The air refuelable B-52 brought with it a return of the air refueling mission, this time with the Boeing KC-135 Stratotankers of the 6th Air Refueling Squadron. SAC was expanding the number of its B-52 wings, increasing the number of B-52 crews it had to train. On 1 August 1959, the 4129th Combat Crew Training Squadron was organized and assigned to the wing to conduct ground training of new crews, while the following month, the 24th and 39th Bombardment Squadrons began flying training.