Having studied and tested ideas for torque-free helicopter, Josef Wagner formed Wagner Helicopter-Technik, Friedrichshafen, 1961. Early helicopters had coaxial rotors driven respectively by crankshaft and crankcase of engine. Later versions, called Sky-Trac, had conventional drive. Intended production vehicle, roadable 4-wheel, 4-seat Aerocar, completed 1968 but got no further.

Read 121 times