U.S. Air Force Senior Airman Ben Jenkins from the 446th Civil Engineer Squadron helps re-spool a broken pull cord on an asphalt grinding machine during a field exercise at Tyndall Air Force Base, Fla. on March 23, 2011. Airman Jenkins is one of 30 Reservists from the 446th CES participating in Silver Flag 2011, a training exercise designed to improve the readiness capability of Air Force civil engineers. Airman Jenkins is a heavy construction equipment operator with the 446th CES. The Tillamook, Ore. native is an applied sciences student at Portland Community College in his civilian life. (U.S. Air Force photo by Staff Sgt. Grant Saylor/Released)