A U.S. Air Force E-3 Sentry airborne warning and control system aircraft soars over Nevada after a refueling mission during exercise Green Flag-West 13-02 at Nellis Air Force Base, Nev., Nov. 1, 2012. The aircraft is assigned to the 963rd Airborne Air Control Squadron, Tinker Air Force Base, Okla. (U.S. Air Force photo/Val Gempis)