Programmed depot maintenance modernizes KC-135s
A KC-135 Stratotanker undergoes programmed depot maintenance at the Oklahoma City Air Logistics Complex at Tinker Air Force Base, Oklahoma, Nov. 23, 2019. During PDM, each KC-135 undergoes a series of inspections, upgrades to the aircraft, and a flight test to ensure proper functionality. (U.S. Air Force photo by Airman Kiaundra Miller)