I will bring you only some of History that I think it is useful for you to know about how the helicopter was developed. They were so many great people contributed to this technologies but some of them were succeed and some were not. We all thanks to those people which make today happen.

It was during 1909 that Igor Sikorsky Build his first machine in Russia in common many earier designed. But this first Sikorsky helicopter never left the ground, and a second which followed in 1910 ,he did not succeeded at this time so, he stopped and turn to fixed wing aircraft until 1930 .

  VS-300: In 1939, Sikorsky and a team of his engineers desinged the VS-300. The VS stood for VoughtSikorsky and the 300 indicated that it was Sikorsky's third helicopter design.Vs300 had a75 hp Franklin 4cylinder engine. The basic structure was the heavygauge welded steel tubes. It had no covering at all and no instruments.It had three bladed main rotor and the anti-torque rotor at the rear.

  The R-4: In 1941, Sikorsky and Gluharaff designed the production model of VS300 and desinated VS316A . It was the bigger a bigger machine with an enclosed cabin and side by side seating and dual controls for two men crew 175 hp engine, a larger 36 ft (10.97 m.) rotor.The VS316A known by military designation XR-4 and YR4A.

  The R-5 and S-51: In 1943,Sikosky was working on all metal designated VS327 to meet requirement of USAAF known as XR5S and YR5A. It was better and bigger than R4.
In 1946, the first civilian type helicopter,S51 (four seats) was the first helicopter to be licenced by the US Civil Aviation Administration for commercial operation.

  The S-55: In 1949, Sikorsky S-55 was located 600hp engine in the nose. For the first time, a helicopter was capable of lifting a heavy load up to ten soldiers,in addition to its two men crew.

  Fa-61: Germany stepped to the front in helicopter development with the Focke Achgelis Fa-61, which it has two three-bladed rotor mounted on outriggers and power by a 160 hp radial engine. The Fa-61 had controllable cyclic pitch and set many of records .
In 1938, Fa-61 made an altitude flight of 11,243 feet and cross-country of 143 miles.In this year, the german aviator Hanna Reitsch became the world's first woman helicopter pilot by flying the Fa-61 in the Deustchland-halle in Berlin. Germany continued its helicopter development during world war two and was the first to place the helicopter,Flettner Kolibri, into mass production.

 Cierva C30A : An Autogiro, in 1923 , Juan de la Cierva , a young engineer made the first successful flight of an autogiro. An autogiro operates on a different principle than a helicopter.That was the rotor of autogiro was not driven by the engine but rotated itself as the aircraft was drawn along by its propeller. Autogiro used extreamely short take-off and landing but it could not move sideways or hover in still air like a helicopter. The Autogiro's rotor is designed so that a blade set at a low positive angle of pitch will rotate automatically as long as an airstream is kept flowing through the rotor .However, the technology of the rotor head and the rotor blade developed for autogiro contributed importantly to the development of the successful of helicopter.

  Bell Model 30 :Bell Aircraft Corporation was formed in 1935 but it was until 1943 that the first Bell Helicopter Model 30 was successful flown. Several version of model 30 were built . Model 47 , built in 1945 and was granted the world's first commercial helicopter licence. The Bell 47 developed into the most successful light - utility helicopters ever. A total of morethan 6,000 variants were built until the production was stopped in 1973.