J.Davilla, A.Soltan French Aircraft of the First World War (Flying Machines)

Papin-Rouilly Helicopter

  The helicopter designed by Papin and Rouilly featured a single hollow wooden blade and a fan acting as a counterweight. It was powered by an 80-hp Le Rhone rotary engine. The pilot was in a nacelle located between the blade and counterweight. The engine was started by a pulley system. The pilot operated the machine by three foot pedals as follows: one pedal opened the valve to admit air to the hollow blade, where it was ejected into a nozzle placed 90 degrees to the blade. A second pedal engaged or disengaged the engine. The third pedal allowed air into a rod, providing control of pitch and yaw. The escaping air left the blade at a speed of 328 feet per second. The blade was to turn at 60 revolutions per minute but managed only 47 during testing. The helicopter weighed close to 600 kg, considerably more than the 400 kg originally planned.
  The construction of a prototype was started in February of 1914 and completed in June. It was stored in a hanger next to Lake Cercey, close to Pouilly-en-Axois where the tests were to take place. The onset of war in August deterred any tests until the winter of 1914-15 when permission to proceed was given by the authorities.
  A test was carried out on 31 March 1915 on Lake Cercey. The helicopter seemed to break from the water, but became unstable during flight because the center of gravity had been miscalculated.
  A military commission observing the test determined that such a machine could not become operational, and halted further evaluation. The machine remained at the lake until sold for scrap wood in 1919.