Stephenville Air Station

 (1952-1971) - A Cold War Pinetree Line Air Force Radar Station first established in 1952 near Stephenville, Newfoundland and Labrador. Originally a part of nearby Harmon Air Force Base, later named Stephenville Air Station on 21 Feb 1956 in accordance with NEAC General Order #14. Initially assigned a Lashup ID of L-23, a permanent ID of N-23 and Later C-23. Abandoned in 1971.

Origns
Constructed between 1951-1953 and became operational in 1952 manned by the 105th AC&W Squadron. The station initially had a Ground-Control Intercept (GCI) mission, an early warning mission and functioned as a temporary Air Defense Direction Center (ADDC). 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. Manned by the 640th AC&W Squadron from 1 Aug 1953 to closure on 1 Oct 1971.

105th AC&W Squadron
The 105th AC&W Squadron of the New Jersey Air National Guard activated on 1 Aug 1951 and that is the date the unit was federalized for 24 months of federal service. The unit was moved to Grenier Air Force Base in September 1951. At Grenier AFB the unit packed their equipment for shipment to Newfoundland and in March 1952 they boarded a Military Ship Transportation Services (MSTS) ship to Harmon Air Force Base, Newfoundland.

The permanent site at Stephenville was not completed when the 105th AC&W arrived so a temporary "Lashup site" L-23 was established on the same mountain top as the permanent site. The temporary site, L-23, housed a CPS-5 search radar, an MPS-4 height-finder and was operational around april 1952.

On 1 Aug 1953 the 105th AC&W Squadron was released from federal duty and returned to the New Jersey Air National Guard.

640th AC&W Squadron
The 640th AC&W Squadron was activated at Stephenville AS on the same date that the 105th was returned to the Air Guard, 1 Aug 1953. They operating the site with an N-22 ID.

The CPS-5 search radar was upgraded to a CPS-6B in January 1954. The CPS-5 was dismantled and turned in to Supply in the first quarter of 1955. A backup search radar, the FPS-502, and a backup height-finder radar, the TPS-502 were also installed.

In 1961 the FPS-20A search radar and FPS-6B height-finder radar were installed, replacing the CPS-6B. The FPS-20A was later modified to become an FPS-93A in 1965. The FPS-6B height-finder radar was upgraded to an FPS-90.

In 1966 Harmon Air Force Base closed. Harmon had been a close support base for the 640th at Stephenville AS since it was established. With all the Air Force Bases in Newfoundland and Labrador closed except for Goose Bay Air Force Base, support became remote support and much more limited. Stephenville AS and the 642nd AC&W were deactivated on 1 Oct 1971.

Physical Plant
The physical plant of the site was divided into the main site, a cantonment area and radio sites. The main site housed the operations buildings, the radar towers, and the backup generators. The cantonment area was adjacent to the main site and housed the enlisted barracks, the bachelor officer's quarters, the orderly room, the dining hall, the motor pool and other support buildings. Separate small Ground to Air Transmitter/Receiver (GATR) radio sites housed the radio equipment for directing aircraft intercepts.

Note: The unit designations and assignments from the ADC Organizational Handbook are probably incorrect since they do not give a deactivation date for the 105th and they don't have the 642nd AC&W activated until 1957.

Current Status
Abandoned near Stephenville, Newfoundland and Labrador.

See Also:
 * Permanent System Radar Sites
 * US Radar Sets
 * Lashup System
 * Pinetree Line

Sources:
 * , page 93, 97.

Links:
 * Radomes - Stephenville Air Station
 * Wikipedia - Stephenville Air Station
 * Pinetree Line - Stephenville
 * Pinetree Line - 1951 – 105th AC&W Squadron