F-15 Strike Eagle aircraft from Seymour Johnson Air Force Base, N.C., taxi before flight May 3 at Hill AFB, Utah. The F-15s, along with other fighter and bomber aircraft, participated in the U.S. Air Force air-to-ground weapons evaluation known as Combat Hammer. Combat Hammer, which runs until May 14, tests and validates the performance of crews, pilots and their technology while deploying precision-guided munitions. (U.S. Air Force photo by R. Nial Bradshaw)