L.Opdyke French Aeroplanes Before the Great War (Schiffer)
Papin et Rouilly
In 1911 A Papin and D Rouilly patented their Gyroptere and built it in 1913 and 1914. The first (if unsuccessful) air-jet helicopter, their machine was based on the sycamore seed, which falls, turning, a one-bladed rotor. Slightly to one side of the axis of rotation was mounted a rotary motor on its back, which drove a turbine to draw air in and force it out the length of the single long airfoil-shaped blade, exiting through a nozzle at the trailing edge of the tip. The blade would turn rapidly, and the gyroscopic force of the motor would lift the blade into a positive angle of attack. Centered on the axis of rotation was the drum in which the pilot sat; it was mounted on ball-bearings and was centered against 4 horizontal rollers. The pilot controlled a separate swiveling air-duct to keep his drum-shaped seat from moving with the blade, and to provide forward thrust in flight.
Beautifully built, with compound curves and a smooth sweep of its blade, the Gyroptere was not a success. It was tested in 1915 on Lake Cercey, near Pouilly-en-Auxois in eastern France. Lead was fitted to improve the balance and increase the rpm; on 31 March it achieved 47 rpm, but was wildly out of balance, and the blade smashed repeatedly into the water, damaging itself and shaking up the pilot. The last photographs show its wing still intact.
(Length: 14 m; empty weight: 380 kg)