The 3rd Air Division was activated in September 1943 as an intermediate command and control organization between command and wing levels. It was assigned to VIII Bomber Command, Eighth Air Force. The Division commanded three combat bombardment wings (4th, 13th and 45th), consisting of seven B-17 Flying Fortress bomb groups. The addition of the 92nd and 93rd Combat Bomb Wings in 1944 and additional bomb groups to the other wings increased the number of combat groups to fourteen. Between May 1944 and September 1944 the division operated both B-17 Flying Fortress (nine groups) and B-24 Liberator (five groups) aircraft, before converting to an all-B-17 organization for the remainder of the war. In September 1944 the 66th Fighter Wing was assigned directly to the division for fighter support.