Mount Lemmon Air Force Station (ADC ID: M-92, NORAD ID: Z-92) is a closed

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Si ...

General Surveillance Radar station. It is located north-northeast of

Tucson, Arizona , "(at the) base of the black ill , nicknames = "The Old Pueblo", "Optics Valley", "America's biggest small town" , image_map = , mapsize = 260px , map_caption = Interactive map ...

. It was closed in 1969.

History

Mount Lemmon Air Force Station was established in 1954 by

Air Defense Command Aerospace Defense Command was a major command of the United States Air Force, responsible for continental air defense. It was activated in 1968 and disbanded in 1980. Its predecessor, Air Defense Command, was established in 1946, briefly inac ...

as one of a planned deployment of forty-four mobile radar stations to support the permanent ADC Radar network in the United States sited around the perimeter of the country. This deployment was projected to be operational by mid-1952. Funding, constant site changes, construction, and equipment delivery delayed deployment. This site became operational on 1 April 1956 when the 684th Aircraft Control and Warning Squadron was assigned by the

34th Air Division The 34th Air Division (34th AD) is an inactive United States Air Force organization. Its last assignment was with Air Defense Command at Custer Air Force Station, Michigan. It was inactivated on 31 December 1969. History Assigned to Air De ...

to Mount Lemmon AFS. The squadron began operations using AN/MPS-7, AN/MPS-14, and AN/TPS-10D radars at Mount Lemmon in August 1956, and initially the station functioned as an aircraft control and warning station. The AN/TPS-l0D was soon retired. By 1959 an AN/FPS-20 had replaced the AN/MPS-7 search radar. The Ground Air Transmitting Receiving (GATR) Site (R-92) for communications was located at , Normally the GATR site was connected by a pair of buried telephone cables, with a backup connection of dual telephone cables overhead. The Coordinate Data Transmitting Set (CDTS) (AN/FST-2) at the main site converted each radar return into a digital word which was transmitted by the GATR via microwave to the Control Center. During 1961 Mount Lemmon AFS joined the

Semi Automatic Ground Environment The Semi-Automatic Ground Environment (SAGE) was a system of large computers and associated networking equipment that coordinated data from many radar sites and processed it to produce a single unified image of the airspace over a wide area. SA ...

(SAGE) system, feeding data to DC-21 at

Luke AFB Luke Air Force Base is a United States Air Force base in Maricopa County, Arizona, United States., effective 20 December 2007 It is located west of the central business district of Glendale, and west of Phoenix. Luke AFB is a major trainin ...

, Arizona. After joining, the squadron was re-designated as the 684th Radar Squadron (SAGE) on 15 October 1961. The radar squadron provided information 24/7 the SAGE Direction Center where it was analyzed to determine range, direction altitude speed and whether or not aircraft were friendly or hostile. During the following year, an

AN/FPS-6 The AN/FPS-6 Radar was a long-range height finding radar used by the United States Air Force's Air Defense Command. The AN/FPS-6 radar was introduced into service in the late 1950s and served as the principal height-finder radar for the United Stat ...

supplemented the AN/MPS-14 height-finder radar, and the AN/FPS-20 was upgraded to become an AN/FPS-67. On 31 July 1963, the site was redesignated as NORAD ID Z-92. The AN/FPS-6 was removed in 1968. In addition to the main facility, Mount Lemmon operated several

AN/FPS-14 The AN/FPS-14 was a medium-range search Radar used by the United States Air Force Air Defense Command. This medium-range search radar was designed and built by Bendix as a SAGE system gap-filler radar to provide low-altitude coverage. Operating i ...

Gap Filler sites: * Sells, AZ (M-92A): * Benson, AZ (M-92C): * Globe, AZ (M-92D): The 684th was inactivated in December 1969. However, the GATR facility (R-92) was later reactivated, and is still in use as site G-29 by the 355th Communications Squadron, Davis-Monthan AFB, Arizona. After its closure, Mount Lemmon AFS was used by the

University of Arizona The University of Arizona (Arizona, U of A, UArizona, or UA) is a Public university, public Land-grant university, land-grant research university in Tucson, Arizona. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first ...

and others as an observatory. Its tracking radar (now removed) was used by US Army from

Fort Huachuca Fort Huachuca is a United States Army installation, established on 3 March 1877 as Camp Huachuca. The garrison is now under the command of the United States Army Installation Management Command. It is in Cochise County in southeast Arizona, ap ...

Air Force units and assignments

Units

* 684th Aircraft Control and Radar Squadron'' (Assigned on 1 April 1956) : Activated at

Geiger Field Spokane International Airport is a commercial airport located approximately west-southwest of downtown Spokane, Washington, United States. It is the primary airport serving the Inland Northwest, which consists of 30 counties and includes are ...

, Washington on 1 December 1953 : Moved to

Kirtland AFB Kirtland Air Force Base is a United States Air Force base located in the southeast quadrant of the Albuquerque, New Mexico urban area, adjacent to the Albuquerque International Sunport. The base was named for the early Army aviator Col. Ro ...

, New Mexico on 1 January 1954 : Moved to Davis Monthan AFB, Arizona on 1 April 1954 : Redesignated 684th Radar Squadron (SAGE), 15 October 1961 : Inactivated on 31 December 1969

Assignments

, 1 April 1956 * Los Angeles Air Defense Sector, 1 January 1960 *

Phoenix Air Defense Sector The Phoenix Air Defense Sector (PhADS) is an inactive United States Air Force organization. Its last assignment was with the Air Defense Command 28th Air Division, being stationed at Luke Air Force Base, Arizona. It was inactivated on 1 Apri ...

, 1 May 1961 *

27th Air Division The 27th Air Division was a United States Air Force numbered air division and the geographic Air Defense Command region controlled by the 27th AD. Its last assignment was with Air Defense Command (ADC)'s Tenth Air Force, at Luke Air Force Base, ...

, 1 April 1966-31 December 1969

References

* Cornett, Lloyd H. and Johnson, Mildred W.,
A Handbook of Aerospace Defense Organization 1946 - 1980
', Office of History, Aerospace Defense Center, Peterson AFB, CO (1980). * Winkler, David F. & Webster, Julie L.,
Searching the Skies
', The Legacy of the United States Cold War Defense Radar Program, US Army Construction Engineering Research Laboratories, Champaign, IL (1997).
Information for Mount Lemmon AFS, AZ
{{Aerospace Defense Command, state=collapsed Installations of the United States Air Force in Arizona Semi-Automatic Ground Environment sites Aerospace Defense Command military installations 1956 establishments in Arizona 1969 disestablishments in Arizona Military installations established in 1956 Military installations closed in 1969

History

Air Force units and assignments

Units

Assignments

See also

References