CH-47 Chinook

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CH-47 Chinook

Field artillery section slingloading a M-198 howitzer for airlift by a CH-47 Chinook
Type	Cargo helicopter
Manufacturer	Boeing Helicopters
Maiden flight	1961-09-21
Introduced	1962
Status	Active service
Primary users	United States Army Royal Air Force
Number built	more than 1,000^[1]
Developed from	CH-46 Sea Knight
Variants	Boeing Chinook (UK variants)

The Boeing CH-47 Chinook is a versatile, twin-engine, tandem rotor heavy-lift helicopter. The contra-rotating rotors eliminate the need for a rear vertical rotor, allowing all power to be used for lift and thrust, giving a top speed of 170 knots (196 mph, 315 km/h). Its primary roles include troop movement, artillery emplacement, and battlefield resupply. Chinooks have been sold to 16 nations, the largest users of which are the U.S. Army and the Royal Air Force (see Boeing Chinook (UK variants)). A commercial model, the Boeing 234 Chinook, is used worldwide for logging, construction, fighting forest fires, and supporting petroleum exploration operations. The H-47 is now sold by Boeing Integrated Defense Systems.

[edit] Development

[edit] YHC-1A

The original Model 107/YHC-1A was rejected by the Army as being too small for its needs. The YHC-1A was then evaluated by the U.S. Marine Corps, and ordered as the HRB-1 (CH-46A after 1962).

[edit] YHC-1B/YCH-47A

The Army then ordered the larger Model 114/HC-1B. The pre-production Boeing Vertol YCH-1B made its initial hovering flight on September 21, 1961. In 1962 the HC-1B was redesignated the CH-47A under the 1962 United States Tri-Service aircraft designation system.

[edit] Variants

[edit] CH-47A

CH-47A The all-weather medium-lift CH-47A Chinook entered service in Vietnam about 1966. The CH-47A was powered initially by Lycoming T55-L-5 engines rated at 2200 shp (1,640 kW) but then replaced by the T55-L-7 rated at 2650 shp (1,980 kW) engines or T55-L-7C engines rated at 2,850 SHP. The CH-47A had a maximum gross weight of 33,000 pounds.

A/ACH-47A and ACH-47A Originally known as the Armed/Armored CH-47A (or A/ACH-47A), four CH-47A helicopters were converted to gunships by Boeing Vertol in late 1965. Three were assigned to the 53rd Aviation Detachment in South Vietnam for testing, with the remaining one retained in the U.S. for weapons testing. By 1966, the 53rd was redesignated the 1st Aviation Detachment (Provisional) and attached to the 228th Aviation Support Helicopter Battalion of the 1st Air Cavalry Division. By 1968, only one gunship remained, and logistical concerns prevented more conversions. It was returned to the United States, and the program stopped. The ACH-47A carried five M60D 7.62x51mm machine guns or M2HB .50 caliber machine guns, provided by the XM32 and XM33 armament subsystems, two M24A1 20 mm cannons, two XM159B/XM159C 19-Tube 2.75" rocket launchers or sometimes two M18/M18A1 7.62x51 mm gun pods, and a single M75 40 mm grenade launcher in the XM5/M5 armament subsystem. The surviving aircraft, Easy Money, has been restored and is on display at the U.S. Army Aviation and Missile Command, near Huntsville, Alabama.

[edit] CH-47B

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 asymmetrical 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-mounted M60D 7.62 mm NATO machine guns on the M24 armament subsystem and a ramp-mounted M60D using the M41 armament subsystem. Some CH-47 "bombers" were equipped to drop riot control gas or napalm from the rear cargo ramp onto Viet Cong bunkers. 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 $3.6 billion during the war.

