Manassas Air Force Station

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Manassas Air Force Station (1952-1965) - A Cold War Air Force Radar Station first established in 1952 as Quantico Air Force Station near Manassas, Prince William County, Virginia. Renamed Manassas Air Force Station in July 1957 after the location. Initially assigned a Permanent ID of P-55, later a Sage ID of Z-55. Abandoned in 1965.

Manassas AFS Former Enlisted Barracks.
Manassas AFS Former Radar Operations Building.
Former Manassas AFS Overview, L-R Operations Bldg., FPS-35 Tower, HQ Bldg., and Edge of Barracks.


Established in 1952 and became operational in March 1952 as Quantico Air Force Station manned by the 647th AC&W Squadron. The station initially had both a Ground-Control Intercept (GCI) and early warning mission. The early warning mission involved tracking and identifying all aircraft entering their airspace while the GCI mission involved guiding Air Force interceptors to any identified enemy aircraft. Controllers at the station vectored fighter aircraft at the correct course and speed to intercept enemy aircraft using voice commands via ground-to-air radio. Renamed Manassas Air Force Station in July 1957

Initial equipment included the FPS-3 search radar and a CPS-4 height-finder radar.

SAGE 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

The site began operation as a SAGE System site in January 1959, initially feeding the Fort Lee SAGE Direction Center DC-04. Two FPS-6 (one A model and one B model) height-finder radars were installed in 1958 in preparation for SAGE System operation.

Former Manassas AFS FPS-35 Radar Tower.

The FPS-3 search radar was replaced by an FPS-35 in 1961 but it did not become operational until 1962. The FPS-35 was tested to determine if it could detect missile launchings and it detected Polaris and Minuteman missile launches from Cape Canaveral on 28 Jun 1962. Additional testing indicated that the FPS-35 had marginal value for missile detection. In 1963 the FPS-6B height-finder was replaced with an FPS-26A height-finder.

Gap Fillers

Manassas AFS was responsible for the maintenance of three 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 Manassas AFS gap-filler radars were located at Hermanville, MD; Hanover, PA; and Thomas, WV.

Manassas AFS Gap Filler Radar Sites (edit list)
ADC NORAD Location State Type From To GPS Notes
P-55B Z-55B Hermanville MD FPS-14, FST-1 1957-11 1963-12 38.22805,
Building still exists
P-55D Z-55D Hanover PA FPS-14, FST-1 1957-11 1960-12 39.85784,
Building still exists
P-55F Z-55F Thomas WV FPS-14, FST-1 1958-02 1968-00 39.14772,
Building still exists


Manassas AFS and the 647th were deactivated on 1 Mar 1965. The FPS-35 radar antenna sail was sent to Fortuna Air Force Station, ND to replaced their damaged sail.

Physical Plant

Manassas Air Force Station Plan

Manassas AFS Former Motor Pool Area.

The physical plant of the site was divided into the main site, a cantonment area, a housing area and a radio site. The main site housed the operations buildings, the radar towers, and the backup generators. The cantonment area housed the enlisted barracks, the bachelor officer's quarters, the orderly room, the dining hall, the motor pool and other support buildings. Apart from the main site was a small nine unit housing area for key married personnel. A separate Ground to Air Transmitter/Receiver (GATR) radio site housed the radio equipment for directing aircraft intercepts.

Manassas AFS Major Equipment List
Search Radar HF Radar Data Systems
Unit Designations
  • 647th Aircraft Control & Warning (AC&W) Squadron (1952-1959)
  • 647th Radar Squadron (SAGE) (1959-1965)
647th Assignments
  • 1 Jan 1951 - Assigned at Ft Meade, MD, assigned to the 503rd AC&W Gp.
  • 6 Feb 1952 - Transferred to the 26th AD.
  • Apr 1952 - Moved to permanent site at Quantico, VA.
  • 16 Feb 1953 - Transferred to 4710th Def Wg.
  • 1 Mar 1956 - Transferred to the 85th AD.
  • Summer of 1957 - Site redesignated Manassas AFS, VA.
  • 1 Sep 1958 - Transferred to Washington ADS.
  • 1 Oct 1959 - Redesignated from AC&W Sq to 647th Radar Sq (SAGE).
  • 25 Jun 1965 - Discontinued.

Manassas Air Force Station Partial Commanders List (edit list)
Assumed Relieved Rank Name Cullum Notes
4 Sep 1956 Captain McCullen, Robert J. N/A
4 Sep 1956 Lt. Colonel Colboch, Lloyd E. N/A

Current Status

The main site is now the Administrative and logistics center for the Prince William County School District with many of the former Air Force buildings still standing and in active use. Gone are the FPS-6, FPS-3 and FPS-26 radar towers. The former BOQ building seems to have been incorporated into a much larger school building. The Radar Operations Building seems much larger than the normal operations buildings and may have been expanded in anticipation of BUIC operations that never materialized. The housing area has been leveled but is still fenced.

Location: Manassas in Prince William County, Virginia.

Maps & Images

Lat: 38.62778 Long: -77.43833

  • Multi Maps from ACME
  • Maps from Bing
  • Maps from Google
  • Elevation: 407'

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 156.
  • 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 161.
  • USGS Geographic Names Information System (GNIS) Database Entry: 2089505


  • Bad Links /cgi-bin/museum/acwinfo2x.cgi?site=%22Manassas+AFS,+VA%22&key=ManassasAFSVA&pic=ManassasAFSVA&doc=ManassasAFSVA&www=ManassasAFSVA Manassas Air Force Station]
  • Wikipedia - Manassas Air Force Station
  • Bad Links /museum/parsehtml.php?html=ManassasAFSVAarticle200001.html&type=doc_html Article]

Visited: 2 Jun 2016

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