The M197 electric cannon is a 20 mm three-barreled electric Gatling-type

rotary cannon A rotary cannon, rotary autocannon, rotary gun or Gatling cannon, is any large-caliber multiple-barreled automatic firearm that uses a Gatling-type rotating barrel assembly to deliver a sustained saturational direct fire at much greater rate ...

used by the

United States military The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is the ...

Development

The M197 electric cannon was developed primarily for use by

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

gunship A gunship is a military aircraft armed with heavy aircraft guns, primarily intended for attacking ground targets either as airstrike or as close air support. In modern usage the term "gunship" refers to fixed-wing aircraft having laterally-mo ...

s. Development began in

1967 Events January * January 1 – Canada begins a year-long celebration of the 100th anniversary of Confederation, featuring the Expo 67 World's Fair. * January 5 ** Spain and Romania sign an agreement in Paris, establishing full consular and ...

after experience in the

Vietnam War The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...

revealed the inadequacy of the 7.62 mm

Minigun The M134 Minigun is an American 7.62×51mm NATO six-barrel rotary machine gun with a high rate of fire (2,000 to 6,000 rounds per minute). It features a Gatling-style rotating barrel assembly with an external power source, normally an electric ...

for gunship use. The M197 is essentially a lightened version of the General Electric M61 Vulcan cannon, with three

barrels A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, u ...

instead of six. Its maximum

rate of fire Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. This can be influenced by several factors, including operator training level, mechanical limitations, ammunition availability, and weapon condition. In m ...

is one quarter that of the Vulcan, largely to limit its

recoil Recoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force requ ...

for light aircraft and helicopter use. It shares the Vulcan's M50 and PGU series 20 mm

ammunition Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other weap ...

History

The M197 went into service on later marks of the

AH-1 Cobra The Bell AH-1 Cobra is a single-engined attack helicopter developed and manufactured by the American rotorcraft manufacturer Bell Helicopter. A member of the prolific Huey family, the AH-1 is also referred to as the HueyCobra or Snake. The A ...

, using either the M97 or A/A49E-7 armament subsystems, and was also fitted in a ventral

turret Turret may refer to: * Turret (architecture), a small tower that projects above the wall of a building * Gun turret, a mechanism of a projectile-firing weapon * Objective turret, an indexable holder of multiple lenses in an optical microscope * Mi ...

on the U.S. Marine Corps YOV-10D Bronco NOGS. It is also the basis of the GPU-2/A

gun pod A gun pod is a detachable pod or pack containing machine guns, autocannons, revolver cannons, or rotary cannons and ancillaries, mounted externally on a vehicle such as a military aircraft which may or may not also have its own guns. Description ...

, which incorporates the cannon, a

battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...

and electric drive

motor An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gen ...

, and 300 rounds of linkless ammunition. In the Cobra, the weapon is supplied with a

magazine A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...

of 700 linked rounds, with a total capacity including feeder system of 750 rounds. It has a cyclic rate of fire of 730+-50 rounds per minute. Standard practice is to fire the cannon in 30- to 50-round bursts. With extended automatic firing from a hover, the recoil is sufficient that the application of forward cyclic to maintain one's position over the ground is inadequate. The M197 remains in use in the latest AH-1W Cobra and AH-1Z Viper gunships. Although the weapon's rotary drive is theoretically quite reliable, its ammunition feed has been anything but: Marine pilots initially reported an alarmingly high jam rate (sometimes greater than 30%). The USMC and the manufacturer are aware of the problem and in 2011 a linkless feed system developed by Meggit Defense Systems was incorporated into the AH-1W and the Zulus. The system is capable of holding 650 +/-3 rounds in the storage unit with approximately 40 rounds in the feed chute. The M197 is also mounted as a chin turret in Italy's

Agusta A129 Mangusta The Agusta A129 Mangusta ( en, Mongoose) is an attack helicopter originally designed and produced by Italian company Agusta. It is the first attack helicopter to be designed and produced wholly in Europe. It has continued to be developed by Ag ...

CBT helicopter, with a capacity of 500 rounds. The

XM301 The XM301 Cannon was an externally powered, three-barrel 20 mm rotary cannon made by General Dynamics for the United States Army. Developed for use with the RAH-66 Comanche stealth helicopter, it is the world's lightest 20 mm rotary cannon ...

was an improved M197 intended to be the gun on the later canceled RAH-66 Comanche. The weapon's current contractor is General Dynamics Armament Systems.

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

has claimed downing one Iraqi

MiG-21 The Mikoyan-Gurevich MiG-21 (russian: Микоян и Гуревич МиГ-21; NATO reporting name: Fishbed) is a supersonic jet fighter and interceptor aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. Its nickna ...

fighter on 14 February 1986 during the

Iran–Iraq War The Iran–Iraq War was an armed conflict between Iran and Iraq that lasted from September 1980 to August 1988. It began with the Iraqi invasion of Iran and lasted for almost eight years, until the acceptance of United Nations Security Council ...

using the M197 gun turret installed on its

AH-1J International The Bell AH-1 SuperCobra is a twin-engined attack helicopter that was developed on behalf of, and primarily operated by, the United States Marine Corps (USMC). The twin Cobra family, itself part of the larger Huey family, includes the AH-1J Se ...

s. The cannon was also used during the "

dogfight A dogfight, or dog fight, is an aerial battle between fighter aircraft conducted at close range. Dogfighting first occurred in Mexico in 1913, shortly after the invention of the airplane. Until at least 1992, it was a component in every majo ...

s" between Iranian AH-1Js and Iraqi helicopters (usually

Mi-24 The Mil Mi-24 (russian: Миль Ми-24; NATO reporting name: Hind) is a large helicopter gunship, attack helicopter and low-capacity troop transport with room for eight passengers. It is produced by Mil Moscow Helicopter Plant and has been o ...

s and

Gazelle A gazelle is one of many antelope species in the genus ''Gazella'' . This article also deals with the seven species included in two further genera, ''Eudorcas'' and ''Nanger'', which were formerly considered subgenera of ''Gazella''. A third f ...

s).

Ammunition

References

; Notes ; Online
GlobalSecurity.org M197

{{DEFAULTSORT:M197 Gatling Gun 20 mm artillery Aircraft guns Multi-barrel machine guns Rotary cannon United States Marine Corps equipment Military equipment introduced in the 1960s

Development

History

Ammunition

See also

References