Airman 1st Class Collin Dunn, 28th Logistic Readiness Squadron fuels laboratory technician, seals a bottle method during an aircraft fuel test in the Fuels Lab at Ellsworth Air Force Base, S.D., March 22, 2012. The seal ensures nothing enters the bottle, filters, or fuel during the test, for accurate results. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)