CH-47 Chinook

The CH-47 Chinook is a highly versatile, twin engine, twin rotor heavy-lift helicopter. The contra-rotating rotors eliminate the need for a rear vertical rotor, allowing all power to be used for vertical lift and provide a speed of 173 mph (150 knots, 278 km/h). Its primary missions range from troop movements and artillery emplacement to battlefield resupply. Chinooks have been sold to 16 nations, the largest users of which are the US Army and the Royal Air Force, see RAF Chinook. A commercial model of this aircraft, the Boeing 234 Chinook, is used worldwide for logging, construction, fighting forest fires, and supporting petroleum exploration operations.

CH-47A

The Boeing Vertol (model 114) YCH-1B/YCH-47A made its initial hovering flight on September 21, 1961. The all-weather medium lift CH-47A Chinook first entered service in Vietnam about 1966. The CH-47A was powered by either AlliedSignal Engines T55-L-5 2200 shp (1,640 kW) or T55-L-7 2650 shp (1,980 kW) engines.

CH-47B

CH-47B was powered by two AlliedSignal Engines T55-L-7C 2850 shp (2,130 kW) engines. The CH-47B featured a blunted rear rotor pylon, redesigned rotor blades, and strakes along the rear ramp and fuselage to improve flying characteristics. The CH-47B was the standard troop transport used by the 1st Cavalry Division in Vietnam. The Chinook could be equipped with two door mounting M60D 7.62 mm NATO machine guns on the M24 armament subsystem and a ramp mounted M60D using the M41 armament subsystem. A few CH-47A Go-Go Birds were also used experimentally in the gun ship role. Some CH-47 "Bombers" were equipped to roll-out riot control gas or napalm onto Viet Cong bunker complexes from the rear cargo ramp. The CH-47 could be equipped with a hoist and cargo hook. The Chinook proved especially valuable in "Pipe Smoke" aircraft recovery missions. The "Hook" recovered about 12,000 aircraft valued at over $3 billion during the war.

CH-47C

The Boeing Vertol (model 234) CH-47C had a strengthened transmission, AlliedSignal Engines T55-L-11C 3750 shp (2,800 kW) engines, and increased range. The CH-47C could carry from 33 to 44 troops or 24 litters plus two medical attendants. The RAF's Chinook HC.1, introduced in 1980, is comparable to the CH-47C.

All three models saw wide use during the Vietnam war. They replaced the H-21 Shawnee in the combat assault role.

CH-47D

The CH-47D was originally powered by two T55-GA-712 engines. Most D Models are now fitted with two T55-GA-714 engines. Models CH-47A, CH-47B, and CH-47C, all utilized the same airframe, but later models featured upgraded engines. With its triple-hook cargo system, the CH-47D is able to carry heavy payloads -- for example, bulldozers and forty-foot containers -- at speeds over 155 mph (250 km/h). In air assault operations it often serves as the principal mover of the 155 mm M198 howitzer, thirty rounds of ammunition, and an eleven-man crew. Like most US Army helicopters, the Chinook is equipped with advanced avionics and electronics, including the global positioning system.

The RAF versions of the CH-47D are the Chinook HC.2 and HC.2A.

The CH-47D was a primary asset in Operation Enduring Freedom in Afghanistan and Operation Iraqi Freedom in Iraq having the most carrying capacity of any helicopter in the Army inventory. The Chinook was used in air assault missions, inserting large numbers of troops into forward fire bases and sustaining those soldiers by continuing to supply them with rations, water and ammunition. The CH-47D was particularly useful in the mountainous terrain of Afghanistan where high altitudes and temperatures limited the use of other helicopters such as the Blackhawk. Typically, in a combat situation CH-47D Chinooks will be escorted by attack helicopters such as the Apache for protection.

CH-47F

The current version of the Chinook is the CH-47D. The modernized CH-47F is flying since 2001 and should come off the remanufactuing line at Boeing in numbers from September 2006.

MH-47

The MH-47 variants of the H-47 are intended for special forces operations and have in-flight refuelling, a fast-rope rappelling system and other upgrades. The current model being used is the MH-47E. The MH-47G is in development.

The RAF ordered 8 Chinook HC.3s in 1995 for the special forces operations role. At a total cost of £259m these were effectively low cost equivalents to the MH-47G. This has proved to be a false economy as the helicopters were due to enter service in 1998, but in 2004 have yet to be cleared for anything other than training flights. An additional £130m is required to make them suitable for their mission.

The H-47 is now sold by Boeing Integrated Defense Systems.

Units using the Chinook

United States Army

• 7th Battallion, 101st AVN REGT
• A/B 2/52 AVN RGT. Cp Humphreys, Korea

Royal Air Force

• No. 7 Squadron
• No. 18 Squadron
• No. 27 Squadron
• No. 78 Squadron

Italian Army Aviation

• 1° Army Aviation Regiment “Antares”

Royal Netherlands Airforce

• No. 298 Squadron

Royal Australian Air Force

• C Squadron of the Army 5th Aviation Regiment, Townsville, Queensland

Republic of Singapore Air Force

• (127 Squadron) 12 units of CH-47SD operated in Sembawang Airbase

See also

• U.S. Army Aviation and Missile Command

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