without any permanently assigned interceptor squadrons, however ADC rotational F-106 deployments continued. Despite a diminished number of personnel and aircraft, the arrival of the 43d Tactical Fighter Squadron in June 1970, from MacDill AFB, Florida with McDonnell Douglas F-4E Phantoms. The squadron gave AAC an air-to-ground capability that was further enhanced with the activation of the 18th Tactical Fighter Squadron at Elmendorf, also with F-4Es. The arrival of the versatile F-4E marked another turning point in AAC's history. It gave AAC a tactical air-to-ground attack capability. Consequently, the rotational ADC F-106 deployments from the lower continental states ceased soon after the 43d assumed mission responsibilities at Elmendorf, Eielson, Galena and King Salmon on 1 August. The winter of 1970–1971 was severe in Alaska, causing numerous mechanical failures in the F-4s which had been accustomed to Florida's warm climate. At times, the wing's operational air defense assets dwindled from eighteen aircraft to only one or two. Moreover, the 43d assumed close air support as well as air defense responsibilities, two missions which stretched the squadron's capabilities. In response, Air Staff sent the 43d an additional six aircraft in May 1971. Organizational changes also underscored the 1970s. Due to a realignment of airlift and rescue forces under the Military Airlift Command (MAC), the wing divested its helicopters and C-130s in 1975. Overall, however, the wing expanded, gaining two air base squadrons and several other responsibilities. The 21 CW picked up a new fighter unit on 1 October 1977 when the 18th Tactical Fighter Squadron (F-4Es) activated. Subsequently, the 43d maintained its air defense mission while the 18th adopted the role of close air support. Both units shared air defense alert duties in Alaska. Additionally, from November 1977 to April 1979, the 21st CW controlled all thirteen of Alaska's air control and warning sites 1980s modernization The 1980s were a period of growth and modernization. The Command's command, control, communications and surveillance system underwent a modernization during the late 1970s and early 1980s. The labor-intensive, 1950s era Aircraft Control and Warning radar stations were replaced with minimally attended AN/FPS-117 long range radars, and the stations were closed in 1983; being reduced to unmanned sites supported by contract civilian personnel. The White Alice Communications network was inactivated in 1979, being replaced by an Alascom owned and operated satellite earth terminal as part of an Air Force plan to divest itself of the obsolete radio