Crews for this unit were acquired from the 393d crews not selected to continue B-29 training, most of whom chose to remain with the 509th rather than be assigned to a replacement pool of the Second Air Force.
Crews for this unit were acquired from the five 393d crews not selected to continue B-29 training. All those qualified for positions with the 320th chose to remain with the 509th rather than be assigned to a replacement pool of the Second Air Force.