M117 bomb

M117 bomb. The M117 is an air-dropped general-purpose bomb developed by the United States in the 1950s. It saw extensive combat use during the Vietnam War and has been deployed by multiple allied air forces. The weapon is known for its reliability and has been integrated on numerous aircraft platforms over its long service life.

Design and development

The development of the M117 stemmed from a United States Air Force requirement for a modern, medium-weight general-purpose bomb following the Korean War. Engineers at the Air Force Armament Directorate sought to create a weapon with improved aerodynamics and fragmentation characteristics compared to earlier World War II-era designs like the M65 bomb. The final design featured a welded steel casing and could be fitted with a variety of nose fuze and tail fuze assemblies, such as the FMU-54 or mechanical M904 fuze, allowing for airburst or impact detonation. Primary explosive fillings included Tritonal and H6, with some naval variants using Minol. Its design allowed for carriage on multiple hardpoints and compatibility with various bomb rack systems, including the Multiple Ejector Rack.

Operational history

The M117 entered service with the United States Air Force and the United States Navy in the late 1950s. Its first major combat deployment occurred during the Vietnam War, where it became a ubiquitous weapon used in countless air interdiction and close air support missions. Aircraft like the B-52 Stratofortress, F-105 Thunderchief, F-4 Phantom II, and A-1 Skyraider routinely carried multiple M117s on strikes against targets along the Ho Chi Minh Trail and during operations like Rolling Thunder and Linebacker II. The bomb was also supplied to allied nations, including the Republic of Vietnam Air Force. Later, it saw use during the Gulf War, deployed by aircraft like the F-111 Aardvark and B-52 Stratofortress against Iraqi forces. Its service continued into the 21st century in limited roles.

Variants

Several variants of the M117 were produced to enhance its capabilities. The M117R was a retarded version equipped with a ballute or parachute retarder, such as the BSU-49, for low-altitude delivery, allowing the attacking aircraft time to escape the blast. The M117D was a dedicated demolition variant with a thicker casing. Training versions included the inert M117E2 practice bomb. Furthermore, numerous improvised guidance kits were later developed, converting the bomb into a precision-guided munition; these included the USAF's Paveway laser-guided bomb kits, which created the GBU-12 Paveway II. Some naval variants were designated with different filling and fuzing options for specific missions.

Specifications

The M117 is nominally a 750-pound class weapon, though its actual weight varies with filling and fuzing. Typical weight is approximately 820 pounds. The bomb body is about 88 inches in length and 16 inches in diameter. The standard explosive filling is 386 pounds of Tritonal, though other compositions like H6 were also used. The casing is constructed from forged steel. The bomb utilizes a standard 14-inch suspension lug spacing for attachment to MIL-STD bomb racks. Its lethal radius against personnel is significant due to its fragmentation pattern, which was optimized through testing at facilities like Eglin Air Force Base.

Deployment and use

Deployment of the M117 required integration with a wide array of United States and allied aircraft. Standard delivery modes included level, dive, and toss bombing, with release parameters calculated by the aircraft's bombing system. In Vietnam, tactics evolved to include large-scale carpet bombing by formations of B-52 Stratofortress aircraft from Strategic Air Command. The bomb was also used in close air support roles by forward air controllers directing flights of A-37 Dragonfly or O-2 Skymaster. Logistics and handling were managed through the US Air Force's and US Navy's conventional munitions supply chains, with storage at major bases like Clark Air Base and Anderson Air Force Base. While largely superseded by newer JDAM and Paveway series weapons, remaining stocks have been used in training exercises and were employed during the War in Afghanistan.

Category:General-purpose bombs of the United States Category:Vietnam War weapons of the United States Category:Aerial bombs of the Cold War