Helicopter engineer and inventor. Born in Petrograd, Russia in 1882, De Bothezat attended the Technological Institute, Kharkow, Russia, 1902-1905; graduated with distinction from the Liege Electronic Institute of Belgium, 1907; did post-graduate work at Gt̲tingen Universitat and the University of Berlin (Sc.D, 1911). From 1912-1917 he was a college professor of aviation engineering and related fields. In 1918 he came to the United States as a lecturer and scientist. He served as a scientific expert for the National Advisory Committee for Aeronautics, Washington, D. C., 1918-1921. From June 1921 to May 1923, De Bothezat was Acting Chief of the Special Research Section, Engineering Division, McCook Field, Dayton, Ohio. Under contract to the United States Government, he built the "De Bothezat Helicopter," one of the first helicopters in the history of aeronautics to actually perform sustained men-carrying flights. He was assigned to the area of basic research to develop ideas and principles of aerodynamics for the Engineering Division, McCook Field, Dayton, Ohio, 1923-1925. He organized and headed two firms involved in manufacturing helicopters: first, the De Bothezat Impeller Company in New York, N.Y., 1925-1935; second, the Helicopter Corporation of America, which was begun in 1936. He died in 1940.