M75 grenade launcher
Encyclopedia
The M75 is a 40mm automatic grenade launcher
that was used primarily as an aircraft weapon in United States service and was one of the first weapons to use the high velocity 40x53mm grenade.
Corporation (later referred to in this time period as Ford Aerospace). While 40mm low velocity grenades were being developed for infantry use, the M75 was to be an aircraft weapon using a higher velocity grenade for additional range. While an aircraft gun pod
designated the XM13 was developed for it, it would see far greater use as a helicopter weapon, mainly during the Vietnam War
. The most notable systems the M75 was part of were the M5 used on the UH-1 Iroquois
and the turreted M28 system used on the AH-1 Cobra
. In the last case the weapon was quickly replaced by the improved M129
launcher.
, and being trialed as a door gun for the UH-1 series with the XM94 system. Operation of the weapon is extremely similar to that of the M75, with the reciprocating barrel and cam assembly still presenting itself, and the weapon still being electrically driven.
Grenade launcher
A grenade launcher or grenade discharger is a weapon that launches a grenade with more accuracy, higher velocity, and to greater distances than a soldier could throw it by hand....
that was used primarily as an aircraft weapon in United States service and was one of the first weapons to use the high velocity 40x53mm grenade.
Overview
Development of the M75 began in the late 1950s by the Philco-FordFord Aerospace
Ford Aerospace & Communications Corp. was the aerospace and defense business of Ford Motor Company. It consisted of the Space Systems Division and the Western Development Labs .Partial company timeline:*1956 Aeronutronic becomes Ford Motor Company division.*1961 Ford Motor Company...
Corporation (later referred to in this time period as Ford Aerospace). While 40mm low velocity grenades were being developed for infantry use, the M75 was to be an aircraft weapon using a higher velocity grenade for additional range. While an aircraft gun pod
Gun pod
A gun pod is a detachable pod or pack containing machine guns or automatic cannon and ancillaries, mounted externally on a vehicle such as a military aircraft which may or may not also have its own guns....
designated the XM13 was developed for it, it would see far greater use as a helicopter weapon, mainly during the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
. The most notable systems the M75 was part of were the M5 used on the UH-1 Iroquois
UH-1 Iroquois
The Bell UH-1 Iroquois is a military helicopter powered by a single, turboshaft engine, with a two-bladed main rotor and tail rotor. The helicopter was developed by Bell Helicopter to meet the United States Army's requirement for a medical evacuation and utility helicopter in 1952, and first flew...
and the turreted M28 system used on the AH-1 Cobra
AH-1 Cobra
The Bell AH-1 Cobra is a two-bladed, single engine attack helicopter manufactured by Bell Helicopter. It shares a common engine, transmission and rotor system with the older UH-1 Iroquois...
. In the last case the weapon was quickly replaced by the improved M129
M129 grenade launcher
The M129 is a 40mm automatic grenade launcher that was used as an aircraft weapon in United States service. It was developed from the earlier M75 and was capable of using both the high-velocity 40x53mm grenade and the lower velocity 40x46mm grenade....
launcher.
Design
The weapon is described as an "air-cooled, electrically powered, rapid firing weapon." All portions of the firing cycle are powered this way so the unit requires an external power source. Other important features are the reciprocating barrel and cam assembly that drive the other components of the system.. All phases of the weapon cycle are positively controlled by the drum cam assembly in which a planetary gear train is enclosed, responsible for reducing the motor's high speed to the desired rate for the gun. The 5/8 horsepower 28 Volts DC motor is mounted on the turret bracket and drives the drum cam trough a flexible shaft in order to isolate it from the weapon's recoil. The weapon accepts linked ammunition, which was fed from rotary drums in the case of the M5 and M28 systems, and from boxes in the case of the XM9 systems. The M5 could also use a box magazine.Derivative
While the M75 had no variants, Philco-Ford developed an improved derivative, the M129, which quickly supplanted the M75. The M129 was effectively a redesign of the older weapon to incorporate a concentric cam and improved mount, as well as a higher rate of fire of 400 rpm. The major problem with the M75 was the torque created due to the barrel being below the operating drum. In the M129 the barrel is concentric with the drum and the excessive torque is thus eliminated. The M129 was used in the XM8 and the aforementioned M28 helicopter armament systems, as well as, the XM51 for the ill-fated AH-56 CheyenneAH-56 Cheyenne
The Lockheed AH-56 Cheyenne was a single-engine attack helicopter developed by Lockheed for the United States Army's Advanced Aerial Fire Support System program to produce the Army's first dedicated attack helicopter...
, and being trialed as a door gun for the UH-1 series with the XM94 system. Operation of the weapon is extremely similar to that of the M75, with the reciprocating barrel and cam assembly still presenting itself, and the weapon still being electrically driven.
Sources
- Gervasi, Tom. Arsenal of Democracy III: America's War Machine, the Pursuit of Global Dominance. New York, NY: Grove Press, Inc, 1984. ISBN 0-394-54102-2.
- Gunston, Bill. The Illustrated Encyclopedia of Aircraft Armament. New York, NY: Orion Books, 1988. ISBN 0-517-56607-9.
- United States. Headquarters, Department of the Army. FM 1-40 Attack Helicopter Gunnery. Washington, DC: Headquarters, Department of the Army, 1969.
See also
- List of grenade launchers
- List of crew-served weapons of the U.S. Armed Forces
- Mk 19 grenade launcherMk 19 grenade launcherThe Mk 19 Grenade Launcher is a 40 mm belt-fed automatic grenade launcher or grenade machine gun that entered U.S. military service during the Cold War, first seeing action during the Vietnam War and remaining in service today.-Overview:...
- M129 grenade launcherM129 grenade launcherThe M129 is a 40mm automatic grenade launcher that was used as an aircraft weapon in United States service. It was developed from the earlier M75 and was capable of using both the high-velocity 40x53mm grenade and the lower velocity 40x46mm grenade....
- United States 40 mm grenades
- U.S. aircraft gun podsU.S. aircraft gun podsThe idea of the gun pod as a concept largely came into its prime during and period following World War II. So-called "package gun" installations on US medium and light bombers, such as the B-25 Mitchell and A-26 Invader, were probably the first such attempts by the United States military...
- U.S. Helicopter Armament SubsystemsU.S. Helicopter Armament SubsystemsThe United States military has developed a number of Helicopter Armament Subsystems since the early 1960s. These systems are used for offensive and defensive purposes and make use of a wide variety of weapon types including, but not limited to machine guns, grenade launchers, autocannon, and rockets...