George de Bothezat

George de Bothezat (Gheorghe Botezatu, Георгий Александрович Ботезат, June 7, 1882 – February 1, 1940) was a Russian American engineer, businessman and pioneer of helicopter flight.

Biography
George Bothezat was born into a family of Bessarabian landlords in 1882 in Saint Petersburg, Russia. After graduating from a school located in Chisinau in 1902, he attended the Electrotechnical Institute in Belgium between 1905 and 1907, graduated from Kharkiv Polytechnical in 1908, continued his graduate studies in the Göttingen and Berlin and received his Ph.D. from the University of Paris for a study of aircraft stability. In 1911, he joined the faculty of Saint Petersburg Polytechnical University and continued theoretical studies of flight along with Stephen Timoshenko, Alexey Lebedev and Alexander Vanderfleet. His scientific interests gradually moved from general aerodynamic theory to applied studies of propellers.

In 1914, Bothezat accepted the position of director at the Polytechnical Institute in Novocherkassk, but the outbreak of World War I compelled him to return to Saint Petersburg and join the Technical Commission of the Imperial Russian Air Force. In 1915, Bothezat published standard bombing tables for the Air Forces, and in 1916 he was appointed chief of the Main Airfield in Saint Petersburg – Russia's first flight research facility. He managed the design team of the DEKA aircraft plant in Saint Petersburg, and was credited with the design of a single-engined aircraft that was tested in 1917.

In May 1918, with his homeland in the throes of the Russian Revolution, Bothezat fled from the Bolsheviks to the United States, where he styled himself De Bothezat. In June 1918, he was hired by the National Advisory Committee for Aeronautics. He lectured at the Massachusetts Institute of Technology and the Columbia University.

In 1921 the US Army Air Service hired de Bothezat to build a prototype helicopter. The quadrotor helicopter, known simply as the de Bothezat helicopter, was built by de Bothezat and Ivan Jerome in the hangars of Wright Field near Dayton, Ohio. The first flight turned out to be surprisingly successful for a machine that had been built without prototyping. In 1922, their "flying octopus" flew many times, although slowly and at low altitudes. In fact, its horizontal motion was induced by wind more than by the pilot's controls. The Army, now more interested in autogyros, cancelled the underperforming project.

De Bothezat returned to New York City and started his own business in making industrial fans, which was incorporated in 1926 as de Bothezat Impeller Company, Inc. The company's axial fans were installed on US Navy cruisers, but this was as far as de Bothezat would go in dealing with the government. He continued publishing essays on topics ranging from flight dynamics to economics of the Great Depression. His 1936 book Back to Newton attacked Albert Einstein's theory of relativity and the whole world of contemporary academics "who are utterly unable to acquaint themselves with the subject". Einstein personally refuted de Bothezat's claim at a public lecture given by de Bothezat at Princeton on 15 June 1935. He worked for the film industry, designing mechanical special effects props for Dudley Murphy's The Love of Sunya (1927).

De Bothezat returned to helicopters in 1938. His new company was incorporated as Air-Screw Research Syndicate and later renamed Helicopter Corporation of America. Boris Sergievsky, former test pilot of Sikorsky Aircraft, became de Bothezat's partner and test pilot. De Bothezat's new helicopter was a coaxial design, with the engine mounted between two rotors. The first machine, SV-2, was built and tested on Roosevelt Field in 1938; after the tests de Bothezat and Sergievsky rebuilt it into a heavier SV-5. However de Bothezat, who was also designing a one-man "personal helicopter" for infantrymen, died before the SV-5 could be properly tested. The new machine proved to be unstable and crashed; Sergievsky escaped unharmed.

Selected works

 * The general theory of blade screws (1920). National Advisory Committee for Aeronautics.
 * General theory of the steady motion of an airplane (1921). National Advisory Committee for Aeronautics.
 * The Depression, Its Real Causes and the Remedy (1933). Economic Security League.