Armed helicopter

From Wikipedia, the free encyclopedia

A CH-54 Tarhe of the US Army 1st Cavalry Division carrying a BLU-82/B bomb
A CH-54 Tarhe of the US Army 1st Cavalry Division carrying a BLU-82/B bomb

An armed helicopter is a military helicopter armed for attacking targets on the ground, and sometimes in the air. Basic transport helicopters, intended to deliver combat troops to an objective, are armed principally for self-defense. It is the subset of attack helicopters that carry heavy armament such as autocannon and machine-gun fire, rockets, and precision guided missiles such as the Hellfire. Many attack helicopters are also capable of carrying air to air missiles, though mostly for purposes of self-defense.

Today's attack helicopter has two main roles: first, to provide direct and accurate close air support for ground troops, and the second, in the anti tank role to destroy enemy armor concentrations. Attack helicopters are also used to supplement lighter helicopters in the armed scout role. Scout helicopters may use laser designators or other equipment to provide guidance to the heavier weapons fired from the attack helicopters. In some special operations missions, a large helicopter with extensive electronics may navigate for a formation of lighter armed helicopters.

Specialized armed helicopters fly from ships at sea, and are equipped, variously, for antisubmarine warfare or strikes with anti-shipping missiles. These helicopters may help guide weapons fired from a cooperating ship or fixed-wing aircraft.

Contents

[edit] History

Weapons fire delivered by helicopter began informally in the Korean War, and evolved through the Algerian and early Vietnam Wars, in the form of armed helicopters: general-purpose military helicopters that were modified to carry various weapons. In the Vietnam War, the first purpose-built attack helicopter, in the form of the AH-1 Cobra appeared, intended for close air support. After Vietnam, and especially into the 1990s, US Army, and some Soviet, attack helicopters became more and more optimized for the antitank mission.[1] The US Marine Corps continued to see the helicopter, as well as its fixed-wing aviation assets, in the close support role, although the Marines did dedicate a close-support helicopter in the form of the AH-1 Cobra and AH-1 Super Cobra. Soviet helicopters, however, retained troop transport capability than being attack-only.

[edit] Algerian War

Hiller YH-32 Hornet in the Museum of Flight Seattle display is considered the first attack helicopter.
Hiller YH-32 Hornet in the Museum of Flight Seattle display is considered the first attack helicopter.

After the Korean War, a few farsighted military establishments began to examine the helicopter as a possible platform for use in ground attack. The French Army was one of the first military forces to modify and use helicopters in combat in a ground attack role during the Algerian War of 1954-62. In 1955, French field commanders placed infantry machine gunners in the stretcher panniers of their Bell 47 (Sioux H-13) casualty evacuation helicopters. The ad hoc gunships were used to reach FLN guerrilla positions on otherwise inaccessible mountain ridges and peaks, but were far too underpowered.[1]

In 1956, the French Air Force experimented with arming the Sikorsky Sikorsky S-55, then being superseded in service by the more capable Piasecki H-21 and Sikorsky CH-34 helicopters. The H-19 was originally fitted with two rocket launchers, and a 20-mm cannon, both mounted axially on the outside of the aircraft. Then, a 20-mm cannon, two 12.7-mm machine guns, and a 7.5-mm light machine gun were mounted to be fired from the cabin windows,[2] but this load proved far too heavy, and even more lightly-armed H-19 gunships proved underpowered. Some Piasecki H-21 helicopters were armed with fixed, forward-firing rockets and machine guns and a few even had racks for bombs, but the H-21 lacked the maneuverability and performance needed for offensive action. Most H-21s in service were eventually fitted with a door-mounted 12.7- or 20-mm gun for self-defense only.

The Sikorsky H-34 was also modified into a gunship by the French Navy: standard armament comprised an MG 151 20-mm cannon firing from the cabin door, two 12.7-mm machine guns firing from the cabin windows to port, plus racks for 37 mm or 68 mm rockets. While the CH-34 was effective in the ground attack role, official evaluations at the time indicated that the CH-21 was more likely to survive multiple hits by ground fire than was the CH-34; this was assumed to be a consequence of the location and construction of the CH-34's fuel tanks. Nevertheless, by the close of the Algerian War, attack helicopters such as the CH-34 were being used in synchronized operations with troop-carrying CH-21 helicopters in large-scale counterinsurgency operations.

