TINKER HISTORY: Douglas IM-99 BOMARC missile

The Bomarc was a surface-launched, pilotless interceptor missile designed to destroy enemy aircraft. (U.S. Air Force photo)

The Bomarc was a surface-launched, pilotless interceptor missile designed to destroy enemy aircraft. (U.S. Air Force photo)

TINKER AIR FORCE BASE, Okla. --

The Boeing/Michigan Aeronautical Research Center IM-99A/B BOMARC missile was the world’s first ground-based long-range, anti-aircraft missile and the only anti-aircraft missile ever operated by the U.S. Air Force. The missile was supersonic capable and equipped with a 7-10 kiloton nuclear warhead. The missile’s name is a combination of the manufacturer and the research center that helped in the initial research project, thus BOMARC.

Few historical documents are available which show or discuss the work done at Tinker on the IM-99. The Oklahoma City Air Materiel Area was responsible for the missile from May 1955 to June 1957 when it was undergoing significant test and evaluation. The lack of details is most likely due to the classified nature of the program in the early years. There are notes and a write-up about the missile being managed and maintained here, but little else. It still remains a significant milestone for the advancement of U.S. Air Force technology and air power overall. 

The IM-99 was designed to counter the Soviet Union’s increasing threat from long-range bombers capable of flying across the northern pole to strike Canada and the U.S. in the late 1940s and early 1950s.  Development and testing progressed rapidly building on missile technology of the time and resulted in missiles of increasing accuracy, range and utility. The key features of the IM-99A, later designated CIM-10A, was initial take-off from a vertical position using a liquid-fueled rocket-booster to propel it until it accelerated to supersonic speeds. After reaching supersonic speeds the two fuselage-slung Marquardt ramjets would ignite and propel the missile as it was guided toward the targets by ground-based controllers. Once the missile was within 10 miles of its target, its onboard Westinghouse AN/DPN-34 radar would guide it toward intercept. The missile would detonate, “at the closest point of pass or on impact,” according to Boeing’s fact sheet. Detonation within a few miles of the target was considered a successful intercept because the resulting nuclear blast and shockwaves would destroy the airborne bombers.

Improvements later incorporated into the design were a switch from the dangerous and unstable liquid rocket fuel which has to be loaded aboard the missile to a solid rocket fuel booster of lighter weight. This lower weight and stability not only increased the overall range of the IM-99Bs, but also dramatically increased the response time from launch order to firing by up to 30 minutes. The BOMARC was incorporated into the North American Aerospace Defense Command network and used by Canada as well.

As the stand-off between the Soviet Union and the U.S. dragged on into the Cold War, changes in strategy toward intercontinental ballistic missiles targeted at each other’s major cities and bases ensured mutually assured destruction. The chance of heavy bombers coming over the poles lessened and the IM-99A/B became less valuable to the overall mission. However, after being withdrawn from its intercept mission many continued on as CQM-10A/B high-speed target drones for tests of other air-defense missiles. Many of these Air Force missiles helped refine the U.S. Army’s Air-Defense mission as targets for the Raytheon MIM-23 HAWK missile system and the success the program enjoyed in cementing the Army’s capability and motto: If it flies, it dies. The last of the BOMARC drones were retired in 1972.