Helicopter also known as chopper, is a multipurpose flying machine which has two blades on the top, which, by its rotational movement help the helicopter to lift itself in the air. A helicopter has a different structure, size and working principle than the airplane. The major difference is that of the absence of wings as it uses blades on the top instead.
The amazing features of a helicopter consist of the three way vision that a pilot gets. Apart from this, the pilot can fly the helicopter anywhere and it can stay stable in the air at a low height as well. Flying a helicopter is a difficult task because the pilot has to use both his two arms and two legs and also has to take care of the three dimensions.
Helicopters were first built and developed during the earlier days of the history of flight itself, though the production was limited. But, only in 1942, a helicopter designed by Igor Sikorsky was accepted widely after 131 aircrafts were built. Though old designs used multiple main rotors, the single main rotor with anti torque tail configuration design was the one that came to be recognized as the present day helicopter.
In July of 1754, Mikhail Lomonosov, a Russian writer, scientist and polymath displayed a small coaxial rotor in front of the Academy of Sciences, Russia. A spring was installed in to provide power supply by and this method was suggested by him which can lift instruments which are meteorological. In the year 1783, Christian de Launoy, along with Bienvenu, his mechanic, prepared a model which had two rotors; counter-rotating. They had used flight feathers of turkey as rotor blades. They demonstrated it to the Academy of Sciences, France in 1784. In 1861, a French inventor Gustave de Ponton d'Amécourt coined the word "helicopter". He had prepared a small model of helicopter which was steam powered, but as it was made out of aluminum, it was too heavy to fly. Nevertheless D'Amecourt's contribution survived to describe the vertical style of flight he had already envisioned.
Other inventors also made use of Steam power. Enrico Forlanini flew an unmanned helicopter in 1878 which used a steam engine as its power supply. James Gordon Bennett, Jr. gave Thomas Edison US $1,000 in 1885 for experiments in the field of developing aviation system. Edison made a helicopter which had an internal combustion engine but the engine got exploded and burnt a worker badly. Edison sent the report that a motor was needed which produced power at the scale of 1 horsepower for every 3 to 4 pounds. In 1901, Ján Bahýľ, for his helicopter model, adopted Edison’s internal combustion engine and his helicopter flied 0.5 meters high. On May 5th, 1905, Bahyl’s helicopter flew for more than 1,500 meters at the altitude of 4 meters. In 1908, Thomas Edison got his helicopter design patented which used a gasoline engine which had box kites connected to a mast by cables to be used as a rotor, but it could not fly.
Raúl Pateras Pescara demonstrated one of the initial successful cyclic pitch applications in 1920s. Contra-rotating, coaxial biplane rotors were used to cyclically increase and decrease the lift. The rotor hub could be tilted some degrees forward, which helped the helicopter to move forward without using another propeller to push it. Pescara also demonstrated the autorotation principle by which a helicopter can safely land if the engine fails. In January of 1924, a helicopter numbered 3 made by Pescara flew for ten minutes.
In 1930, Corradino D'Ascanio, an Italian engineer built a coaxial helicopter, a D'AT3. His machine was relatively large which had two counter-rotating rotors which were double-bladed. Auxiliary wings or servo-tabs were used to achieve control and this concept that was later used for other designers like Kaman and Bleeker for their helicopters. Three small propellers were used for extra pitch, yaw and roll of control.
