Westinghouse AN/GPA-35 Ground Environment

The Westinghouse AN/GPA-35 Ground Environment (GPA-35 colloq.) was a United States Air Force surface-to-air missile weapons direction system. It was used for launch and steering during CIM-10 Bomarc tests during the Cold War. The command guidance system manufactured by Westinghouse Electric Corporation used Bendix AN/FPS-20 Radar data to track the missile. Lincoln Laboratory Division 6 had an AN/GPA-35 Study Group for integrating the AN/GPA-35 into the SAGE System. Notable launches with GPA-35 guidance included:


 * 1956 October — Six launches were used to test the AN/GPA-35 capability to command BOMARC intercept of QB-17 drones.
 * 1957 October — A BOMARC test with "live high-explosive warhead" failed when the GPA-35 commanded "faulty mid-course guidance".
 * 1958 May 1 - The "GPA-35 could not control the missile beyond 130 miles."
 * 1958 August 7 - A GPA-35 took control of an airborne BOMARC from the Experimental SAGE Sector, and the missile malfunctioned and crashed into the Atlantic Ocean.
 * 1959 March 6 - A straying BOMARC was self-destructed near the western boundary of the Eglin Gulf Test Range after a GPA-35 had transmitted the wrong commands.
 * 1959 April 13 — The GPA-35 lost control of the missile 100 seconds after launch.
 * 1959 April 24 — GPA-35 control was used for simultaneous guidance of two BOMARCS.