ATC making the pieces fit like Tetris
U.S. Air Force Staff Sgt. James Mackmer, 51st Operations Support Squadron air traffic controller, checks his systems as an aircraft awaits for departure at Osan Air Base, Republic of Korea, Oct. 4, 2019. Air traffic personnel controls and regulates en route and terminal air traffic, which they initiate and issue ATC clearances, instructions, and advisories to ensure the safe, orderly and expeditious flow of air traffic operating under instrument and visual flight rules. (U.S. Air Force photo by Staff Sgt. Ramon A. Adelan)