[edit] U.S. Army

The United States Army began to employ helicopters built by Bell, Hiller, Sikorsky and Piasecki. At first, helicopters were used mainly as airborne ambulances, cargo carriers, and observation platforms, or as a rescue craft for picking up pilots downed in the sea or from otherwise inaccessible terrain. However, the U.S. and the United Kingdom soon began modifying existing helicopters as anti-submarine weapons (ASW) platforms, carrying depth bombs and Magnetic Anomaly Detector gear. After learning of French Army experiments, there was a movement in the U.S. Army to arm helicopters. Under the leadership of Colonel Jay Vanderpool, the U.S. Army modified Sikorsky and other larger helicopters with fixed and flexible-mount machine guns, rockets, and cannon. While Col. Vanderpool was ridiculed for his efforts, some in the army saw his efforts as a great aid to ground troops. At the time the army leadership felt that the U.S. Air Force was not doing enough to support ground forces.[3] Due to the Key West Agreement, the Army could not field its own ground attack fixed-wing aircraft.

[edit] Vietnam and the Gunship

During the 1950s, with the increasing use of the helicopter for infantry transport, the U.S. saw a need for helicopters to be used as aerial artillery to provide fire suppression and ground support close to the battle. The first United States use of the attack helicopter in large-scale combat operations was during Vietnam. The U.S. Army took a UH-1 'Huey' and put machine guns and 2.75 in Folding Fin Aerial Rockets (FFAR) on struts parallel with the fuselage. With its more powerful turbine engine, the UH-1C Huey gunship configuration worked well, and saw considerable combat service in Vietnam.

In the mid-1960s the U.S. Army concluded that a purpose-built gunship with more speed and firepower was required in the face of increasingly intense ground fire (often using heavy machine guns and anti-tank rockets) from Viet Cong and NVA troops. Based on this realization, and with the growing involvement in Vietnam, the U.S. Army developed the requirements for a dedicated attack helicopter, the Advanced Aerial Fire Support System (AAFSS). The aircraft would be able to hover-out-of-ground effect (OGE) at 6000 feet (PA) and 95 degrees, with a 220 knot speed dash capability and carry a much larger payload of weapons. The aircraft design selected for this program in 1965, was Lockheed's AH-56 Cheyenne.[4]

Cheyenne prototype
Cheyenne prototype

However, the U.S. Army split its efforts between the acquisition of a dedicated attack helicopter, and the continued use of improvised interim aircraft (such as the UH-1B/C). So, that same year, a group of high-level officers met to evaluate several prototype versions of armed aircraft to determine which provided the most significant increase in capability to the UH-1B. The three highest-ranking aircraft out of the evaluation (Sikorsky S-61, Kaman UH-2, and Bell Huey Cobra) were selected to compete in flight trials conducted by the Aviation Test Activity. As a result, Bell's Huey Cobra was recommended to be the interim armed helicopter until the Cheyenne was fielded. On 13 April 1966, the U.S. Army awarded Bell Helicopter Company a production contract for 110 AH-1G Cobras.[4] The Cobra had a slender fuselage to make the aircraft a smaller target, increased armor protection, and greater speed.

Current Huey-Cobra
Current Huey-Cobra

In 1967, the first AH-1Gs were deployed to Vietnam, around the same time that the Cheyenne successfully completed its first flight and initial flight evaluations. And while the Cheyenne program suffered setbacks over the next few years due to design issues (a result of discrepancies in requirement documents during the contract process), the Cobra was establishing itself as an effective aerial weapons platform, even despite its performance shortcomings when compared to the AH-56[4] and design issues of its own. By 1972, when the Cheyenne program was eventually cancelled to make way for the Advanced Attack Helicopter (AAH)[4], the interim "Snake" had built a solid reputation as an attack helicopter.

[edit] Soviet Army

During the 1960s, the Soviet Union, seeing the same need for a ground-attack helicopter, equipped Mil Mi-8's in a similar configuration as the US Army's UH-1s. This attack helicopter was eventually developed into the Mi-24 Hind; these helicopters saw extensive action in Afghanistan during the eighties. MI-24s were also exported in large numbers to many Asian and African countries. Russian attack helicopters developed in nineties include the Mi-28 Havoc and KA-50/52.

