The ubiquitous Bell Model 204 utility helicopter made its first flight in 1956. It was adopted by the US Army in 1959 as the UH-1 Iroquois. It is still in line to name the US Army helicopters after the Native American Indian tribes. This helicopter is unofficially known as the Huey. It was the first turbine-powered aircraft to serve with the US Army. It replaced Piasecki H-21 and Sikorsky CH-34 in the US Army service. Eventually than 11 000 of UH-1 series helicopters were built. In a modern form this utility helicopter continues to serve to this day.

The UH-1 was the most successful utility helicopter ever built, overtaking the Russian Mi-8/Mi-17. Improved and upgraded variants of the UH-1 remain in widespread use.

The UH-1 was the workhorse of the US Army in during Vietnam W4r. This transport helicopter was used for various purposes. Typical missions were transport of troops, fuel, ammunition and supplies, gunship mission, and medical evacuation mission. During that w4r, the UH-1 revolutionized w4rf4r3, adding a new dimensions to air mobility. A new “air cavalry” concept was pioneered. It enabled soldiers to move from one firefight to another by air, leapfrogging the enemy and seizing the advantage. Even battalion-sized units were moved from one battlefield to another. However thousands of these helicopters were lost to enemy small arms fire.

The UH-1 is operated by a crew of 3, including pilot, co-pilot and crew-chief/door gunner. The UH-1D could carry 10 passengers or 6 stretchers. It had internal payload capacity of around 1 500 kg.

The UH-1 could be armed with one or two door-mounted 7.62 mm machine guns. The Huey was the first helicopter to see a widespread use as a gunship. At the time it was the most suitable helicopter for this role. The UH-1 was outfitted with machine guns, grenade launcher and even pods with 70 mm unguided rockets and four side-mounted guns. It was used for ground attack and armed escort role. The UH-1s also flew hunter-killer teams with observation helicopters, such as OH-58A Kiowa and OH-6 Cayuse.

This helicopter has a straightforward design. The original UH-1A had a single Avco Lycoming T-53 turboshaft engine, developing 960 shp. However soon more powerful engines became standard. Later models even had two engines. Both rotors had two blades. This helicopter has simple, but tough, landing skits, rather than complex retractable undercarriage.

Since its introduction the original UH-1 has been constantly improved and upgraded. There were numerous variants of this helicopter, including specialized machines. It remains an important type. Major variants are listed below.

UH-1A was initial production model. Originally it was designated as HU-1A, but re-designated UH-1A in 1962. It was powered by a 960 shp engine. Only 182 of these helicopters were built.

UH-1B was an upgraded version with various external and rotor improvements. Originally it was designated as UH-1B, but re-designated UH-1B in 1962. A total of 1 014 were built, plus 4 prototypes.

UH-1C is a dedicated gunship version, which evolved from the UH-1B. It had improved and more powerful engine developing 1 100 shp, larger rotor blades and modified rotor head for better performance. A total of 767 were built.

UH-1D. The Bell Model 205 was developed from the previous Model 204. It was a long-fuselage version with greater lifting capacity. Also it had a larger loading door. This helicopter was specially designed as a troop carrier. It first flew in 1961 and was adopted in 1963. The UH-1D began to arrive in Vietnam in 1965. A total of 2 008 of these helicopters were built. Eventually many were upgraded to the UH-1H standard.

AH-1 Cobra is the first dedicated attack helicopter. Its company designation is Model 209. It is also unofficially called as Huey Cobra. It was specially designed as an armed escort for troop carrying helicopters to meet a US Army requirement. Eventually this machine was a turning point in the development of helicopter technology and its application. It first flew in 1965. Deliveries commenced to the US Army in 1968. Even though little in the appearance of the Cobra shows off its roots. Engine and transmission were borrowed from UH-1D. The Cobra has a narrow fuselage and was specially designed to be as small target as possible to enemy ground fire.

UH-1E was a version of the UH-1C for the US Marine Corps. This helicopter was fitted with different avioncs and equipment. A total of 192 were built. UH-1F was a version of the UH-1C for the US Air Force. It was powered by General Electric T58-GE-3 engine, developing 1 325 shp. A total of 120 were built.

UH-1H was an improved US Army version, fitted with a Lycoming T53-L-13 engine, developing 1 400 shp. The utility helicopter was first flown in 1961. It was adopted as the UH-1H in 1966 (?). It was the most numerous version of the UH-1. Bell built 3 573 UH-1Hs for US forces and a further 1 317 were exported.

UH-1J is an improved Japanese version of the UH-1H. It is powered by Allison T53-L-703 engine, developing 1 800 shp. This helicopter also has a vibration-reduction system, infrared countermeasures, improved cockpit and some other improvements. It was license-produced in Japan by Fuji Heavy Industries.

UH-1N. The twin-engined Bell Model 212 was a significant development of the Model 205. It was powered by Pratt & Whitney Canada T400-CP-400 engines. The Bell Model 212 was adopted as the UH-1N. This helicopter is also called the Twin Huey. It was also license-produced by the Agusta-Bell. Deliveries commenced in 1970. This helicopter remains in widespread military service, most significantly with the US Marine Corps, to which the first machine was delivered in 1971. The US Air Force still uses the UH-1N fleet to protect intercontinental ballistic missiles and transport the US government and security forces. In addition, Bell and Agusta-Bell produce the Model 412 and AB 412 respectively, based on the Model 212, but with a four-bladed main rotor as standard. This aircraft has also found many military customers.

UH-1P was an UH-1F variant for the US Air Force special operations use. This helicopter was used solely by the USAF 20th Special Operations Squadron, known as Green Hornets.UH-1Y Venom is a rebuilt, redesigned and deeply upgraded version, used by the US Marine Corps. It is also called the Super Huey. Upgrade program was launched by the US Government in 1996 for bringing well qualified and combat proven helicopters to modern standards. The UH-1W Venom was developed alongside the AH-1Z Viper attack helicopter under the same program and shared common systems, engines and components. Improvements include uprated General Electric T700-GE-401C engines. These have a continuous output of 1 550 shp, but can develop 1 800 shp for 2.5 minutes.

These drive a new four-bladed main rotor system.The upgraded cockpit havs modern mission and ωɛλρσɳs computers, advanced communication and navigation equipment. The UH-1Y also received thermal imaging system in the FLIR under the nose, plus greatly improved self-protection systems. This helicopter has significantly increased speed, maneuverability, range, crashworthiness and lift capability, plus enhanced battlefield survivability. The useful load increased to slightly over 3 000 kg. First UH-1Y helicopters were delivered to the US Marine Corps in 2008 and full-rate production commenced in 2009. The US Marine Corps planed to obtain 160 of these helicopters until 2016. Initially it was planned that the older UH-1N airframes will be remanufactured to the UH-1Y standard. However later it was announced, that these will be newly-built machines.