The Lockheed F-94 was the United States Air Force's first operational jet-powered all-weather interceptor aircraft.
Built to a 1948 USAF specification for a radar equipped interceptor to replace the aging Northrop F-61 Black Widow and North American F-82 Twin Mustang, and specifically designed to counter the threat of the USSR's new Tupolev Tu-4 bombers, the F-94 was derived from the TF-80C (later T-33) two-seat trainer version of the F-80 Shooting Star, with guns, radar, and automatic fire control system added.
The fire control system was the Hughes E-1, which incorporated an AN/APG-33 radar (derived from the AN/APG-3 which directed the Convair B-36's tail guns) and a Sperry A-1C computing gunsight. The TF-80C fuselage was lengthened to hold the electronics and radar. Since the conversion seemed so simple, a contract was awarded to Lockheed in early 1949, with the first flight on 16 April 1949.