Engineering Analysis of the 1907 Cornu Helicopter

Abstract

Paul Cornu (1881–1944), a Frenchman from Lisieux, along with his father Jules and brother Jacques, pioneered the development of three rotating-wing aircraft concepts from 1906 to 1908. Their work encompassed the development of flying models, attempts at flying a larger, piloted helicopter concept, and the design of a hybrid or convertiplane concept. Their aeronautical patents included a method of flight control using differentially activated shuttered louvers, as well as cyclic blade pitch using a form of swashplate mechanism. Paul Cornu claimed that he first flew their twin-rotor helicopter concept for the first time in November of 1907. However, the engineering analysis of his concepts conducted in this paper shows that Paul Cornu’s claim to successful piloted flight with a helicopter, free of the ground and under positive control, is extremely dubious. Although the Cornus were apparently successful in building and flying models of a helicopter concept, what they lacked was the necessary understanding of rotor aerodynamics, helicopter performance, and effective methods of flight control to scale their flying models to the size needed to carry a pilot free of the ground. This paper describes a chronology and a critical engineering analysis of the Cornus’ helicopter concepts, from their flying model in 1906, to the more well-known 1907 piloted helicopter, and finally to their “Helicoplane” hybrid concept of 1908.