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GPA-37 Course Directing Group - A Weapons Directing Analog Computer system built by General Electric Corporation, Heavy Military Electronic Equipment Department at Syracuse in conjunction with Air Research and Development Command Rome Air Development Center and the Electronics Research Laboratories of Columbia University. The first GPA-37 Radar Course Directing Equipment was installed at the Verona Test Site on 13 Dec 1955. The first operational data link test flight took place on an F-86D fighter interceptor aircraft on 28 Dec 1955.

GPA-23 Course Directing Console of the GPA-37.

GPA-37s were established at ten Air Force long-range radar sites in the late 1950s to automate the manual Ground Control Intercept (GCI) mission against Soviet Manned Bomber attacks with the U.S. Army NIKE Missile Master System. Additional systems were established at Keesler Air Force Base for maintenance training and at Tyndall Air Force Base for Weapons Controller Training. An additional sixteen sites were identified to provide a backup to SAGE direction centers.
The GPA-37 had three major component groups:

GPA-37 Major Component Groups
Nomenclature Name Function
GPA-23 Computing-Tracking Group The main component of this group is the GPA-23 Weapons Control Console and associated equipment cabinet which allows a single controller to manage six intercepts on a single console.
GPA-34 Converter Group Controls the interface between the GPA-23 and the GKA-1.
GKA-1 Flight Control Group Provides automatic data and voice communications between the site and F-102A and F-106 supersonic interceptors.

With all three major groups, the weapons controller could direct the interceptor aircraft directly to the target with computer commands (Automatic Intercept) or voice commands (Manual Intercept).

Post SAGE Implementation

The implementation of the SAGE system brought fears that the loss of one or two Direction Centers could open up wide expanses of the country to attack and a number of Radar stations were selected to receive the GPA-37s as a backup system. From the Jan-Jun 1961 NORAD/CONAD History:

"When work on a plan for emergency backup to SAGE was begun in mid-1960, NORAD asked USAF ADC to put a freeze order on the scheduled release of GPA-37's to the ground stations. This manual control equipment would be needed in the expanded Mode III operation:
Following the November 1960 meeting of NORAD region and headquarters officers on the backup plan, NORAD trimmed its requirement to 16 stations, thus enabling GEEIA to begin removal of GPA-37's where they were not needed. At the same time, NORAD asked that GPA-37's be re-installed in two stations. Additional guidance was provided the regions in early 1961 on the retaining of plotting boards, air-ground transceivers, and other manual equipment.
In May 1961, USAF ADC recommended that the GPA-37 program be reduced to GPA-23's. NORAD's initial reaction was to disagree and to insist that the original program now incorporated in the 10 April Manual Backup Plan be adhered to. However, subsequent strong assurance by ADC that the GPA-23 proposal would afford equal operational capability at considerably less expense, changed NORAD's point of view. On 29 June, NORAD concurred in the substitution of the GPA- 23's for the GPA-37's."

GPA-37 Partial Site List (edit list)
No Site State Unit ID Function From To GPS Notes
1 Fort Lawton AFS WA 635th RP-01 NCC-MM 1960 1960 47.6575,
2 Gibbsboro AFS NJ 772nd RP-63 NCC-MM 39.82417,
3 Fort Heath RS MA 820th MM-1 NCC-MM 42.38889,
4 Arlington Heights AFS IL 755th RP-31 NCC-MM 42.06431,
Originally at Williams Bay
5 San Pedro Hill AFS CA 670th RP-39 NCC-MM 33.74611,
6 Oakdale AFS PA 662nd RP-62 NCC-MM 40.39722,
7 Fort Meade RS MD 770th RP-54 NCC-MM 39.11634,
8 Highlands AFS NJ 646th P-09 NCC-MM 40.39139,
Installed before 1 Jul 1958
9 Lockport AFS NY 763st P-21 NCC-MM 43.14028,
Installed before 1 Jul 1958
10 Selfridge AFB MI 661st P-20 NCC-MM 42.62694,
Installed before 1 Jul 1958
11 Othello AFS WA 637th P-40 1959 1960 46.72139,
John Stanton 1959-1960
12 Tyndall AFB FL 678th TM-189 Training 30.07603,
Weapons Director Training Set
Wayne Setzer 1958-1959
13 Thule AFB GL 931st G-32 76.40296,
14 Saratoga Springs NY 656th P-50 43.01139,
Richard Ryan 1958-1959
Arthur D Sampson 1958
Jim Mackin 1958-1961
James A. Engelmann 1958-1961
15 Fortuna AFS ND 780th P-27 48.90389,
16 Lac St. Denis QC 11 AC&W C-2 1957-11 45.9375,
Site History
17 Dauphin Island AL 693rd TM-196 30.25028,
Pete J. O'Brien Sep 1958-Jun 1960
18 Texas Tower 2 MA 762nd
TT-2 41.75,
19 Murphy Dome AFS AK 744th F-02 NCC-MM
1960 1961 64.95194,
Levi B. Norman Jr
GPA-23 Console at Murphy Dome
20 Keesler AFB MS Training 30.40574,
Maintenance Training Set
John Stanton 1959
Course ATS 30372-10 AN/GPA-37 14 weeks
21 Jacksonville NAS RS FL 679th M-114 30.22861,
Gary Heath
22 North Charleston SC 962nd M-113 1961 1964? 32.89556,
Charles Jones
23 Lake Charles LA 812th TM-194 1960 30.18417,
AIC Robert J.W. Powles
24 Rockport TX 813th TN-191 1959 1963 28.09167,
A2C Leslie Nicholson 1-7/1963
AIC Harold G Seaman 12/1959-9/1961
Picture in paper May 1959
25 Naselle WA 759th P-57 1958 1959 46.42194,

* NCC-MM Indicates a GPA-37 within a NORAD Control Center co-located with U.S. Army Missile Master Center (NIKE).
* Name in notes indicates person who worked on GPA-37 on this site.
GPA-37 Course Directing Weapons Directing
Element Value Notes
Nomenclature GPA-37
Manufacturer General Electric Corporation, Heavy Military Electronic Equipment Department
Type Course Directing
Number Made
Introduced 1955
GPA-23 Console, Capable of Controlling Six Intercepts.

GPA-37 Components (edit list)
Component Model Quantity Height Width Deep Weight Notes
Computing Tracking Group GPA-23
Converter Group GPA-34
Flight Control Group GKA-1

See Also:


  • 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
  • MIL-HDBK-162A, 15 Dec 1965.
  • Jan-Jun 1961 NORAD/CONAD History Pdf
  • Forty Years of Research and Development at Griffiss Air Force Base Pdf, page 28.


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