In 1879 Melikoff designed a model helicopter fitted with an airscrew having the shape of a double parabola to provide lift and also able to act as a parachute.

A three-bladed airscrew was to give the aircraft forward motion, and power was to be supplied by a turbine rotating under the action of a mixture of air and ether vapours.

P.Lambermont "Helicopters and Autogyros of the World", 1958