French engineer who designed and built the first helicopter to perform a manned free flight.

Cornu's twin-rotor craft, powered by a 24-horsepower engine, flew briefly on Nov. 13, 1907, at Coquainvilliers, near Lisieux. Previously, another French helicopter, the Bréguet-Richet I, had risen under its own power but had been held in position by men standing on the ground. Though historically important, Cornu's design proved impractical and soon was abandoned.