The UH-1N emerged as a result of negotiations between the Canadian Forces and Bell Helicopter in 1968, with the aim of developing a new utility helicopter.
The Bell UH-1N Twin Huey is a military helicopter that serves as a utility transport.
It is equipped with two Pratt & Whitney Canada PT6 turboshaft engines, known as the PT6T-3/T400 Turbo Twin Pac, which are positioned side by side and connected to a shared gearbox and single output shaft.
These engines have a maximum power output of 1,342 kW (1,800 shp).
In the event of one power section failing, the remaining section can still provide 671 kW (900 shp) for up to 30 minutes or 571 kW (765 shp) continuously.
This capability allows the UH-1N to maintain its cruise performance even at maximum weight.
Furthermore, it is designed to operate under instrument flight rules and in nighttime conditions.
The UH-1N helicopter typically operates with a crew of four individuals, consisting of two pilots and two crew chiefs.
During flight, the crew chiefs are responsible for manning the weapons, with one pilot serving as a navigator and the other pilot actively controlling the aircraft.
The standard interior configuration includes 15 seats, allowing a single pilot to transport up to 14 passengers.
However, due to weight restrictions and weather conditions, it is uncommon for the UH-1N to carry the maximum number of passengers along with fuel and equipment.
When used for cargo transport, the cabin has a capacity of 220 ft³ (6.23 m³) and can accommodate up to six litters for medical evacuation purposes.
Additionally, the helicopter is capable of carrying an external load of up to 5,000 lb (2,268 kg).
In the United States Marine Corps (USMC) service, the cabin is equipped with three radios to facilitate communication between airborne commanders and ground troops.
Armament on the UH-1N typically includes a .50 calibre machine gun on the left side and a 7.62-millimetre machine gun on the right side.
In order to enhance safety measures, the UH-1N aircraft incorporates a significant level of redundancy within its crucial systems.
These encompass duplicate hydraulic, electrical, and fuel systems, ensuring a backup in case of any failures.
Additionally, fire suppression systems have been implemented to mitigate the risk of fire incidents.
To further enhance stability during flight, the USMC made the decision to modify a considerable number of their UH-1Ns by incorporating a stability control augmentation system.
This system provides servo inputs to the rotor head, aiding in stabilising the aircraft.
As a result of this modification, the traditional gyroscopic “stabilisation bar” situated on top of the main rotor head has been eliminated, with the computer system taking over the responsibility of maintaining stability.
Variants
Canadian variants
CUH-1N Twin Huey
The UH-1N utility transport helicopter was originally designated by the Canadian Armed Forces as the CUH-1N Twin Huey.
CH-135 Twin Huey
The Canadian variant of the UH-1N was the CH-135, with Canada acquiring 50 units that began delivery in 1971.
These aircraft were phased out by the Canadian Forces beginning in 1996, with the final decommissioning in December 1999.
The United States government purchased 41 of the remaining CH-135s in December 1999, which were then transferred to the Colombian National Army and Police.
At least one CH-135 was lost in combat.
The aircraft numbered 135135 was allocated to the Colombian National Police, operated by the Anti-Narcotics Directorate (DIRAN), and was destroyed by FARC insurgents on the ground on January 18, 2002, after being downed by gunfire.
U.S. variants
UH-1N Iroquois
The initial production model was utilised by the USAF, USN, and USMC.
Over time, the USMC, as the primary operator, has implemented numerous upgrades to the aircraft, such as enhanced avionics, defences, and a FLIR turret.
The USAF had plans to substitute their UH-1Ns with the Common Vertical Lift Support Platform for ICBM support services, while also considering a life extension for the existing fleet.
VH-1N
VIP transport configuration
HH-1N
Search and rescue variant.
UH-1Y Venom
The UH-1N is being replaced and upgraded as part of the H-1 upgrade program for the USMC.
This initiative is designed to align with a similar upgrade of the AH-1W attack helicopter to the AH-1Z Viper standard, featuring common engines and other major systems.
