U.S. Air Force Staff Sgt. Josh Underwood, center standing, teaches F-16 Fighting Falcon tactics and aerial refueling procedures to Bulgarian and Romanian air force personnel during the first Bulgarian command and control training course in Sofia, Bulgaria, May 30, 2018. Underwood is a weapons director assigned to the 337th Air Control Squadron from Tyndall Air Force Base, Florida. Air Force photo by Senior Airman Preston Cherry