Northrop AGM-136A Tacit Rainbow The Northrop AGM-136A was a jet-powered missile developed in the early 1980s as a way to suppress enemy air defenses. Conceived under the Tacit Rainbow project, the low-cost AGM-136A would be launched in "swarms" from bombers or fighters ahead of the main attacking force. On-board computers guided them independently to a pre-programmed area where they would search for enemy radars. When an AGM-136A detected signals radiating from the enemy's radar transmitter, it would attack. During the Southeast Asia War, the North Vietnamese had defeated radar-seeking missiles by turning their radars off and on to avoid being hit. However, the AGM-136A could not be "fooled" so easily. As long as fuel remained, it could patrol until the radar resumed operations and attack again. Whether it destroyed the radars or just kept them turned off, Tacit Rainbow would suppress the air defenses long enough for the main attack to proceed unthreatened. The first Tacit Rainbow air-launch occurred in July 1984, but the program was cancelled for budget reasons in 1991. The AGM-136A on display was used in airworthiness tests and presented to the Museum in August 1991. TECHNICAL NOTES: Armament: WDU-30/B 40-lb. blast fragmentation warhead Engine: Williams International F-121 turbofan of 70 lbs. thrust Cruising speed: Subsonic Supersonic Range: More than 50 miles Span: 5 ft. 2 in. Length: 8 ft. 4 in. Body diameter: 2 ft. 3 in. Weight: 430 lbs. Click here to return to the Cold War Gallery. Find Out More Related Fact Sheets Williams International F-121 Fanjet Engine Note: The appearance of hyperlinks does not constitute endorsement by the National Museum of the USAF, the U.S. Air Force, or the Department of Defense, of the external website, or the information, products or services contained therein.