Cross City Air Force Station

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Cross City Air Force Station (1958-1970) - A Cold War U.S. Air Force Radar Station established in 1958. Located near Cross City, Dixie County, Florida. Initially assigned a Permanent ID of M-114, a Sage ID of Z-114 and later a JSS ID of J-10. Closed in 1970.

Cross City Air Force Station in the 1960s.


Established in 1959 and became operational in 1959 as Cross City Air Force Station manned by the 691st Radar Squadron (SAGE).

Initial equipment included the FPS-20A search radar and two FPS-6A height-finder radars. This configuration (a SAGE qualified long range search radar and two SAGE qualified height-finders) met the requirements for transition to SAGE System operation.

SAGE System Transition

The transition of the manual GCI system to the automated SAGE system began with the installation of the FST-2 coordinate data transmitter and search radar upgrades. The FST-2 equipment digitized the radar returns and transmitted the digital returns to the SAGE direction center. Under the SAGE System, interceptor aircraft were directed to their targets by the direction center computers and controllers, greatly reducing the need for local controllers and equipment at every radar station.

The FST-2 was a very large digital system using vacuum tube technology. Over 6900 vacuum tubes were used in each FST-2 requiring 21 air-conditioned cabinets, 40 tons of air conditioning, 43.5 kva of prime power, and usually a large new addition to the operations building. The FST-2B modification added two more cabinets but with newer solid-state (transistor) technology to process coded responses from aircraft transponders.

SAGE System Operation

Former Gunter SAGE Direction Center DC-09
Cross City SAGE Direction Centers & Sectors
Assigned Direction Center Sector
1 Nov 1959 - 1 Apr 1966 Gunter SAGE Direction Center DC-09 Montgomery Air Defense Sector
1 Apr 1966 - 14 Nov 1969 Gunter SAGE Direction Center DC-09 32nd Air division
14 Nov 1969 - 19 Nov 1969 Fort Lee SAGE Direction Center DC-04 33nd Air division
19 Nov 1969 - 30 Sep 1970 Fort Lee SAGE Direction Center DC-04 20th Air division

The site began operation as a SAGE site in 1960 initially feeding the Gunter SAGE Direction Center DC-09. On 1 Oct 1959 the squadron designation was changed from the 691st AC&W Squadron to 691st Radar Squadron (SAGE) indicating the new SAGE System role.

In 1962 the search radar was upgraded to an FPS-66, and finally to a FPS-66A in 1967. One FPS-6A was removed in 1969.

With the closure of Gunter SAGE Direction Center DC-09 in 1969, control of Cross City AFS was switched to the Fort Lee SAGE Direction Center DC-04 in Virginia.


Cross City AFS and the 691st were deactivated on 30 Sep 1970.

Gap Fillers

Cross City AFS was responsible for the maintenance of two remote unattended gap-filler radar sites. The unattended gap filler sites were placed in locations where the main search radar lacked coverage. These sites were equipped with short range FPS-14 or FPS-18 search radars and FST-1 Coordinate Data transmitters that sent digitized radar target data to a SAGE direction center and to the main radar site. Both the radar set and the FST-1 were dual channel to increase site up time. Maintenance teams were dispatched for regularly scheduled maintenance or when fault indicators on the FSW-1 remote monitoring equipment suggested the site had problems. The FSW-1 also allowed remote operation of specific functions such as channel changes for the radar and for the FST-1, it also allowed remote operation of the diesel generators at the gap filler site. The Cross City AFS gap-filler radars were located at Bridgeboro GA and Perry, FL.

Cross City AFS Gap Filler Radar Sites (edit list)
ADC NORAD Location State Type From To GPS Notes
M-114A Z-114A Perry FL FPS-18, FST-1 1961-04 1970-06-05 30.07816,
Building exists
Tower exists
M-114B Z-114B Bridgeboro GA FPS-18, FST-1 1959-11 1970-06=05 31.42545,
Building exists
Tower exists

Cross City AFS Major Equipment List
Search Radar HF Radar Data Systems Radio
Unit Designations
  • 691st Aircraft Control & Warning (AC&W) Squadron (1958-1959)
  • 691st Radar Squadron (SAGE) (1959-1970)* 691st Radar Squadron (1960-1970)
691st Assignments

Current Status

Now Cross City Correctional Center, some structures remain. No public access.

Location: Cross City in Dixie County, Florida.

Maps & Images

Lat: 29.63461 Long: -83.09886

See Also:


  • Cornett, Lloyd H. & Johnson, Mildred W., A Handbook of Aerospace Defense Organization (1946-1980), Office of History ADC, Peterson AFB, Colorado, 31 Dec 1980, 179 pages, Pdf, page 161.
  • Winkler, David F., Searching the Skies: the Legacy of the United States Cold War Defense Radar Program, USAF Hq Air Combat Command, 1997, 192 pages, Pdf, page 108-109.
  • USGS Geographic Names Information System (GNIS) Database Entry: 2087477


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