Brookfield Air Force Station constructed as part of the Air Defense Command permanent network it was opened in April 1952. The 662d Aircraft Control and Warning Squadron began operations with AN/FPS-3 and AN/FPS-5 radars, and initially the station functioned as a Ground-Control Intercept (GCI) and warning station. As a GCI station, the squadron's role was to guide interceptor aircraft toward unidentified intruders picked up on the unit's radar scopes. This operation allowed Lashup site L-18 at Ravenna, OH, to shut down. In 1957 the AN/FPS-5 height-finder radar was replaced with an AN/FPS-4, and then the AN/FPS-4 was replaced with an AN/FPS-6 in 1958.