As the USAF prepared for deploying the E-3 Sentry in the later 1970s, it phased out EC-121 operations by the end of 1975. All remaining EC-121s transferred to Air Force Reserve, which formed the 79th AEWCS at Homestead Air Force Base, Florida in early 1976. The active duty force continued providing personnel to operate the EC-121s on a 24-hour basis, assigning Detachment 1, 20th Air Defence Squadron to Homestead AFB as associate active duty crews to fly the AFRES-owned aircraft. Besides monitoring Cuban waters these last Warning Stars also operated from NAS Keflavik, Iceland. Final EC-121 ops ended in September 1978. Detachment 1 dissolved and 79th AEWCS was redesignated a fighter squadron on 1 October 1978.