Airman Joseph Rhym, left, reads instructions to Airman Jack Gagnon, 364th Training Squadron electrical and environmental apprentice course students, as they work on an F-15 Eagle at Sheppard Air Force Base, Texas, Oct. 5, 2018. Gagnon and Rhym are working on removing and installing an oxygen regulator in the flightdeck of the aircraft. E&E systems technicians are responsible for several components in almost every aircraft in the Air Force, excluding the newer F-22 Raptor and F-35 Lightning II. (U.S. Air Force photo by Airman 1st Class Pedro Tenorio)