Bell UH-1N Twin Huey

UH-1N Iroquois
CH-135 Twin Huey
Marine UH-1Ns lifting from a field outside Baghdad on 10 April 2003.
Role Utility helicopter
National origin United States / Canada
Manufacturer Bell Helicopter
First flight April 1969
Introduction October 1970
Primary users United States Marine Corps
Canadian Forces
United States Navy
United States Air Force
Developed from Bell UH-1H Iroquois
Variants Bell 212
Bell UH-1Y Venom

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.

Contents

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] The UH-1N has also been developed into the upgraded, four-blade UH-1Y.[5]

Design

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.

Operational history

Military service

The United States Air Force employs UH-1Ns to fulfill its ICBM mission, providing a utility helicopter for transport between bases such as Minot AFB, Francis E. Warren AFB and Malmstrom AFB to missile launch sites in North Dakota, Montana, Wyoming, Nebraska, and Colorado. The UH-1N is also used by the 36th Rescue Flight (36 RQF) at Fairchild AFB, WA for conducting Search-and-Rescue (SAR) and medical evacuation missions.

During the 1982 Falklands War, the Argentine Air Force deployed two Bell 212 to Goose Green grass airstrip from where they performed general support duties including the recovery of many downed pilots. By the end of the hostilities both aircraft were still intact and both captured by the British.[6]

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.[7]

Variants

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. The USAF plans to replace their UH-1Ns with the Common Vertical Lift Support Platform to support the service's ICBM activities.[8]
VH-1N
VIP transport configuration[1]
HH-1N
SAR variant.[1]
UH-1Y Venom
A 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, with common engines and other major systems.

Canadian variants

CUH-1N Twin Huey
Original Canadian Armed Forces designation for the UH-1N utility transport helicopter.[1][3]
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.[9]

Italian-built 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, 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.[10][11]

Operators

 Angola
 Argentina
 Argentina- Chile

Fuerza de Paz Binacional Cruz del Sur operates Bell 212s.

 Austria
 Bangladesh
 Bahrain
 Bolivia
 Brunei
 Canada
 Colombia
 Croatia
 Ecuador
 Gabon
 Germany
 Greece
 Guatemala
 Guyana
 Iran
 Iraq
 Israel
 Italy
 Jamaica
 Japan
 Lebanon
 Libya
 Malta
 Mexico
 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

Aircraft on display

Specifications (USMC UH-1N, as modified)

Data from USMC UH-1N Fact Sheet,[28] The International Directiory of Military Aircraft, 2002-2003[29]

General characteristics

Performance

Armament

Gallery

See also

Related development

Related lists

References

  1. ^ a b c d e f Mutza 1986, pp. 31-33.
  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. 
  3. ^ a b c d e f g Drendel 1983, pp. 14-17.
  4. ^ Drendel 1983, p. 9.
  5. ^ Eden 2004, p. 47.
  6. ^ FAA oficial magazine
  7. ^ Stout, Jay A. Hammer from Above, Marine Air Combat Over Iraq. Ballantine Books, 2005. ISBN 978-0-89141-871-9.
  8. ^ USAF 2011 Budget justification, page 4-1
  9. ^ 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. 
  10. ^ Green, William: Observers Aircraft, page 229. Frederick Warne Publishing, 1980. ISBN 0-7232-1604-5
  11. ^ Wood, Derek: Jane's World Aircraft Recognition Handbook, page 490. Jane's Publishing Company 1985. ISBN 0-7106-0343-6
  12. ^ 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. 
  13. ^ 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. 
  14. ^ 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. 
  15. ^ 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. 
  16. ^ 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. 
  17. ^ 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. 
  18. ^ AEROWARE / RCAF.com (undated). "Utility Squadron VU 32". http://www.rcaf.com/Squadrons/squadronDetail.php?Utility-Squadron-VU-32-107. Retrieved 2007-10-24. 
  19. ^ Shaw, Robbie: Superbase 18 Cold Lake- Canada's Northern Guardians, page 86. Osprey Publishing, London, 1990. ISBN 0-85045-910-9
  20. ^ 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. 
  21. ^ 10 Tactical Air Group: Canadian Contingent Multinational Force and Observers Handbook (unclassified), page A-1. DND, Ottawa, 1986.
  22. ^ Ecuadorian military aviation OrBat
  23. ^ Wants Proven Security For Mexico Border "U.S. Wants Proven Security For Mexico Border"
  24. ^ "The Merida Initiative: Expanding the U.S./Mexico Partnership"
  25. ^ a b "World Military Aircraft Inventory". 2010 Aerospace Source Book. Aviation Week and Space Technology, January 2010.
  26. ^ British Army (2010). "Bell212". http://www.army.mod.uk/equipment/aircraft/4607.aspx. Retrieved 2010-01-02. 
  27. ^ Canada Aviation Museum (undated). "Bell CH-135 “Twin Huey”". http://www.aviation.technomuses.ca/collections/artifacts/aircraft/BellCH-135TwinHuey/. Retrieved 2008-12-13. 
  28. ^ USMC UH-1N fact sheet, USMC. Retrieved 4 September 2008.
  29. ^ Frawley, Gerard: The International Directiory of Military Aircraft, page 33. Aerospace Publications Pty Ltd, 2002. ISBN 1-875671-55-2

External links