Igor Sikorsky is considered to be the "father of helicopters" due to his major contributions that occurred between 1909 and 1944. His work began in 1909 when he created his first helicopter prototype that utilized a pair of rotors placed on the same axis that rotate in opposite directions; however, this model was unsuccessful. It wasn't until 1939 that Sikorsky made his first significant helicopter contribution. This was the year that he first tested his VS-300 helicopter, which was the first practical helicopter made in the U.S.  This was also the first helicopter in the world to perfect the single main rotor and tail rotor that is seen in most helicopters today.  By 1941, this helicopter was able to fly for slightly over 1 hour and achieved full cyclic-pitch. Sikorsky used his VS-300 design to help create the R-4 helicopter in 1942. By 1944, the R-4 became the first helicopter to ever be mass produced. The R-4 contained some similar properties as the VS-300 including a steel framework and fabric-covered fuselage. Some of the improvements found in the R-4 were a fully-enclosed cabin and dual controls for the two pilots. The invention of the R-4 was a very important step in accelerating the development of the modern helicopter. It also helped transform warfare and the notion of speed and movement as they were used by the United States and Great Britain during the end of World War II. 

Text Sources:

Bellis, M. (2019). History of the helicopter. Retrieved from https://www.thoughtco.com/history-of-the-helicopter-1991899.

Boyne, W. J. (2019). Helicopter. Retrieved from https://www.britannica.com/technology/helicopter.

Johnston, S. P. (2019). Igor Sikorsky. Retrieved from https://www.britannica.com/biography/Igor-Sikorsky. 

Sikorsky R-4. (n.d.). Retrieved from http://www.aviastar.org/helicopters_eng/sik_r-4.php. 

VS-300 Helicopter. (n.d.). Retrieved from https://sikorskyarchives.com/VS-300_Helicopter.php.

Image Source:

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