This article is about the military versions of the Bell 212. For the civil versions, see Bell 212. - For an overview of the whole Huey family of aircraft see Bell Huey
The Bell UH-1N Twin Huey is a medium military helicopter that first flew in April, 1969.[1] The UH-1N has a fifteen seat configuration, with one pilot and fourteen passengers. In cargo configuration the UH-1N has an internal capacity of 220 ft³ (6.23 m³). An external load of 5,000 lb (2,268 kg) can be carried by the UH-1N. The CUH-1N (later CH-135) Twin Huey was the original version, first ordered by the Canadian Forces. [edit] Development Based on the stretched fuselage Bell 205, the Bell 212 was originally developed for the Canadian Forces (CF) under the designation CUH-1N Twin Huey. Later the CF adopted a new designation system and the aircraft was re-designated as the CH-135 Twin Huey.[2] The CF approved the development of the aircraft on 1 May 1968[1] and purchased 50 aircraft, with deliveries commencing in May 1971.[3] The US military came very close to not procuring the Twin Huey. The purchase of the aircraft for US military use was opposed by the Chairman of the House Armed Services Committee at the time, L. Mendel Rivers. Rivers took this position because the aircraft powerplant, the Pratt & Whitney Canada PT6T was produced in Canada. The Canadian government had not supported US involvement in Vietnam and had opposed US policies in southeast Asia, as well as accepting US draft dodgers. Rivers was also concerned that procurement of the engines would result in a negative trade deficit situation with Canada. Congress only approved the purchase when it was assured that a US source would be found for the PT6T/T400 engines. As a result the United States military services ordered 294 Bell 212s under the designation UH-1N, with deliveries commencing in 1970.[3] Unlike in the Canadian Forces, in US service, the UH-1N retained the official name "Iroquois" from the single engined UH-1 variants, although US service personnel refer to the aircraft as a "Huey" or "Twin Huey".[4] The Bell 412 is a further development of the Bell 212, the major difference being the composite four-blade main rotor.[3] [edit] Design A USAF UH-1N during Exercise WOUNDED EAGLE '83 A Marine UH-1N sitting on the flight line at NAS Whiting Field, Florida, in 1982 The UH-1N's main rotor is powered by a PT6T-3/T400 Turbo Twin Pac made up of two Pratt & Whitney Canada PT6 turboshaft power turbines driving a single output shaft. They are capable of producing up to 1,342 kW (1,800 shp). Should one engine fail the remaining engine can deliver 671 kW (900 shp) for 30 minutes or 571 kW (765 shp) enabling the UH-1N to maintain cruise performance at maximum weight.[3] The United States Marine Corps (USMC) modified a large number of their UH-1Ns with a Stability Control Augmentation System (SCAS) which provides servo inputs to the rotor head to help stabilize the aircraft during flight. This modification removed the gyroscopic "Stabilization Bar" on top of the main rotor head, instead relying on the computer system for stability. [edit] Operational history [edit] Military service USMC UH-1Ns were used by the USMC during its 2003 invasion of Iraq. UH-1Ns provided reconnaissance, and communications support to Marine ground troops. They were also called upon to provide close air support during heavy fighting in Nasiriyah.[5] [edit] Significant flights On 6 March 1972, Hendrick V. Gorick of the United States Navy Antarctic Development Squadron Six (VXE-6) jumped at an altitude of 20,500 ft (6,248 m) from a UH-1N helicopter. In doing so he set a record for parachute jumping over the Antarctic continent.[citation needed] [edit] Variants [edit] U.S. variants - UH-1N Iroquois
- Initial production model, used by the USAF, USN, and USMC. Over the years the primary operators, the USMC has developed a number of upgrades for the aircraft including improved avionics, defenses, and a FLIR turret.
- VH-1N
- VIP transport configuration[1]
- HH-1N
- SAR variant.[1]
- UH-1Y Venom
- Essentially a massive UH-1N replacement and upgrade as part of the H-1 upgrade program for the USMC, designed to coincide with a similar upgrade for the AH-1W attack helicopter to AH-1Z Viper standard.
[edit] Foreign variants - Agusta-Bell AB 212
- Civil or military utility transport version. Built under license in Italy by Agusta.
- Agusta-Bell AB 121EW
- Electronic warfare version for Turkey.
