Ellsworth Airmen participate in a foreign object debris walk at Ellsworth Air Force Base, S.D., May 1, 2015, where they cleared the flightline of potentially hazardous debris. FOD is a leading cause of aircraft damage throughout the Air Force, totaling more than $500 thousand dollars since Jan. 2015 at Ellsworth. (U.S. Air Force photo by Airman 1st Class Rebecca Imwalle/Released)