[edit] Helicopters used for bombing

The idea of the helicopter as a bomber has likely been around since helicopters first came into military service. The helicopter offers what might appear to be a highly stable bombing platform, making the idea all the more attractive. The idea is generally used by air forces conducting counterinsurgencies, and often by those lacking traditional fixed wing options.

[edit] Helicopter bombing in Vietnam

Likely the first organized usage of a helicopter as a tactical bomber, the United States Army employed the UH-1 Iroquois, CH-47 Chinook, and CH-54 Tarhe helicopters. The US Army had already conducted tests using the OH-13 Sioux fitted with small napalm tanks.[5]

The CH-47 was used most often to assist in the clearing of bunkers, using an improvised bomb made from 55-gallon drums of bulk CS powder, designated Bomb, Fuze, and Burster, CS in 55-gallon Drum, XM920.[6] Thirty of these bombs, containing eighty pounds of CS powder, could be carried by a CH-47, and were used to "saturate base camps, way stations, or infiltration routes to deny their use."[7]

The US Army used the UH-1 with a far wider array of systems. Using the M156 Universal Mount, conventional aircraft dispensers for cluster munitions and mines were fitted.[8] Another system developed was the Mortar Aerial Delivery System or MADS. This system used standard 60mm or 81mm mortar rounds in dispensers mounted on the side of the aircraft, and was to be used against both preplanned targets and targets of opportunity.[9] Pictures show this system in use as late as 1969.[10] Even improvised bombs, made from things such as a "can of engine oil...[and] a thermite grenade" or "four or five concussion grenades...[with] belted M-60 ammunition around the grenades" were used.[11]

The US Army also conducted a number of drops of large bombs using the CH-54 helicopter for the purposes of clearing landing zones. Operational drops were conducted using both modified M121 10,000 lb bombs and the BLU-82/B 15,000 lb bomb.[12] Tests conducted prior to the deployment of weapons and equipment for Operation Combat Trap led to discontinued use of the CH-54 and a switch to the C-130E(I) aircraft (later MC-130E).[13]

Both the US Army and US Marine Corps also investigated using the AH-1 Cobra as a bomber. The Army tested a dispenser system that could be used to drop smoke grenades, while the USMC went further and qualified the aircraft to carry the CBU-55/A Fuel Air Explosive.[14] While the USMC continued to qualify their subsequent AH-1 variants for the CBU-55/A weapon, there are no reports of it actually being used in combat.

[edit] Helicopter bombing in El Salvador

El Salvador during their conflict with FMLN and other guerrillas between 1980 and 1992, made use of UH-1 Iroquois in the bombing role. UH-1Hs and UH-1Ms flew punitive strikes against villages linked to the FLN dropping 250 and 500 pound bombs. The need for this greater flexibility was required by the nature of the conflict and the lack of resources available to the Salvadoran Air Force. Since the bombs utilized used the same type of mounting hardware as the standard rocket launchers, the FAS used M156 universal mounts and essentially unmodified aircraft.[15]

[edit] Helicopter bombing in Lebanon

Helicopter bombing was used by the Lebanese Army during the 2007 Siege of Nahr al-Bared. The Lebanese Army technical teams converted UH-1H utility helicopters into bombers due to the urgent need to fight the Fatah al-Islam terrorist group. They mounted 30-year-old 400 lb (250 kg) Mk.82 bombs, originally used on Hawker Hunter attack aircraft. This was accomplished by modifying the UH-1H helicopters, raising the height of the landing skids and installing belly mounted bomb-release gear and pylons from retired Mirage III jets.[16]

The helicopters dropped 250-kilogram and 400-kilogram bombs from altitudes between 3,000 and 4,000 feet. The pilots used GPS devices to help guide them from point of departure to the bomb-release point. The strikes demolished many of the camp’s two- and three-floor buildings and many of the fortifications of Fatah Al-Islam, according to LAF officials.[17]

Fawzi Abu-Farhat, a retired LAF brigadier general and editor of the monthly Arab Defense Journal, said, "This is the first time in the history of warfare that a helicopter is used as a bomber ... in an effective manner." Abu-Farhat's assertion is not correct as helicopters have been used in the same role and with good success in previous conflicts. He went on to stress that "such helicopter bombs can only be used in special cases, when the enemy does not have air defenses and when the weather conditions are good.[18]