- Agusta-Bell AB 212ASW
- Anti-submarine warfare, anti-shipping version of the AB 212 helicopter, built under license in Italy by Agusta. Operated by the Italian Navy, Hellenic Navy and Islamic Republic of Iran Navy, Greece, Iran, Italy, Peru, Spain, Turkey, and Venezuela.[3]
- The AB-212ASW is a Model 212 Twin Huey with a prominent radome above the cockpit. Early production had a dome-shaped radome, while later production had a flatter "drum" radome. A left side winch is used for dipping the Bendix ASQ-18 sonar. Other changes include structural reinforcement for a gross weight of 11,197 lbs (5080 kg), ECM, shipboard deck tie-down attachments and corrosion protection. Armament is two Mk 44 or Mk 46 torpedoes or two depth charges in the ASW role and four AS.12 air-to-surface wire-guided missiles for the anti-shipping role.[6][7]
- CH-135 Twin Huey
- Canadian version of the UH-1N.[1][3]
- Canada purchased 50 CH-135s with deliveries starting in 1971. The aircraft were retired from the Canadian Forces starting in 1996 and struck off strength in December 1999. 41 of the surviving CH-135s were acquired by the US government in December 1999 and transferred to the National Army of Colombia and Colombian National Police. At least one CH-135 was destroyed in combat. 135135 was transferred to the Colombian National Police and flown by the Dirección Antinarcóticos (DIRAN). It was destroyed on the ground by FARC rebels on 18 January 2002, following an incident in which it was forced down by gunfire. Two CH-135s are on display in museums, one at the Canada Aviation Museum in Ottawa and one at the National Air Force Museum of Canada at CFB Trenton.[8]
- CUH-1N Twin Huey
- Original Canadian Armed Forces designation for the UH-1N utility transport helicopter.[1][3]
[edit] Operators Austrian UH-1N (Bell 212) AB.212 of Italian Air Force, airshow at Pratica di Mare AFB, Italy A UH-1N helicopter, with Philippine Army officers aboard, prepares to land The USAF's 20th Special Operations Squadron conducts a training exercise using a specially-painted UH-1N Angola Argentina Austria Bangladesh Bahrain Bolivia Bosnia and Herzegovina Brunei Canada Colombia Croatia Ecuador Germany Greece Guatemala Guyana Iran Iraq - Iraqi Navy operated Agusta-Bell 212ASW variant between 1984 and 2003
Israel Italy Japan Lebanon Libya Malta - Armed Forces of Malta operates Agusta-Bell 212s with mixed crews on SAR duties by an Italian Technical Assistance Mission.
Morocco Panama Peru Philippines Saudi Arabia Serbia Singapore Somalia South Korea Spain Sri Lanka Sudan Thailand Tunisia Turkey Uganda United Arab Emirates United Kingdom United States Uruguay Yemen [edit] Aircraft on display [edit] Specifications (USMC UH-1N, as modified) Data from USMC UH-1N Fact Sheet,[21] The International Directiory of Military Aircraft, 2002-2003[22] General characteristics - Crew: 4 (Pilot, copilot, crew chief, gunner)
- Capacity: 6-8 combat-equipped troops, or equivalent cargo
- Length: 41 ft 8 in (12.69 m)
- Rotor diameter: 48 ft 0 in (14.6 m)
- Height: 14 ft 5 in (4.4 m)
- Disc area: 1,808 ft² (168.0 m²)
- Empty weight: 6,000 lb (2,721.5 kg)
- Loaded weight: 10,500 lb (4,762.7 kg)
- Useful load: 4500 lb (2038.0 kg)
- Max takeoff weight: 10,500 lb (4,762.7 kg)
- Powerplant: 2× Pratt & Whitney Canada T400-CP-400 turboshaft, 900 shp (671 kW), (total 1,250 shp) each
Performance Armament
- 2.75-inch rocket pods,
- GAU-16 .50 Cal. Machinegun,
- GAU-17 7.62mm minigun or M240 7.62mm lightweight machinegun
[edit] Gallery | | CH-135 Twin Huey 135137 in the original blue-gray and green camouflage pattern worn by these aircraft prior to 1986/88. | CH-135 Twin Huey 135135 in the early-style SAR markings, 1988. This aircraft was serving with Base Rescue Goose Bay and had formerly been assigned to 424 Transport & Rescue Squadron, CFB Trenton. | | CH-135 Twin Huey 135103 in special flight test markings. The aircraft was used by the Aerospace Engineering Test Establishment at CFB Cold Lake, 1987. | CH-135 Twin Huey 135103 after repainting in anti-IR olive and green scheme. | CH-135 Twin Huey badge worn by some Canadian Forces air and ground crew, 1980s | | [edit] See also Related development Related lists [edit] References - ^ a b c d e f Mutza, Wayne: UH-1 Huey in action, pages 31-33. Squadron/Signal Publications, Carrollton, Texas, 1986. ISBN 0-89747-179-2
- ^ Air Force Public Affairs / Department of National Defence (May 19, 2004). "Bell CH-135 Twin Huey". http://www.airforce.forces.gc.ca/site/equip/historical/twinhueylst_e.asp. Retrieved 2007-10-01.
