Stephenville Air Station

Stephenville Air Station (ADC ID: N-23, C-23) is a closed General Surveillance Radar station. It is located 5.9 mi west-northwest of Stephenville, Newfoundland and Labrador. It was closed in 1971.

History
The site was established in 1951 as a General Surveillance Radar station, funded by the United States Air Force, one of the many that would make up the Pinetree Line of Ground-Control Intercept (GCI) radar sites.

It was activated by the Northeast Air Command which stationed the Federalized Air National Guard 105th Aircraft Control and Warning Squadron at Stephenville Air Station on 19 January 1952. It operated the following radars:
 * Search Radars: AN/CPS-5C, AN/FPS-502, AN/FPS-20A, AN/FPS-93A
 * Height Radars: AN/MPN-4, AN/TPS-502, AN/FPS-6B, AN/FPS-90

As a GCI base, the 105th's role was to guide interceptor aircraft toward unidentified intruders picked up on the unit's radar scopes. These interceptors were assigned to the 64th Air Division at Goose AFB, Labrador. On 1 August 1953, the Air National Guard squadron was released from active service, and the unit was replaced by the 640th Aircraft Control and Warning Squadron, which assumed its personnel and equipment. The station was given designation "N-23" (later "C-23").

The station was re-assigned to the USAF Air Defense Command on 1 April 1957. In 1963, the site was connected to the Semi Automatic Ground Environment (SAGE) Direction Center (DC-31) at Goose AFB, and the site was upgraded to an AN/FPS-93A, AN/FPS-90 and AN/FPS-6B radars.

On 30 June 1971, the USAF transferred control of the site to the Canadian Forces. It was inactivated and has stood vacant ever since.

USAF units and assignments
Units:
 * Activated as the 105th Aircraft Control and Warning Squadron at Newark Municipal Airport, New Jersey, by December 1950.
 * Federalized in August 1951 and moved to Otis AFB, Massachusetts
 * Moved to Grenier AFB, New Hampshire on 1 September 1951
 * Moved to Stephenville Air Station on 19 January 1952
 * Inactivated and returned to Air National Guard control on 1 August 1953


 * Activated as the 640th Aircraft Control and Warning Squadron Stephenville Air Station 1 August 1953
 * Inactivated 30 June 1971

Assignments:
 * 64th Air Division (NEAC), 1 September 1951
 * 4731st Air Defense Group (ADC), 1 November 1957
 * Goose Air Defense Sector, 6 June 1960
 * 37th Air Division, 1 April 1966
 * 21st Air Division, 31 March 1970-30 June 1971