[edit] Tests and evaluations

Other nations have also made moves toward helicopter bombing, but have not put it into practice. The Soviet Union qualified both the Mil Mi-8 and Mil Mi-24 to use members of the FAB general purpose bomb family. It is possible these aircraft may have been put into service in this role by the armed forces of Sudan and Sri Lanka.[19]

The Philippines also tested a single Sikorsky H-34 as an attack helicopter, armed with both rockets and bombs on locally fabricated racks. This aircraft appears to have been the extent of the testing, and the Philippines did not introduce any H-34s in this capacity.[20]

[edit] See also

[edit] References

  1. ^ Mazarella, Mark N (1994). "Adequacy of U.S. Army Attack Helicopter Doctrine to Support the Scope of Attack Helicopter Operations in a Multi-Polar World" (PDF). . U.S. Army Command and General Staff College Retrieved on 2007-12-12.
  2. ^ Tom Cooper (12 Nov 2003). Algerian War 1954-1962. Western and North African Database. Air Combat Information Group (www.acig.org).
  3. ^ Dwayne A. Day (28 Feb 2003). Assault Helicopters. Centennial of Flight Commission (www.centennialofflight.gov).
  4. ^ a b c d Office of the Assistant Vice Chief of Staff of the Army (1973). "An Abridged History of the Army Attack Helicopter Program". . Department of the Army
  5. ^ Mutza, 1995. p. 29
  6. ^ United States, 1969. p. K-2
  7. ^ Rottman, 2006. p. 46
  8. ^ United States, 1969. p. B-3, K-2
  9. ^ United States, 1967. p. 12-3
  10. ^ Drendel, 1983. p. 51
  11. ^ Drendel, 1974. p. 20
  12. ^ Mesko, 1984. p. 48
  13. ^ United States, 1970. p. 1-3
  14. ^ Mutza, 2002. p. 10-1, 34
  15. ^ Cooper, Tom. Air Combat Information Group. 1 September 2003 El Salvador, 1980-1992. Access Date: 3 September 2007
  16. ^ Kahwaji, Riad. Ya Libnan. 3 September 2007 The victory - Lebanon developed helicopter bombers. Access Date: 3 September 2007
  17. ^ Kahwaji, Riad. Ya Libnan. 3 September 2007 The victory - Lebanon developed helicopter bombers. Access Date: 3 September 2007
  18. ^ Kahwaji, Riad. Ya Libnan. 3 September 2007 The victory - Lebanon developed helicopter bombers. Access Date: 3 September 2007
  19. ^ Cooper, Tom. Air Combat Information Group. 29 October 2003 Sri Lanka, since 1971. Access Date: 3 September 2007
  20. ^ Lundh, 1998. p. 100
  • Drendel, Lou. Gunslingers in Action. Carrollton, TX: Squadron/Signal Publications, Inc, 1974. ISBN 0-89747-013-3.
  • Drendel, Lou. Huey. Carrollton, TX: Squadron/Signal Publications, Inc, 1983. ISBN 0-89747-145-8.
  • Lundh, Lennart. Sikorsky H-34: An Illustrated History. Atglen, PA: Shiffer Military/Aviation History, 1998. ISBN0-7643-0522-0
  • Mesko, Jim. Airmobile: The Helicopter War in Vietnam. Carrollton, TX: Squadron/Signal Publications, Inc, 1984. ISBN 0-89747-159-8.
  • Mutza, Wayne. H-13 Sioux Mini In Action. Carrollton, TX: Squadron/Signal Publications, Inc, 1995. ISBN 0-89747-329-0.
  • Mutza, Wayne. Walk Around: AH-1 Cobra. Carrollton, TX: Squadron/Signal Publications, Inc, 2002. ISBN 0-89747-438-4.
  • Rottman, Gordon. Viet Cong and NVA Tunnels and Fortifications of the Vietnam War. Oxford, UK: Osprey Publishing, 2006. ISBN 1-84603-003.
  • United States. Headquarters, Department of the Army. FM 1-40 Attack Helicopter Gunnery. Washington, DC: Headquarters, Department of the Army, 1969.
  • United States. Headquarters, Department of the Army. FM 1-100 Army Aviation Utilization. Washington, DC: Headquarters, Department of the Army, 1967.
  • United States. Headquarters, Pacific Air Force, Directorate, Tactical Evaluation, CHECO Division. Commando Vault. Headquarters, Pacific Air Force, Directorate, Tactical Evaluation, CHECO Division, 1970.

[edit] External links