U.S. Air Force Airman 1st Class Tristan Blake, a 35th Operations Support Squadron airfield systems technician, performs a check on an instrument landing system at Misawa Air Base, Japan, Feb. 28, 2017. The ILS provides horizontal and vertical guidance for pilots landing and taking off. Airfield systems technicians periodically perform preventative maintenance inspections on equipment to ensure serviceability. (U.S. Air Force photo by Airman 1st Class Sadie Colbert)