The History and Development of Bell Helicopters
The important point that one has to remember is that the development of the concept of helicopters was not started by Bell, or for that matter not even in America. The first attempts were in Europe and records say that the first attempt was made by Dr. Van Hecke who built a helicopter with 4 rotors in 1847 in Belgium. There are no records of many flights undertaken by it, and it is unlikely that it made any flights at all as the technology was undeveloped. The next important attempt was made in Italy 30 years later by Prof. Enrico Forlanini who demonstrated his model of a helicopter. This was a small machine weighing just 3.5 kilograms or 7.7 pounds and had coaxial rotors for developing power through a two cylinder steam engine. The takeoff was through the use of a spherical steam accumulator which built up pressures to the level of 10 atmospheres, or 10 times the pressure of air in the atmosphere. Then this was released and the craft rose to the level of 13 meters or 43 feet and remain airborne for about 20 seconds. (Rotary Wing Aviation) It is clear that the concept of a helicopter was in the minds of men for a long time, but no practical design was built to translate the dream into reality. Part of the reason
In the meantime, the Department of Defense has changed the designation to UH-1 when the first designation was for the new series of helicopters in DOD. The process of development was standard with larger engines and increased capacities. The usage of these machines are for many transport, airborne battlefield command and control, troop insertion or removal, coordination of fire support, medical evacuation, search and rescue, provision of armed escort or visual reconnaissance, and utility. (Bell 204 / 205 H-1 Iroquois 'Huey') The size of helicopters today is "41 feet 9 inches of 12.7 meters long, 14 feet 5 inches of 4.4 meters high, and with a rotor diameter of 48 feet of 14.6 meters. The weight is around 5,210 pounds or 2,363 kilograms empty, a maximum speed of 127 miles per hour or 204 kilometers per hour and a range of 276 nautical miles or 511 kilometers". (Bell UH-1 Huey) It can be seen clearly that there has been a lot of development over a period of time. In spite of all developments Viet Cong chose to hold their positions than run away when they found out that helos could be brought down with small arms fire. The model of H-21 was found to be particularly vulnerable. Taking the case of just one battle at Ap bac near Saigon in January 1963, four H-21 and one armed Huey were lost. These made the US Air Force change tactics and remain mobile in air, and during the course of the war 2,500 Huey were lost in Vietnam, half due to combat and the others in operational accidents. The point to be noted now is that Bell and its licensed firms like Augusta in Italy, which has now been bought over by Bell had built over 15,000 Huey. These were the most numerous helicopter ever built and probably the largest number that have been built after 1945 for all transport aircraft except the Soviet Antonov AN-2. (Bell UH-1 Huey) It is clear that one of the main reasons for success that the product was that it was in time for the requirements of the country. The professors who had developed the autogiros also developed the first helicopter in 1937 after conducting research. This machine was called FW61. The machine was based on the fuselage of a small biplane trainer with two outriggers which supported the contra-rotating rotors. There was also a cut down set of propellers mounted in front of the radial engines and being used only for cooling. The machine became very famous and was demonstrated in the Deutschlandhalle stadium in Berlin. The machine used to make descents without power and this was first made by this machine in 1937. At the same time, there were also developments of helicopters in Britain and that flew in 1938. This was called Weir W5 and had been designed by CG Pullin. The machine had a total weight of only 860 pounds and could reach maximum speeds of 70 miles per hour as seen in the 80 hours of test flying. This led it to being developed further, and the new model was called W6, and this also became the first two-seater helicopter in the world. (Helicopter History: The Early Years) To achieve this, the rotors were first mounted on separate outriggers or co-axially on the same drive shaft to take care of this effect. The progress in this direction was first made in 1897 by a German designer named B. R. Beenan. He started the use of a tail rotor which was different from the other rotors and this was used to counteract the turning effect or torque reaction. This design also had further developments like variable pitch control of the main and tail rotor blades along with ability of tilting the rotor. (Helicopter History: The Early Years) One can see clearly that progress in the designing of helicopters had started and designers had started feeling that there were future possibilities in the concept in future.
Some common words found in the essay are:
Helicopter History, Wing Aviation, Senor Juan, H-1 Iroquois, Services Canada, Enrico Forlanini, Department Defense, Specs Stage, H-13 Model, Helicopter Model, helicopter history, bell helicopter, bell helicopters, model 47, bell 47, rotary wing, commercial success, rotary wing aviation, wing aviation, 205 h-1 iroquois, development helicopters, / 205 h-1, bell 204, 204 / 205, bell 204 /,
Approximate Word count = 3906
Approximate Pages = 16 (250 words per page double spaced)
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