The Thunderhawk transport/gunship is one of the Space Marines' primary weapons in the war against the enemies of the Imperium. It is capable of both atmospheric and space flight as well as combat, and can transport three full Tactical squads of 10 Marines each.
Each Chapter maintains its own Thunderhawks. Normally reserved for large-scale battles, time and time again its use in the various fields of war has been proven. With such might, only a great threat to the Imperium would cause a demand for the use of these great craft.