A typical Soviet "frontal aviation division" consisted of three air regiments, a transport squadron, and associated maintenance units. The number of aircraft within a regiment varied. Fighter and fighter-bomber regiments were usually equipped with about 40 aircraft (36 of the primary unit type and a few utility and spares), while bomber regiments typically consisted of 32 aircraft. Divisions were typically commanded by colonels or major generals, or colonels or major generals of aviation in the Air Force. Soviet Naval Aviation and the Strategic Missile Forces divisions had either colonels or major generals as commanding officers while the ship divisions were led by captains 1st rank or captains 2nd rank.