362nd Training Squadron F-15 crew chief apprentice course students work and talk on top of an F-15C trainer jet at Sheppard Air Force Base, Texas, March 12, 2019. The F-15 maintenance course covers five blocks of instruction over fighter aircraft fundamentals, egress, airframe, weapons, electrical, avionics, utility systems, hydraulics, landing gear, flight controls, engines, engine starting systems, and inspections over a span of 69 academic days. (U.S. Air Force photo by Airman 1st Class Pedro Tenorio)