Bell UH-1 Iroquois (Huey)
Multi-Role / Utility / Attack / Transport Helicopter
One of the most successful helicopter designs of all time, the Bell UH-1 series and its offshoots have served across all parts of the globe.
Authored By: Staff Writer | Last Edited:
The UH-1 Iroquois "Huey" became an important part of American military actions beginning in 1960 and expanding throughout the latter part of the Cold War years. The ubiquitous system became synonymous with the American effort in Vietnam, no doubt due to her inherent capabilities to take on just about any needed role. Despite her consistent association with that war, her legacy has rightfully developed into so much more thanks to her use throughout the modern world in both military and civilian roles encompassing search and rescue, assault, transport and humanitarian efforts. Despite her official "Iroquois" name, the nickname of "Huey" stuck thanks to her early "HU-1" designation (later redesignated to UH-1 in 1962. Hence the Iroquois name was - and is - seldom used to this day when referencing the UH-1 series of helicopters.
The Huey developed from advances made in turbine technology throughout the 1950's. Bell produced the turbine-powered Model 47 (XH-13F) in 1954 to which the United States Army took special interest in. The need for a MedEvac helicopter was on the US Army wish list and, as such, Bell was tagged with developing a solution - and the prototype XH-40 (Bell Model 204) was born. First flight of XH-40 occurred on October 22nd, 1956 and were followed by two additional XH-40 prototypes, fitting the Lycoming 700 horsepower XT-53-L-1 engine. A further six developmental models were then ordered as YH-40 evaluation aircraft. These were essentially the same as the XH-40 prototypes but had their cabin space extended a full 12-inches. One of these YH-40's was set aside as a test bed featuring turbofan engines and wing assemblies becoming Bell Model 533. The Model 204 entered production for the US Army as the HU-1A, becoming the first turbine-powered helicopter in service with any US military branch. First deliveries would fall to the 101st Airborne Division, the 57th Medical Detachment and the 82nd Airborne Division. The 57th Medical Detachment would be the first to field the system in Vietnam beginning in March 1962.
By all respects, design of the Huey was quite utilitarian although more pleasing to the eye that other rotary-wing offerings developed during the 1950s. Aircraft construction was comprised of the main fuselage housing the cockpit and passenger cabin (along with their associated systems and equipment), the engine and rotor mast section and the empennage, or tail section containing the tail rotor. The pilot and co-pilot were seated at the extreme forward of the design with a windowed cockpit providing excellent vision forward, above, to the sides and forward-below. Entry for either cockpit seating position was made through an automobile-style hinged door. The cabin featured a large sliding windowed door on either side of the fuselage for easy access (in most Vietnam-era pictures, these doors are almost always lest open). The single engine was mounted atop the rear portion of the crew cabin root with the rotor mast extending upwards forward of the engine. The rotor blades on initial models were simple two-blade arrangements with a rotor mast for added stability (the latest Huey version sports a four-blade rotor system). The engine exhausted rearwards over the base of the empennage. The tail section itself made up nearly half the length of the entire fuselage and featured horizontal fins about half-way down the tail section. The section ended with a single vertical fin adorned with the two-blade tail rotor system mounted to the portside (the latest Huey sports a four-blade tail rotor). The undercarriage consisted of a pair of fixed landing skids - braced in two areas - allowing for landing and take-off from just about any type of surface making it useful to both land and sea-based operators. Throughout its production run - with the exception of the twin-engine Huey - the base UH-1 Huey series would retain this unique and very identifiable design.
With its transport origins and inherently large cabin space, the Huey was designed from the outset to serve occupants in quantity. Passenger space was equivalent to 14 combat-ready troops. This arrangement could be supplanted by up to 6 medical litters when in the MedEvac role. The base crew could comprise 1 to 4 personnel as needed and depending on the role and equipment utilized.
The UH-1 airframe proved highly adaptable throughout its tenure, particularly when a showcase piece in the Vietnam War as helicopter gunships. Standard armaments included the use of pintle-mounted M60 7.62mm machine guns or specialized external mountings for dual 7.62mm miniguns mounts, 2-, 7-, or 19-shot 2.75" rocket pods and 7.62mm machine guns in quad-mountings. In the Vietnam War, US Army Hueys were dubbed "Cobras" when fitted with machine gun armament and "Hogs" when sporting rocket pods while unarmed Hueys became "Slicks" (similarly, the USN and USMC called their transports "Dolphins" and their gunships "Sharks"). Many other weapon arrangements were trialed with the Huey airframe throughout the Vietnam War resulting in a plethora of experimental systems with a laundry list of x-type designations. These trials included the use of air-to-surface missiles, 7.62mm minigun gun pods, 20mm and 30mm cannon armament, mine dispensers, heavy caliber 12.7mm miniguns and 40mm grenade launchers. In all, the series was already proving its adaptability to just about any role imaginable even though many of these impressive armament arrangements were never accepted into any official role.
Of all conflicts that the Huey has ever been showcased in, no doubt its involvement in the Vietnam War truly cemented its legacy. The Huey would go on to become the symbolic icon of the American involvement in the war with imagery of troops exiting the hovering helicopter displayed across American televisions on a seemingly nightly basis. Hueys in Vietnam were called upon to fulfill a variety of roles that most any aircraft of the time could match. UH-1's were utilized in their intended troop transport roles but were also featured in the all-important roles of medical evacuation, search and rescue efforts, general transport, VIP transport, command and control and as helicopter gunships. Huey use, armaments and tactics generally changed throughout the course of the war based on battlefield experience and adapted to needs of the moment. Models showcased in the war covered the UH-1A, B, C, D and H models. UH-1B and UH-1C Hueys were eventually supplanted in the gunship role by the dedicated AH-1 Cobra twin-seat attack helicopter gunships beginning to arrive in August of 1967 (AH-1G). In all, over 3,300 UH-1 Hueys were lost in the conflict along with some 2,200 airmen while a total of over 5,000 units were introduced to the region.
