Every Time I Hear A Helicopter Overhead I Still Think Of VietNam Shirt
The next 25 years were characterized by two main trends in vertical flight. One was the wide spread of minor successes with helicopters; the second was the appearance and apparent success of the autogiro (also spelled autogyro).The helicopter saw incremental success in many countries, and the following short review will highlight only those whose contributions were ultimately found in successfully developed helicopters. In 1912 the Danish inventor Jacob Ellehammer made short hops in a helicopter that featured contrarotating rotors and cyclic pitch control, the latter an important insight into the problem of control. On December 18, 1922, a complex helicopter designed by George de Bothezat for the U.S. Army Air Force lifted off the ground for slightly less than two minutes, under minimum control. 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 metres (2,415 feet). That same year in France on May 4, Étienne Oehmichen established a distance record for helicopters by flying a circle of a kilometre’s length.
Every Time I Hear A Helicopter Overhead I Still Think Of VietNam Shirt
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. Its rotor is not powered but obtains lift by its mechanical rotation as the autogiro moves forward through the air. It has the advantage of a relatively short takeoff and a near vertical descent, and the subsequent success of Cierva’s autogiros and those of his competitors seemed to cast a pall on the future of helicopter development. Autogiros were rapidly improved and were manufactured in several countries, seeming to fill such a useful niche that they temporarily overshadowed the 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.
