U.S. Air Force Airman Gianni Galvan, 51st Civil Engineer Squadron heating, ventilation and air-conditioning technician, practices on a HVAC training system at Osan Air Base, Republic of Korea on August 9, 2017. Aside from day-to-day operations, the Osan HVAC shop has about five, first-term, Airmen that are responsible for completing their primary duties and stay current on their upgrade training. (U.S. Air Force photo by Airman 1st Class Gwendalyn Smith)