CIM-10 Bomarc

CIM-10 Bomarc
Name	CIM-10 Bomarc
Caption	A CIM-10B on display at the National Museum of the United States Air Force.
Type	Surface-to-air missile
Origin	United States
Used by	United States Air Force, Royal Canadian Air Force
Manufacturer	Boeing
Production date	1959–1964
Service	1959–1972
Engine	Marquardt RJ43-MA-3 ramjet (sustainer), Aerojet liquid-fueled rocket booster
Weight	15,500 lb (7,030 kg)
Length	45 ft 1 in (13.7 m)
Diameter	35 in (890 mm)
Wingspan	18 ft 2 in (5.54 m)
Speed	Mach 2.8
Vehicle range	440 mi (710 km)
Ceiling	100,000 ft (30,000 m)
Guidance	Semi-active radar homing
Launch platform	Fixed launch site

CIM-10 Bomarc. The Boeing CIM-10 Bomarc was a groundbreaking, long-range surface-to-air missile (SAM) developed during the early Cold War to defend North America from high-altitude Soviet bomber aircraft. As the world's first long-range, ramjet-powered anti-aircraft missile and the only SAM ever deployed by the United States Air Force, it represented a key component of the automated SAGE air defense network. Its deployment with both the United States Air Force and the Royal Canadian Air Force marked a significant chapter in continental defense strategy before being rendered obsolete by the intercontinental ballistic missile threat.

Development and Design

The Bomarc program originated from a 1946 United States Army Air Forces requirement, with the name derived from its co-developers, Boeing and the University of Michigan Aeronautical Research Center. The missile's revolutionary design utilized a Marquardt ramjet for sustained cruise at speeds over Mach 2.5, launched vertically by a large, jettisonable Aerojet liquid-fueled rocket booster. Guidance was provided by the Semi-active radar homing system, where ground-based radars like those at SAGE sites would illuminate the target, and the missile's seeker would home in on the reflected energy. The airframe was largely constructed from aluminum and magnesium, with small canard foreplanes and large main wings for aerodynamic control during its flight profile.

Operational History

Declared operational in 1959, the Bomarc was integrated into the SAGE system, which could automatically direct missiles against targets identified by distant radar stations like the DEW Line. The weapon system was designed to engage formations of enemy bombers, such as the Tu-95 Bear, well before they could reach their targets in the continental United States. However, its operational service was relatively brief and controversial; a 1960 accident at a McGuire Air Force Base site involving a nuclear-armed Bomarc raised significant safety concerns. The shift in Soviet threat from bombers to ICBMs, exemplified by developments like the R-7 Semyorka, rapidly diminished the Bomarc's strategic value, leading to its phase-out by 1972.

Variants

Two main production variants were fielded. The IM-99A (later CIM-10A) was the initial model, equipped with a Westinghouse AN/DPN-34 radar seeker and armed with a conventional high-explosive warhead. The vastly improved IM-99B (CIM-10B) featured a more powerful Thiokol solid-fuel rocket booster, a superior Westinghouse AN/DPN-53 seeker, and most significantly, a W40 nuclear warhead with a yield of 7-10 kilotons, allowing it to destroy entire bomber formations with a near miss. Test and prototype versions included the XF-99, XF-99A, and YF-99B designations during the development phase.

Specifications (CIM-10B)

* **Length:** 45 ft 1 in (13.7 m) * **Wingspan:** 18 ft 2 in (5.54 m) * **Diameter:** 35 in (890 mm) * **Launch Weight:** 15,500 lb (7,030 kg) * **Propulsion:** Thiokol solid-fuel rocket booster; Marquardt RJ43-MA-7 ramjet sustainer * **Speed:** Mach 2.8 * **Range:** 440 mi (710 km) * **Ceiling:** 100,000 ft (30,000 m) * **Guidance:** Command guidance mid-course; Semi-active radar homing terminal * **Warhead:** W40 nuclear (7-10 kt)

Deployment and Bases

The United States Air Force deployed Bomarc squadrons at eight permanent sites within the United States, primarily along the eastern and western seaboards and in the Great Lakes region, including locations at McGuire Air Force Base, Niagara Falls Air Reserve Station, and Langley Air Force Base. In a landmark example of binational defense, two squadrons of nuclear-armed CIM-10B missiles were operated by the Royal Canadian Air Force at sites in North Bay, Ontario and La Macaza, Quebec, under the control of the NORAD agreement. The missiles were stored horizontally in hardened shelters and raised to a vertical position for launch.

Legacy and Survivors

The Bomarc remains a historically significant artifact of Cold War technology and the evolution of air defense. Its development pioneered technologies in ramjet propulsion and integrated, automated air defense networks that influenced later systems. Several intact missiles are preserved in museums across North America, including prominent displays at the National Museum of the United States Air Force at Wright-Patterson Air Force Base, the National Air and Space Museum's Steven F. Udvar-Hazy Center, the Air Force Space & Missile Museum at Cape Canaveral Space Force Station, and the Canada Aviation and Space Museum in Ottawa.

Category:Surface-to-air missiles of the United States Category:Cold War anti-aircraft weapons of the United States Category:Boeing missiles