[edit] CH-47C

CH-47C Three variants of the "C model" were in evidence. The original "C" had Lycoming T55-L-7C engines delivering 2,850 SHP. The "Super C" included Lycoming T55-L-11 engines delivering 3,750 SHP, an upgraded maximum gross weight of 46,000 pounds and a pitch stability augmentation system (PSAS). Difficulties with the T55-L-11 engines, which were hurredly brought to war to increase payload, were temprarily removed from the "Super C" prior to 1970 and the very reliable Lycoming T55-L-7C's were installed until the L-11 engine diffiulties could be quantified and corrected. This L-7C engine configuration was affectionately referred to as the "baby C" although it was still a Super C. It still distinguised itself from the "C" in that it had PSAS, and an uprated maximum gross weight. The CH-47 A, B, and all variants of the C were not able to receive certification from the FAA for civil use due to the non redundant hydraulic flight boost system drive. A redesign of the hydraulic boost system drive was incorporated in the CH-47D which allowed that model to achieve FAA certification as the Boeing Model 234.

The CH-47 A,B, and all varients of the C saw wide use during the Vietnam war. They replaced the H-21 Shawnee in the combat assault support role.

CH-47C Plus Export version of the CH-47C Chinook for the Italian Army.

[edit] CH-47D

A US Army CH-47D Chinook, belonging to B Company 3/2 GSAB, resting near a river on a cold South Korean morning.

Chinook CH-47D of the Royal Netherlands Air Force

A U.S. military Chinook helicopter stands ready to receive medical supplies and whooping cough vaccine donated by the World Health Organization in Feyzabad, Afghanistan

CH-47D The CH-47D was originally powered by two T55-L-712 engines, but most are now fitted with the T55-GA-714A. Models CH-47A, CH-47B, and CH-47C, all used the same airframe, but later models featured upgraded engines. With its triple-hook cargo system, the CH-47D can carry heavy payloads internally and up to 26,000 pounds externally, for example, bulldozers and 40-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, 30 rounds of ammunition, and an 11-man crew. Like most US Army helicopters, the Chinook has advanced avionics and electronics, including the Global Positioning System.

The CH-47D saw wide use in Operation Enduring Freedom in Afghanistan and Operation Iraqi Freedom in Iraq. The Chinook was used in air assault missions, inserting troops into fire bases and later bringing food, water, and ammunition. It is typically escorted by attack helicopters such as the Apache for protection. The CH-47D was particularly useful in the mountainous terrain of Afghanistan where high altitudes and temperatures limited the use of the Black Hawk.

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

MH-47D and MH-47E The MH-47 variants are intended for special forces operations and have in-flight refueling, a fast-rope rappeling system and other upgrades. The current model being used by the US Army is the MH-47E. The MH-47D was an early special operations version for the US Army. The MH-47G is in development.

The RAF ordered eight Chinook HC.3s in 1995 for the special forces operations role. At a total cost of £259 million 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 £130 million is required to make them suitable for their mission.

CH-47SD The CH-47SD is a modified variant of the CH-47D, with extra-large fuel tanks and higher payload capacities. It is in use by the Republic of Singapore Air Force, and the Republic of China.

CH-47DG The CH-47DG is an upgraded version of the CH-47C for the Greek Army.

HH-47D The HH-47D is a search and rescue version for the South Korean Air Force.

[edit] CH-47F

CH-47F The CH-47F, an upgraded D model, first flew in 2001 and the first production model was rolled out on June 15, 2006 at the Boeing facility in Ridley Park, Pennsylvania, and had its maiden flight on October 23, 2006.^[2] The CH-47F was designed to extend the service life of the Chinook class beyond 2030. Amongst its upgrades are new 4,868 horsepower Honeywell engines (an improvement of over 1,100 hp per engine), improved digital avionics, and a more modern airframe manufacturing process designed to extend operational life, reduce vibration effects and cut maintenance costs.

The CH-47F has a maximum payload capacity of 25,000 pounds or 10,615 kg.

The United States Army has ordered 452 of the 'F' models. Additional orders are expected from Canada, the Netherlands, and the United Kingdom.

