B
Gerhard Wilke
Wilke worked with the Flettner rotor in twenties . A biplane with the the lower wing changed to the Flettner concept but it stayed just as a project
A sound configuration is presented by Gerhard Wilke  This concept looks like a biplane in principle. Here, the lower rotating wing should be used only as high lift device for short take off and landing. In cruise flight, the cylinder would be streamlined by movable plates to reduce drag. At low speed, the rotors should be used to enhance the lift force. Their rotational speed should be independent from the speed of the aircraft engine, which should serve as driving mechanism for the rotor