Vermont Air National Guardsman Staff Sgt. Josh Mitchell, an F-16 Fighting Falcon avionics technician assigned to the 158th Fighter Wing, Burlington Air National Guard Base, Vt., performs a Global Positioning System operations check on an F-16 during Red Flag 15-1 at Nellis Air Force Base, Nev., Feb. 4, 2015. Red Flag is a realistic combat training exercise involving the air, space and cyber forces of the U.S. and its allies. It is conducted on the bombing and gunnery ranges on the Nevada Test and Training Range. (U.S. Air Force photo by Senior Airman Thomas Spangler)