As you probably know, Armand Dufaux was a Swiss aviation pioneer who became famous for flying the length of Lake Geneva in 1910. He and his brother, Henri Dufaux, a Swiss painter, built a twin-rotor model helicopter in 1905.
However, if you look further into their design history, they also constructed two models of a tilt-rotor design back in 1900. I'm not sure if they constructed a manned prototype or not.
However, if you look further into their design history, they also constructed two models of a tilt-rotor design back in 1900. I'm not sure if they constructed a manned prototype or not.
