362nd Training Squadron KC-135 crew chief apprentice course students work on the refueling boom nozzle of the KC-135 Stratotanker at Sheppard Air Force Base, Texas, Sept. 27, 2018. The students are working on securing the safety wires of the boom nozzle before it is retracted. The boom nozzle is often modified depending on which aircraft it will be refueling during that mission and must be secured with the safety wires to keep the parts together. (U.S. Air Force photo by Airman 1st Class Pedro Tenorio)