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HISTORY OF THE HELICOPTER

One important characteristic of the history of vertical flight is the pervasive human interest
in the subject; inventors in many countries took up the challenge over the years.
The history of vertical flight began at least as early as about 400 a.C; there are historical
references to a Chinese kite that used a rotary wing as a source of lift. During the latter
part of the 15th century, Leonardo da Vinci made drawings of a helicopter that used a
spiral airscrew to obtain lift.

In France, Argentine inventor Raúl Pateras Pescara, who designed several helicopters in
the 1920s and ’30s that applied cyclic pitch control and, if the engine failed, rotor
autorotation, set a straight-line distance record on April 18, 1924, of 736 meters.

In Spain in the previous year, on January 9, 1923, Juan de la Cierva made the first
successful flight of an autogiro. An autogiro operates on a different principle than a
helicopter. Ironically, however, the technology of the rotor head and rotor blade
developed for the autogiro contributed importantly to the development of the successful
helicopter, which in time made the autogiro obsolete.

In the United States, after many successes with commercial flying boats, Igor
Sikorsky turned his attention to helicopters once again, he made a successful series of
test flights of his VS-300 in 1939–41. However, it also clearly showed the difficulties that
all subsequent helicopters would experience in the development process. For many
years, compared with conventional aircraft, helicopters were underpowered, difficult to
control, and subject to much higher dynamic stresses that caused material and
equipment failures. Yet the VS-300 led to a long line of Sikorsky helicopters, and it
influenced their development in several countries, including France, England, Germany,
and Japan.