Senior Airman Jonell Sanchez, an air traffic controller assigned to the 28th Operations Support Squadron, transfers beacon codes during a training simulation at Ellsworth Air Force Base, S.D., Jan. 25, 2017. The Ellsworth approach display shows aircraft entering the airspace and allows the controllers to communicate with the pilots. (U.S. Air Force photo by Airman 1st Class Donald C. Knechtel)