362nd Training Squadron F-15 crew chief apprentice course students pose for a picture on top of an F-15C trainer jet at Sheppard Air Force Base, Texas, March 12, 2019. In 2010 Sheppard received a total of 13 F-15C and F-15D trainers to replace the older F-15A and F-15B trainers. Models C and D are the ones currently used in the operational Air Force. (U.S. Air Force photo by Airman 1st Class Pedro Tenorio)