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Bell UH-1N Iroquois / CH-135 Twin Huey

The Bell UH-1N Twin Huey is a medium military helicopter.

A member of the extensive Huey family, it first flew in 1969.

The CUH-1N Twin Huey (later CH-135 Twin Huey) was the original version, first ordered by the Canadian Forces.


Canadian variants

CUH-1N Twin Huey 

Original Canadian Armed Forces designation for the UH-1N utility transport helicopter.

CH-135 Twin Huey 

Canadian version of the UH-1N.

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.

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, defences, and a FLIR turret.

The USAF planned to replace their UH-1Ns with the Common Vertical Lift Support Platform to support the service’s ICBM activities, but also examined a life extension for their current fleet.


VIP transport configuration


SAR variant.

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.

Italian-built variants

Agusta-Bell AB 212 

Civil or military utility transport version. Built under license in Italy by Agusta.

Agusta-Bell AB 212EW 

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.

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.




6-8 combat-equipped troops


4,400 lb (1,996 kg) equivalent cargo


57 ft 8 in (17.58 m)


14 ft 5 in (4.39 m)


1 × Pratt & Whitney Canada T400-CP-400 coupled turboshaft engine,

1,250 shp (930 kW)

900 shp (671 kW) emergency rating for each power section

Main rotor diameter

48 ft 0 in (14.63 m)

Main rotor area

1,808 sq ft (168.0 m2)

Blade section


NACA 0010.8


NACA 0005.4 mod


Maximum speed

130 kn (150 mph, 240 km/h)

Cruise speed

110 kn (130 mph, 200 km/h)


248 nmi (285 mi, 459 km)

Service ceiling

17,300 ft (5,300 m)

Rate of climb

1,755 ft/min (8.92 m/s)


2.75-inch (70 mm) rocket pods,

0.50 in (12.7 mm) GAU-16 machine gun,

7.62 mm (0.308 in) GAU-17 minigun


7.62 mm (0.308 in) M240 lightweight machine gun.



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