From the 20 contender firms, it was Bell that presented a design more adjusted to the requirements with its Bell model 204 and in 1955 the US Army requested the construction of 3 prototypes for evaluation under designation “XH-40“. The first of them made its maiden flight on October 22, 1956 and carried an 825 hp Lycoming YT53-L-1 turboshaft engine, (reduced to 700 hp), which made it the first turbine-powered helicopter used by the US Army.In 1957 the other two requested prototypes were delivered, to be followed by 6 helicopters designated as YH-40 for service tests. These 6 helicopters had a fuselage elongated by 30.5 cm and were ordered before even the first prototype had flown, which shows the confidence in the new aircraft. Finally, in March 1960 a first batch of 100 units was ordered officially designated “HU-1A Iroquois“, in honor of the Native Americans. The nickname “Huey” came from the English pronunciation of “HU” and became so popular that it was used even by the Military, ignoring the official name. In September 1962 the name changed to UH-1, but they remained known as Huey.The UH-1A is made of light alloy and its fuselage is of the semi-monocoque type with tubular landing skids. It has two rotors, the main one with two blades, as well as the tail one, which produce a characteristic sound known as “Huey thump”. Although the installation of a rotor with only two blades had enormous advantages in terms of saving storage space, it produced much more vibration, with consequent problems of material fatigue. Both rotors were driven by the main transmission, which reduced the engine’s output to 325 r.p.m. for the main rotor and at about 1,900 r.p.m. for the tail rotor in order to achieve the necessary effectiveness.(Swedish UH-1B image). The first UH-1A variant had the Lycoming T53-L-1 engine, which was found to be lacking in power, although it delivered continuous 770 hp. This model entered service in 1959 and had capacity for two crew members and six passengers or two stretchers and a medical assistant. To fulfill the request for a more powerful variant, Bell introduced the HU-1B, with a new 960 hp Lycoming T53-L-5 engine and a more spacious cabin, with space for two crew members and seven passengers or four stretchers and a medical assistant. This new variant entered service in 1961. Both designations were changed in 1962 to UH-1A and UH-1B respectively.In 1965 the UH-1C variant replaced the UH-1B in production, which reached 766 units. This new aircraft had a new 1,100 hp Lycoming T53-L-11 engine, installed to make up for the lack of power detected when the helicopter had to carry suspended loads. The rotor was also new and larger, which improved its maneuverability and speed, and the fuel capacity was also increased to 920 liters. Due to the larger size of the main rotor, the tail boom had to be changed and larger synchronized elevators had to be added among other modifications. The UH-1C entered service at the end of 1966 and with the new improvements the payload grew to 2,120 kg. Later the UH-1C engine was incorporated into all UH-1B fleet.In addition to these 3 main variants, others such as the UH-1E (on the image) were built for the US Marines (192 units). This variant was of all-aluminum construction with a rescue crane, rotor brake and special avionics. Also for the Marines 20 TH-1E training with dual control were delivered. 120 UH-1F were built to be used to support intercontinental ballistic missile (ICBM) sites as well as 26 training TH-1F. Both “F” models carried a more powerful 1,290 hp GE T58-GE-3 engine and larger rotors. The US Navy received 27 search and rescue HH-1K, similar to the UH-1E but with 1,490 hp Lycoming T53-L-13 engines and improved avionics. Lastly, 90 TH-1L Seawolf training helicopters and 8 UH-1L general utility helicopters were built, which were the UH-1E variant with a Lycoming T53-L-13 engine installed. The US Army received three UH-1M helicopters for evaluation. These units had a low intensity TV equipment installed.The first units to have the UH-1A were the famous 101st Airborne Division and the 82nd Airborne Division. In 1962 the US Army decided that the new helicopter should be sent immediately to Vietnam, where it arrived from the 57th Medical Detachment in March 1962. With the passage of time the Huey would become the representative symbol of the Vietnam War, and even today it continues to be. The missions performed were very varied and ranged from medical evacuation to ground attack, but the arrival of the most modern and powerful B-205 (UH-1D) progressively relegated it. The armament used by the early Hueys consisted mainly of 7.62mm machine guns and 70mm unguided rocket launchers.(Spanish Navy’s AB-204 AS image). The Spanish Navy acquired four AB-204 AS in October 1964 from the Italian company Agusta, which manufactured them under license. This variant was specific for anti-submarine missions, so it came with complete navigation equipment, doppler, radio altimeter and an ASE stabilizer that regulated an automatic verticality retention system. It also carried an immersion sonar and hooks for the transport and launch of two torpedoes or depth charges. They were the first helicopters of the Spanish Navy to have turbine engines, which led to the reconditioning of the maintenance facilities as well as the personnel assigned to these tasks.(Spanish Navy’s AB-204 AS image). The four AB-204 AS arrived in Spain in May 1965, receiving license plates Z.8-1 to Z.8-4 and numbers 003-1 to 003-4. Its radio callsign was “Bravo” and the first two helicopters entered service in June 1965, while the other two did in January and August 1966 respectively. They were a great qualitative leap for the ASW capacity of the Navy, since although they were light helicopters, thanks to their modern equipment they could operate both day and night and in any weather condition.(Spanish Navy’s AB-204 AS image). All Spanish AB-204 AS were framed in the 3rd Aircraft Squadron of the Navy, carrying out ASW missions until 1974. From this year onwards they were relieved of these missions by the newer and more powerful AB-212 ASW, remaining in service to carry out transport and rescue missions. All anti-submarine equipment was dismantled, leaving the crane on the right side for rescue tasks. The four were withdrawn from service between October 1978 and September 1979, after having made 11,622 flight hours, transferring the last 3 to the Army to serve as training for ground personnel and as spare parts for helicopters of the same type in service with its Air Force of the Army (FAMET).(Japanese Fuji-Bell 204B-2 image). The success of the UH-1 Huey was immediate and many countries showed interest in acquiring it. The Italian firm Agusta built under license the model UH-1B under designation Agusta-Bell AB-204. In other hand, the Japanese Fuji company also manufactured the UH-1B under license. The helicopter was known as Fuji-Bell 204B-2 “Hi’yodori” (a type of finch bird). This model had more powerful engine and a driving tail rotor and was assigned to the Japanese Army or JGSDF. Despite the numerous B-204 (UH-1A) delivered, the early appearance of the model B-205 (UH-1D), much more efficient, makes the figures of the first Huey pale in comparison, but it can be said, that this It was the model that spread the massive use of the helicopter throughout the world.
