Airman 1st Class Collin Dunn, 28th Logistic Readiness Squadron fuels laboratory technician, weighs a bottle method filter pad during fuel testing at Ellsworth Air Force Base, S.D., March 22, 2012. The filter collects any impurities, such as sediment and particulates, that could lead to aircraft malfunctions and compromise safety. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)