Mount Lemmon Air Force Station

Mount Lemmon Air Force Station
Part of Air Defense Command (ADC)
Type	Air Force Station
Coordinates	32°26′30″N 110°47′22″W / 32.44167°N 110.78944°W / 32.44167; -110.78944 (Mount Lemmon AFS M-92)
Built	1956
In use	1956-1969
Controlled by	United States Air Force
Garrison	684th Aircraft Control and Warning Squadron

Mount Lemmon AFS

Location of Mount Lemmon AFS, Arizona

Map of all coordinates from Google Map of all coordinates from Bing
Export all coordinates as KML
Export all coordinates as GeoRSS
Map of all microformatted coordinates
Place data as RDF

Emblem of the 684th Radar Squadron

Mount Lemmon Air Force Station (ADC ID: M-92, NORAD ID: Z-92) is a closed United States Air Force General Surveillance Radar station. It is located 17.2 miles (27.7 km) north-northeast of Tucson, Arizona. It was closed in 1969.

History

Mount Lemmon Air Force Station was established in 1954 by Air Defense Command 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 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 32°26′23″N 110°47′11″W / 32.43972°N 110.78639°W / 32.43972; -110.78639 (Mount Lemmon AS GATR), 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 (SAGE) system, feeding data to DC-21 at Luke AFB, 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 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 Gap Filler sites:

• Sells, AZ (M-92A): 32°06′44″N 112°04′29″W / 32.11222°N 112.07472°W / 32.11222; -112.07472 (M-92A)
• Benson, AZ (M-92C): 31°59′00″N 110°12′03″W / 31.9833333°N 110.20083°W / 31.9833333; -110.20083 (M-92C)
• Globe, AZ (M-92D): 33°39′36″N 110°33′40″W / 33.66°N 110.56111°W / 33.66; -110.56111 (M-92D)

The 684th was deactivated 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 and others as an observatory. Its tracking radar (now removed) was used by US Army from Fort Huachuca.

Air Force units and assignments

Units:

• 684th Aircraft Control and Radar Squadron, Assigned on 1 April 1956

Activated by 4702d Defense Wing, Geiger Field, Washington on 1 December 1953

Reassigned to 34th Air Division, Kirtland AFB, New Mexico on 1 January 1954

Moved to Davis Monthan AFB, 1 April 1954

Re-designated 684th Radar Squadron (SAGE), 15 October 1961

Inactivated on 31 December 1969

Assignments:

• 34th Air Division, 1 April 1956
• Los Angeles Air Defense Sector, 1 January 1960
• Phoenix Air Defense Sector, 1 May 1961
• 27th Air Division, 1 April 1966-31 December 1969

See also

• List of USAF Aerospace Defense Command General Surveillance Radar Stations

References

	United States Air Force portal
	Military of the United States portal

 This article incorporates public domain material from websites or documents of the Air Force Historical Research Agency.

• A Handbook of Aerospace Defense Organization 1946 - 1980, by Lloyd H. Cornett and Mildred W. Johnson, Office of History, Aerospace Defense Center, Peterson Air Force Base, Colorado
• Winkler, David F. (1997), Searching the skies: the legacy of the United States Cold War defense radar program. Prepared for United States Air Force Headquarters Air Combat Command.
• Information for Mount Lemmon AFS, AZ

External links