The first Paul Cornu helicopter was built in 1906 in Lisieux. The machine weighed 13.75 kg and its Buchet engine delivered a full 2 hp and drove two 2,25 m rotors. Horizontal propulsion was achieved by inclined surfaces that were placed in the downwash from the lifting propellers.

Paul Cornu's unmanned model helicopter

 

 

It reached an altitude of three metres and made flights of up to 20 metres.