Airman 1st Class Brody Schneider, 28th Operations Support Squadron air traffic control technician, executes a simulation during training on Ellsworth Air Force Base, S.D., April 19, 2012. Airmen are required to train, perform simulations and be evaluated before they are fully certified as a controller. (U.S. Air Force photo by Airman 1st Class Alystria Maurer/Released)