MH-47G The MH-47G special forces operations version is in development for the US Army.

[edit] HH-47

HH-47 On November 9, 2006, the HH-47, a new variant of the Chinook based on the MH-47G, was selected by the United States Air Force as the winner of the Combat Search and Rescue (CSAR-X) competition. Four development HH-47s will be built, with the first of 141 production aircraft to enter service in 2012.^[3]^[4]

[edit] Other export models

CH-47J and CH-47JA The CH-47J is a medium-transport helicopter for the Japan Ground Self Defence Force, and the Japan Air Self Defence Force. The CH-47JA is a long range version of the CH-47J, fitted with enlarged fuel tanks. Both versions are built under licence in Japan by Kawasaki.

CH-147 Eight CH-47C Chinooks were delivered to the Canadian Armed Forces in 1974. The Chinooks were in Canadian service from 1974 to 1991; they were designated CH-147. These aircraft were subsequently sold to the Netherlands and are now operated by the Royal Netherlands Air Force as CH-47Ds. On July 5, 2006, the Canadian government issued a notice that it intends to purchase 16 Chinooks^[5].

[edit] Civilian Models

Model 234LR (Long Range) Commercial transport helicopter. The Model 234LR can be fitted out, as an all-passenger, all-cargo, or cargo/passenger transport helicopter.

Model 234ER (Extended Range) Commercial transport version.

Model MLR (Multi Purpose Long Range) Commercial transport version.

Model 234UT (Utility Transport) Utility transport helicopter.

Model 414 The Model 414 is the international export version of the CH-47D. It is also known as the CH-47D International Chinook.

[edit] Users

[edit] Military operators past and present

[edit] Units using the Chinook

Main article: Deployment of the Chinook helicopter

[edit] Miscellaneous

[edit] Problems with the Chinook

Main article: Chinook crash on Mull of Kintyre

In June 1994 a Royal Air Force Chinook crashed into the Mull of Kintyre, killing 29. This was initially dismissed as pilot error, but an investigation by Computer Weekly uncovered evidence sufficient to convince a House of Lords enquiry that it may have been caused by a software bug in the aircraft's FADEC. [3] [4]

[edit] Reputation of the Chinook

Main article: RAF Boeing Chinook (UK variants)

One of the Chinooks, Bravo November, in service with the RAF has seen action in every major operation the RAF has been deployed to during the helicopter's 25-year service life.

[edit] Specifications (CH-47D)

General characteristics

Crew: 3: pilot, copilot, flight engineer [5]
Capacity:
- 33 troops or
- 24 litters and 3 attendants
Length: 98 ft 10 in (30.1 m)
Rotor diameter: 60 ft 0 in (18.3 m)
Height: 18 ft 11 in (5.7 m)
Disc area: 2,800 ft² (260 m²)
Empty weight: 22,450 lb (10,185 kg)
Loaded weight: 26,680 lb (12,100 kg)
Max takeoff weight: 50,000 lb (22,680 kg)
Powerplant: 2× Lycoming T55-GA-714 turboshafts, 5,069 hp (2,800 kW) each

Performance

Maximum speed: 170 knots VNE (196 mph, 315 km/h)
Range: 1,280 mi (1,110 nm, 2,060 km)
Service ceiling: 8,500 ft (2,590 m)
Rate of climb: 1,980 ft/min (10.1 m/s)
Disc loading: 9.5 lb/ft² (47 kg/m²)
Power/mass: 0.28 hp/lb (460 W/kg)

[edit] References

^ "New Boeing CH-47F takes flight", Aerotech News and Review, November 3, 2006, page 3
^ [1] Boeing News Release
^ [2] Global Security.org
^ Medium to Heavy Lift Helicopter (MHLH) - ACAN MERX Website - Government of Canada

[edit] External links

[edit] Related content

	Wikimedia Commons has media related to: CH-47 Chinook