruction, upon crashing on the ground. Has a damage radius.
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. Note that crashing units pass through shields, 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.