The production run of UH-1's yielded about a dozen major variants, some with sub-variants to boot. The initial production variant became the HU-1A, utilizing the early-form designation system that eventually changed to UH-1A in 1962 and onwards. Production netted 182 UH-1A's. These systems were followed by four YUH-1B prototypes leading up to the UH-1B production model, essentially being "improved" A-models with revised rotors and other subtle outward changes. The UH-1C arrived with revised blades, improved rotor-head and new engines, built to a 767 example total.
The first major "departure" from the initial production models became the UH-1D, of which some 2,008 examples were produced. These were based on the Bell Model 205 which itself was nothing more than a long-fuselage version of the Bell Model 204 while increasing rotor diameter, range and power from its Lycoming T53-L-9A, T53-L-11D 1,100shp engines or the Allied Signal Engines (ASE) T53-L-13B turboshafts of 1,400shp. The sliding double-windowed side doors were also made larger in this version. The US Army pressed these into service as troop transports beginning in 1963 to replace their aging Sikorsky CH-34 Chocktaw fleet while many were eventually upgraded to the upcoming UH-1H standard. UH-1D's could be crewed by 2 personnel while supplying room for up to 13 troops.
UH-1D (as well as UH-1H) production models were armed with the standard door-mounted M23 M60D 7.62mm machine guns on M23 subsystems to provide cover fire along the flanks. Early production UH-1D's featured the XM3 23-tube rocket launchers, the M5 40mm grenade launcher and the M6 quad M60C machine gun mounts for the gunship role. The large cabin space of D-models eventually set them apart as primary utility helicopters while the smaller UH-1B and UH-1C's were therefore utilized as primarily as gunships.
The UH-1E became a USMC product based on the UH-1B and UH-1C models. 192 of this type were built. Likewise, the UH-1F fell into service with the USAF and were similarly based on the UH-1B and UH-1C models. F-models were further differentiated by their use of General Electric T-58-GE-3 turboshaft engines of 1,325shp. 120 total examples of these Hueys were produced.
The UH-1H was a high quantity version, essentially similar to the UH-1D and built in some 5,435 total examples, and featured an improved Lycoming T-53-L-13B turboshaft engine of 1,400shp. H-models had the same basic armament suite of the UH-1D's - the standard M23 M60D 7.62mm door mounted machine guns. Likewise, passenger seating equaled space for 13 combat-ready troops. Additional changes included a revised two-bladed semi-rigid all metal main rotor system and rigid delta hinged two-bladed tail rotor system. H-models became the model of quantity of the entire Hueys production line. Production spanned from 1965 through 1986 and was also undertaken under license in Turkey and Taiwan. A specialized H-model was developed in the six-man (2 pilots and 4 gunners) UH-1H "Nighthawk" featuring a Zenon searchlight system coupled to an M134 7.62mm minigun armament for night work. Additional armaments included twin M60D 7.62mm machine guns and an M2HB 12.7mm heavy machine gun.
The USN utilized the purpose-built HH-1K (based on the Bell Model 204) for Search and Rescue duties. The UH-1M was a dedicated gunship model fitted with the Lycoming T-53-L-13 engine of 1,400shp.
The UH-1N was a somewhat vast departure from previous Huey offerings in that this model version sported twin turboshaft engines. These aircraft were built upon the Bell Model 212 design and also went under the name of "Twin Pac". The UH-1P was a UH-1F variant utilized by the USAF for use by the 20th Special Operations Squadron "Green Hornets". The UH-1V became a specialized US Army MedEvac model with room for six stretchers and one personnel while the UH-1Y appeared as a new Bell product intended to upgrade operators of their current UH-1N systems.
As of this writing, the USMC has begun deliveries (beginning early 2009) of what is expected to be 123 examples of the UH-1V "Venom" helicopter models. First fight of this variant was achieved on December 20th, 2001 and production now signals the new generation of Hueys. Despite maintaining a general external look to her previous incarnations, the Venom is an all-new modernized Huey complete with an all-composite four-blade main rotor, twin engine arrangement, four-blade tail rotor, FLIR, all-digital cockpit sporting multi-function displays and improvements over the base Huey's maximum speed, range and take-off weight. This modernization will no doubt extend the life of the Huey for some decades more.
The United States Army have already phased out their fleet of frontline UH-1's, having replaced them with the Sikorsky UH-60 Black Hawk series while still retaining some 700 Hueys in for a few years more. The USAF still utilize Hueys in limited utilitarian roles as needed but overall, the Sikorsky UH-60 series is poised to become the next workhorse of the American military.
Beyond Bell's localized production of its Huey line, the helicopter has undergone license-production in Italy through the Agusta-Bell banner, in Japan through the Fuji-Bell name, in Germany via Dornier Flugzeugwerke, and in Taiwan through AIDC. Total production to this date of the Huey in all forms and for all operators is estimated to be over 16,000 units. Operators range the world over - from Afghanistan to Zimbabwe - and quite possibly make the Bell UH-1 Huey the most successful helicopter line of all time. Major users of the Huey line have been the United States Army, Australian Army, Philippine Army and the Japanese Ground Self-Defense Force.