The AC-4 is a small Aerolyth platform designed for troop transport and assault missions against the Hive. The AC-4 was ordered by Army Aviation Squadrons (Close Support Group) in Febru-ary 1898 as part of a “crash program” to reequip the US Army for the fight against the Second Hive. It focused on an array of quick-firing weapons for offense, and an unusual armor scheme for defense. The vehicle’s armor was made from steel covered with a 2cm layer of elm on the outside. Unlike conventional armor, which sometimes used wood internally to blunt and spread the force of a shell’s impact on the outer steel, it was thought that this could provide more pro-tection against the long claws of the Hive creatures.