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.
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.
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. The CF approved the development of the aircraft on 1 May 1968
[Mutza, Wayne: UH-1 Huey in action, pages 31-33. Squadron/Signal Publications, Carrollton, Texas, 1986. ISBN 0-89747-179-2] and purchased 50 aircraft, with deliveries commencing in May 1971.
[Drendel, Lou: Huey, pages 14-17. Squadron/Signal Publications, Carrollton, Texas, 1983. ISBN 0-89747-145-8]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.
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".
The
Bell 412 is a further development of the Bell 212, the major difference being the composite four-blade main rotor.
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.
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
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.
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.
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.
VH-1N
VIP transport configuration
HH-1N
SAR variant.
UH-1Y VenomEssentially 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.
Foreign variants
thumb|Agusta Bell AB 212 ASW of the Spanish Navy.
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.
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.
[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]CH-135 Twin Huey
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.
[ ] CUH-1N Twin Huey
Original Canadian Armed Forces designation for the UH-1N utility transport helicopter.
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
- *403 (Helicopter) Operational Training Squadron
- *422 Tactical Helicopter Squadron (disbanded 16 August 1980)
- *424 Transport & Rescue Squadron
- *430 Tactical Helicopter Squadron (430e Escadron Tactique d'Hélicoptères)
- *444 Combat Support Squadron
- *VU32 - Navy Utility Squadron
- *Aerospace Engineering Test Establishment
- Iraqi Navy operated Agusta-Bell 212ASW variant between 1984 and 2003
- Armed Forces of Malta operates Agusta-Bell 212s with mixed crews on SAR duties by an Italian Technical Assistance Mission.
Aircraft on Display
Specifications (USMC UH-1N, as modified)
U.S. Navy HH-1N cockpit.
HH-1N rotor head.
Gallery
See also
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