Aircraft Fuel Systems
Staff Sgt. John Bellardino, 28th Aircraft Maintenance Squadron aircraft systems craftsman, reviews technical data, work orders and aircraft maintenance procedures on the flightline at Ellsworth Air Force Base, S.D., March 8, 2012. Aircraft systems specialists are responsible for maintaining and troubleshooting internal hardware such as valves, lines, controls and other attachments to ensure aircraft remain operational. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)