Boeing CH-47 Chinook

Summary

Description

During late 1956, the United States Department of the Army sought to replace the piston-engine-powered Sikorsky CH-37 Mojave with a new, gas turbine-powered helicopter. In 1957, Vertol began work on a new tandem-rotor helicopter, designated as the Vertol Model 107 or V-107. In September 1958, a joint Army–Air Force board recommended procuring the Vertol-built medium transport helicopter. In June 1958, the U.S. Army awarded Vertol a contract for a small number of the rotorcraft, giving it the YHC-1A designation, with a capacity to carry 20 troops. Considered too heavy for the assault role and too light for transport, the Army decided to procure a heavier transport helicopter and upgrade the UH-1 "Huey" for tactical troop transport. The YHC-1A was improved and adopted by the Marines as the CH-46 Sea Knight in 1962. The Army then ordered an enlarged derivative of the V-107, known internally as the Model 114, designated HC-1B. On 21 September 1961, the preproduction Boeing Vertol YCH-1B made its initial hovering flight, and in 1962, the HC-1B was redesignated the CH-47A under the 1962 United States Tri-Service aircraft designation system; it was also named "Chinook".

The Chinook possesses several means of loading various cargoes, including multiple doors across the fuselage, a wide loading ramp located at the rear of the fuselage, and a total of three external ventral cargo hooks to carry underslung loads. Upon its introduction to service in 1962, the helicopter was considerably faster than contemporary 1960s utility helicopters and attack helicopters. Capable of a top speed of 170 knots (200 mph; 310 km/h), it remains one of the faster helicopters in the US inventory. The CH-47 is powered by two turboshaft engines, mounted on each side of the helicopter's rear pylon and connected to the rotors by drive shafts. The counter-rotating rotors eliminate the need for an antitorque vertical rotor, allowing all power to be used for lift and thrust. The ability to adjust lift in either rotor makes it less sensitive to changes in the center of gravity, important for cargo lifting and dropping. Improved versions, such as the CH-47D, included upgraded engines, composite rotor blades, a redesigned cockpit to reduce workload, improved and redundant electrical systems and avionics, and an advanced flight control system. The latest generation, the CH-47F, features major upgrades to reduce maintenance, digitized flight controls, and two 4,733-horsepower (3,529 kW) Honeywell engines.

The armament of the CH-47 Chinook varies depending on the specific variant and operational requirements. Generally, it can be equipped with up to three pintle-mounted medium machine guns, typically 7.62 mm M240/FN MAG machine guns, positioned at the loading ramp and shoulder windows for self-defense. Additionally, the CH-47 can be armed with the 7.62 mm M134 Minigun rotary machine gun for increased firepower. The ACH-47A variant, an armed/armored version, featured a more extensive array of weapons, including 20 mm cannons, 40 mm grenade launchers, .50-caliber machine guns, and rocket launchers or minigun pods. Beyond these internal defensive weapons, the Chinook's primary strength lies in its payload capacity, able to carry 33–55 troops or 24 stretchers with 3 attendants, or a cargo load of up to 24,000 lb (10,886 kg).

The CH-47 has seen extensive operational use across various theaters and conflicts. During the Vietnam War, the U.S. Army utilized the Chinook for artillery placement in mountainous terrain, resupply missions, and casualty evacuation, with the aircraft often armed with M60 machine guns for self-defense. The Army had 21 Chinook companies in Vietnam at the war's peak. Some Chinooks were converted into ACH-47As, armored gunships providing heavy fire support, though these were ultimately withdrawn due to high maintenance costs and demand for transport roles. In the 1970s and 1980s, Iranian CH-47s saw action against Kurdish rebels and during the Iran-Iraq War, performing crucial troop deployments and artillery support despite facing losses from enemy fire. During the Falklands War in 1982, Argentina and the United Kingdom deployed Chinooks, with British Chinooks performing remarkably, despite losses due to enemy attacks. More recently, the CH-47D has been heavily involved in Operation Enduring Freedom in Afghanistan and Operation Iraqi Freedom, transporting troops, supplies, and serving as a casualty evacuation platform. Its lift capacity was particularly valuable in the Afghan mountains, though it has also been subject to hostile fire. Disasters, peacekeeping missions, and other secondary missions such as medical evacuation, disaster relief, search and rescue, fire fighting, and heavy construction assistance also contributed to the Chinook's lengthy history. The military version of the helicopter has been exported to nations across the world; the U.S. Army and the Royal Air Force have been its two largest users.

Main Variants:

• CH-47A: The initial production model, powered by Lycoming T55 engines, served as an all-weather, medium-lift helicopter with a maximum gross weight of 33,000 lb.

• ACH-47A: Known as "Guns A Go-Go", this variant was converted into a gunship with heavy armament, including machine guns, cannons, and grenade launchers, for testing in Vietnam.

• CH-47B: An interim upgrade featuring more powerful engines, redesigned rotor blades, and strakes for improved flying characteristics, with the capability to mount door and ramp-mounted machine guns.

• CH-47C: This version featured more powerful engines and transmissions and served widely during the Vietnam War, eventually replacing the older Piasecki H-21 Shawnee in the combat assault support role.

• CH-47D: Sharing the same airframe as earlier models, the CH-47D featured more powerful engines, a triple-hook cargo system, advanced avionics, and a Global Positioning System and was introduced into service in 1979.

Technical specifications

Current operating countries

Country		Units
	United States	513 (+30)
	Japan	82
	United Kingdom	57 (+14)
	South Korea	43
	Iran	40
	United Arab Emirates	28
	Greece	25
	Italy	22
	Singapore	20 (+11)
	Egypt	19 (+23)
	India	15
	Australia	14
	Canada	14
	Turkey	11
	Netherlands	10 (+3)
	Spain	8 (+13)
	Taiwan	8
	Morocco	3
	Libya	2
	Germany	0 (+60)
	Saudi Arabia	0 (+48)

Numbers in parentheses, e.g. '(+5)', indicate units ordered but not yet delivered.

All operators

United Arab Emirates • Argentina • Australia • Canada • Germany • Egypt • Spain • United Kingdom • Greece • India • Iran • Italy • Japan • South Korea • Libya • Morocco • Netherlands • Saudi Arabia • Singapore • Thailand • Turkey • Taiwan • United States

Photo of CH-47 Chinook

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