- ^ a b c d e f g Drendel, Lou: Huey, pages 14-17. Squadron/Signal Publications, Carrollton, Texas, 1983. ISBN 0-89747-145-8
- ^ Drendel, Lou: Huey, page 9. Squadron/Signal Publications, Carrollton, Texas, 1983. ISBN 0-89747-145-8
- ^ Stout, Jay A. Hammer from Above, Marine Air Combat Over Iraq. Ballantine Books, 2005. ISBN 978-0-89141-871-9.
- ^ Green, William: Observers Aircraft, page 229. Frederick Warne Publishing, 1980. ISBN 0 7232 1604 5
- ^ Wood, Derek: Jane's World Aircraft Recognition Handbook, page 490. Jane's Publishing Company 1985. ISBN 0-7106-0343-6
- ^ a b c Walker, RWR (June 2006). "Canadian Military Aircraft Serial Numbers Canadian Armed Forces CH-135 Twin Huey detailed list". http://www.ody.ca/~bwalker/CF_twin_huey.html. Retrieved 2008-12-02.
- ^ a b Air Force Public Affairs / Department of National Defence (June 13, 2007). "403 Squadron Activated as Operational Training Squadron". http://www.airforce.forces.gc.ca/1wing/squadron/403hist4_e.asp. Retrieved 2007-10-23.
- ^ Air Force Public Affairs / Department of National Defence (June 13, 2007). "408 Tactical Helicopter Squadron (THS) History". http://www.airforce.forces.gc.ca/1wing/squadron/408hist_e.asp. Retrieved 2007-10-23.
- ^ Air Force Public Affairs / Department of National Defence (May 30, 2006). "424 Squadron History". http://www.airforce.forces.gc.ca/8wing/squadron/424hist_e.asp. Retrieved 2007-10-23.
- ^ Air Force Public Affairs / Department of National Defence (June 13, 2007). "History of 427 Special Operations Aviation Squadron". http://www.airforce.forces.gc.ca/1wing/squadron/427hist_e.asp. Retrieved 2007-10-23.
- ^ Air Force Public Affairs / Department of National Defence (June 13, 2007). "430 Squadron". http://www.airforce.forces.gc.ca/1wing/squadron/430_e.asp. Retrieved 2007-10-23.
- ^ a b Air Force Public Affairs / Department of National Defence (June 15, 2007). "444 Squadron History". http://www.airforce.forces.gc.ca/5wing/squadron/444hist_e.asp. Retrieved 2007-10-23.
- ^ AEROWARE / RCAF.com (undated). "Utility Squadron VU 32". http://www.rcaf.com/squadrons/otherunits/vu32.htm. Retrieved 2007-10-24.
- ^ Shaw, Robbie: Superbase 18 Cold Lake- Canada's Northern Guardians, page 86. Osprey Publishing, London, 1990. ISBN 0-85045-910-9
- ^ Air Force Public Affairs / Department of National Defence (June 15, 2007). "417 Combat Support Squadron - History". http://www.airforce.forces.gc.ca/4wing/squadron/417hist_e.asp. Retrieved 2007-10-23.
- ^ 10 Tactical Air Group: Canadian Contingent Multinational Force and Observers Handbook (unclassified), page A-1. DND, Ottawa, 1986.
- ^ Ecuadorian military aviation OrBat
- ^ Canada Aviation Museum (undated). "Bell CH-135 “Twin Huey”". http://www.aviation.technomuses.ca/collections/artifacts/aircraft/BellCH-135TwinHuey/. Retrieved 2008-12-13.
- ^ USMC UH-1N fact sheet, USMC. Retrieved 4 September 2008.
- ^ Frawley, Gerard: The International Directiory of Military Aircraft, page 33. Aerospace Publications Pty Ltd, 2002. ISBN 1-875671-55-2
- Chant, Christopher, Fighting Helicopters of the 20th Century, Graham Beehag Books, Christchurch, Dorset, England (1996).
- Debay, Yves, Combat Helicopters, France: Histoire & Collections (1996)
- Eden, Paul. "Bell 212/412", Encyclopedia of Modern Military Aircraft. Amber Books, 2004. ISBN 1904687849.
- Francillon, Rene, J. Vietnam: The War in the Air, New York: Arch Cape Press (1987)
- Mesko, Jim, Airmobile: The Helicopter War in Vietnam. Squadron Signal Publications (1984).
- Specifications for 204, 205 and 214 Huey Plus
- Mutza, Wayne. UH-1 Huey in Colors. Carrolton, TX: Squadron Signal. ISBN 0-89747-279-9
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