Airman 1st Class Webb Travis uses tungsten inert gas to weld a panel for a bomb loader during repairs Jan. 26, 2011, at Ellsworth Air Force Base, S.D. Tungsten inert-gas welding is a precise form of welding that can be performed on a variety of metals. Airman Travis is an aircraft metals technology technician assigned to the 28th Maintenance Squadron. (U.S. Air Force photo/Senior Airman Kasey Close)