Point Arena Air Force Station
Point Arena Air Force Station (1951-1998) - A Cold War Air Force Radar Station first established in 1951 near Point Arena, Mendocino County, California. Named Point Arena Air Force Station after the location. Initially assigned a Permanent ID of P-37, later a Sage ID of Z-37 and a JSS ID of J-34. Abandoned in 1998.
Established in 1951 and became operational December 1951 as Point Arena Air Force Station manned by the 776th AC&W Squadron. The station initially had both a Ground-Control Intercept (GCI) and early warning misssion. The early warning mission involved tracking and identifing 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.
Initial equipment included one FPS-3 search radar and one FPS-4 height finder radar. In 1955 a FPS-8 search radar was installed and later upgraded to become a GPS-3. One FPS-20 search radar and one FPS-6 height finder replaced the original sets in 1958. A FPS-6B height finder was added 1960, completing the basic configuration needed for SAGE System operation, one long range search radar and two long range height finder radars.
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
The 776th Radar Squadron was deactivated in 1980 but elements of the 26th Air Defense Squadron continued operations at the site. In 1980 the military scope operators were replaced with civil service personel. In 1986 the last military personel left the site, leaving 40-50 civilians manning a operational USAF installation with no military members assigned. In 1987 the site came under the Southwest Air Defense Sector of the 25th Air Division. The site surveillance mission was assumed by the FAA/USAF JSS Rainbow Ridge FAA Radar Site, J-83A, equipped with an ARSR-4 radar.
The final retreat ceremony for Point Arena AFS was held on 30 Sep 1998 by members of the 9th Communications Squadron from Beale Air Force Base. Photos indicated that the site was operated at closure by OL A 9th Communications Squadron (ACC).
Point Arena AFS was responsible for the maintenance of one remote unattended gap filler radar site. 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 Point Arena AFS gap filler radar was located at Laytonville, California.
The physical plant of the site was divided into a 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 27 unit housing area for married personnel.
A separate radio site housed the radio equipment for directing aircraft intercepts. Like most early radar stations, Point Arena originally had a separate radio transmitter and receiver sites used by local controllers for voice direction of fighter interceptors to their targets. With the SAGE System, the SAGE Direction centers had the primary task of directing intercepts and the local radio sites were reconfigured, usually into a single site that was known as the Ground to Air Transmitter Receiver (GATR) site. The GATR site communicated with the interceptors from either the local site or the SAGE direction center via voice commands and/or a digital data link.
Still a USAF facility under caretaker status as of 2013. Some buildings, two radar towers, the operations buildings and GATR site remain in place.