AGM-136 Tacit Rainbow

The missiles would fly in advance of crewed aircraft up to 450 km to pre-programmed target zones and patrol there until enemy radar sources were detected which would then be destroyed, acting as a loitering munition. This extended patrol time on target ("loiter time") was the key feature of the new system, a persistent anti-radiation missile (PARM) as opposed to a HARM. This would allow for the threatening suppressive effects that HARMs have for significantly longer times, allowing friendly aircraft to operate in the area with a higher degree of safety for a longer time. The project was started by the DoD in 1982, but moved to the control of the USAF Aeronautical Systems Division in 1984 as a joint Navy/Air Force project. The majority of the system was designed and developed by Northrop with Texas Instruments providing the seek head and Boeing providing a system that allowed it to be launched from B-52 bombers. The first test air-launch was on July 30, 1984. The unit was 8 ft long and 5 ft in span with a body diameter of 27 in, flight and control surfaces deployed after launch. It weighed around 431 lb including the 40 lb warhead. Power was provided by a Williams F121 turbofan, producing 310 N of thrust from the, unit. Some sources state that production units would have used a 1200 N variant of the Williams International WR-24. While achieved speed and range are uncertain, low subsonic speed flight was probable and all sources indicate a range much lower than the hoped-for 450 km. Each unit was to cost around $200,000, up to thirty would have been loaded in a single B-52. The Naval Research Advisory Committee reported in 1989 that the project was not progressing well. In 1991 a DoD audit found numerous management problems. The program was canceled in 1991 (FY 1992), without any production units and at a total cost of around $4 billion. It was only the second post-Vietnam military project to be canceled after completing testing but before production.

• Name — AGM-136A • Origin — United States • Type — Anti-radiation missile • Design Date — 1982 to 1991 • Designer — Northrop, Texas Instruments and Boeing • Weight — 431 lb

• Illustration — An AGM-136 Tacit Rainbow on display at the Frontiers of Flight Museum Below is a list of museums which have a Tacit Rainbow in their collection: • Museum of Aviation, Robins Air Force Base, Georgia • National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio • U.S. Naval Museum of Armament & Technology, NAWS China Lake, California