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Boeing CH-47 Chinook

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CH-47 Chinook
File:Chinook1.jpg
U.S. Army Chinook .
Description
Role Medium transport helicopter
Crew 3 (pilot, copilot, crew chief/combat commander)
First flight September 21, 1961
Entered service
Manufacturer Boeing Integrated Defense Systems
Dimensions
Length 98 ft 9 in 30.1 m
Rotor diameter 60 ft 0 in 18.3 m
Height 18 ft 8 in 5.7 m
Weights
Empty 22,450 lb 10,185 kg
Loaded 26,680 lb 12,100 kg
Maximum takeoff 50,000 lb 22,680 kg
Capacity 44 troops or 24 litters and 2 attendants
Powerplant
Engines 2 Avco Lycoming T55-L-712 turboshafts
Power 2 x 3,750 hp 2 x 2,800 kW
Performance
Maximum speed 183 mph 295 km/h
Combat range miles km
Ferry range 1,280 miles 2,060 km
Service ceiling 8,500 ft 2,590 m
Rate of climb 1,980 ft/min 605 m/min
Avionics
Avionics
Armament
Guns 2 x M-60 machine guns
Bombs
Missiles
Rockets
Other

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.

Variants

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.

A/ACH-47A/ACH-47A

Originally known as the Armed/Armored CH-47A (or A/ACH-47A), four CH-47A helictopers were converted in late 1965 as gunships by Boeing Vertol, and 3 of the 4 were assigned to the 53rd Aviation Detachment in South Vietnam for testing. The four aircraft are known by both their serials and their nicknames and are as follows: 64-13145 "Cost of Living," 64-13149 "Easy Money," 64-13151 "Stump Jumper," and 64-13154 "Birth Control." The first aircraft was retained by Boeing in the United States for further weapon testing. By 1966 the 53rd had been redesignated the 1st Aviation Detachment (Provisional) and attached to the 228th Aviation Support Helicopter Battalion of the 1st Air Calvary Division. By 1968 only one gunship remained, and logisitical concerns prevented the conversion of anymore. The remaining ACH-47A was removed to the United States, and the program stopped.

The ACH-47A's armament consisted of 5 M60D 7.62x51mm machine guns or M2HB .50 caliber machine guns, provided by the XM32 and XM33 armament subsystems, 2 M24A1 20mm cannons, 2 XM159B/XM159C 19-Tube 2.75" rocket launchers or sometimes 2 M18/M18A1 7.62x51mm gun pods, and a single M75 40mm grenade launcher in the XM5/M5 armament subsystem.

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. 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.

Later, the CH-47C was modified in a so-called "Super-C" configuration which included newer up-rated Lycoming T55-L-712 engines and new, wide-chord fiberglass rotor blades (FRBs). FRBs are identifiable with a wider chord than the old metal blades, and an angled root-end (The metal blades the FRBs replaced had a squared-off root-end.)

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 Black Hawk. 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.

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

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

See main article, Deployment of the Chinook helicopter

Chinook is used by:

Problems with Chinook

See main article, Chinook crash on Mull of Kintyre

RAF Chinook HC.2 (ZA677)

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. [1] [2]

Pride of the RAF's helicopter fleet

Whilst Great Britain's Royal Air Force has many types of helicopters in active service, the Chinook has proven itself one of the most effective. One particular Chinook, registered ZA718 with the Royal Air Force and known by its original callsign 'Bravo November', has seen action in every major operation the RAF has been deployed to in the helicopter's 25-year service life. Bravo November started out spearheading the British landings on the Falkland Islands in 1982 and was being transported aboard the container ship Atlantic Conveyor along with three other Chinooks. However, the Argentine Air Force chose the Atlantic Conveyor as ia target for their deadly Exocet sea-skimming ant-ship missiles. By a stroke of pure luck, however, Bravo November was airborne on an engineering test flight at the time. Having survived the destruction of the ship it was being carried on, Bravo November managed to make it to safety on the aircraft carrier HMS Hermes. Unfortunately, ZA718 ran into trouble during a night mission transporting guns to the SAS when pilot Dick Langworthy, unable to see clearly through a thick snow shower, allowed Bravo November to descend and hit the sea at around 100 knots (139 kph), throwing up spray and flooding the engine intakes. However, Dick and his copilot managed to get the helicopter back in the air. With the radio damaged and unable to navigate, Bravo November returned to San Carlos and after a quick inspection revealed the impact had caused little more than dents to the fuselage and radio sytems.

If the Falklands conflict was not enough, ZA718 Bravo November went on to serve in Lebanon, Germany, Northern Ireland, Kurdistan and Iraq, being the first British helicopter to land Royal Marines ashore in Iraq.

Two pilots have been awarded the Distinguished Flying Cross at the controls of ZA718.

See also