Tech. Sgt. Pierre Julien, a crew chief from the 20th Fighter Wing at Shaw Air Force Base, S.C., configures navigation gear in the cockpit of an F-16 Fighting Falcon while sitting on the flightline of the Kentucky Air National Guard Base in Louisviille, Ky., on April 15, 2010. The aircraft is part of the U.S. Air Force Viper East Demo Team, which is in town to participate in Thunder Over Louisville this weekend. (U.S. Air Force photo by Senior Airman Maxwell A. Rechel)