The 478th Aeronautical Systems Wing is an inactive wing of the United States Air Force which was last based at Wright-Patterson Air Force Base, Ohio, where it was inactivated in 2009. The wing was first organized as the 478th Fighter Group (Two Engine), which briefly served as a Fourth Air Force Replacement Training Unit in 1944. The unit was disbanded when the Army Air Forces reorganized its training units into AAF Base Units to reduce manpower requirements in the United States.