The Reading and Pittsburgh units were equipped with F-51D Mustangs, with a mission of air defense of the Commonwealth. The 111th Bombardment Group in Philadelphia was equipped with B-26 Invaders, assigned to Tactical Air Command as a light bombardment unit. The 53d Wing was also the headquarters for an Aircraft Control & Warning Group (AC&W Gp)located at Harrisburg State Airport and three Air Service Groups, which were colocated with its flying groups and had flights located with each of the squadrons assigned to the flying groups.