Airmen from the 28th Aircraft Maintenance Squadron perform a foreign object debris (FOD) check along the flight line during Red Flag 21-2 at Nellis Air Force Base, Nev., March 9, 2021. Red Flag is one of the Air Force’s largest combat training exercises. This year’s iteration includes participants from a dozen states, Singapore, Sweden and seven NATO member nations. (U.S. Air Force photo by Staff Sgt. Hannah Malone)