7/11/2012 - A KC-135 Stratotanker sits on the flight line as the sun sets at McConnell Air Force Base, Kan., July 10, 2012. The KC-135 provides the core aerial refueling capability for the U.S. Air Force, and has been performing in this role for more than 50 years. (U.S. Air Force photo by Lt. Col. Travis Clark)