Tech. Sgt. Sam Gordon (center), 437th Maintenance Squadron aircraft fuel systems section chief, gives direction to Senior Airman Brett Jones (left), 437th MXS aircraft fuel systems journeyman and Airman 1st Class Nicolas McKinney (right), 437th MXS aircraft fuel systems apprentice, moments before a training exercise March 7, 2013, at Joint Base Charleston – Air Base, S.C. Fuel System Repair Airmen maintain the fuel cells and tanks by removing, repairing and installing the cells and tanks. The Airmen also clean the cells and tanks, inspect for corrosion, cell deterioration, fungus and foreign objects. (U.S. Air Force photo/Airman 1st Class Tom Brading)