A U.S. Air Force Airman crew chief with the 1st Aircraft Maintenance Squadron marshalls an U.S. Air Force F-22 Raptor at Red Flag 17-4, Nellis Air Force Base, Nev., Aug. 10, 2017. Red Flag is a realistic combat training exercise involving the air, space and cyber forces of the United States and its allies. (U.S. Air Force Photo/Staff Sgt. Carlin Leslie)