Based on experiments with models, Jacob Ellehammer constructed a full-size machine equipped with two contra-rotating discs, each of which was fitted with six vanes around its circumference.

The same engine that drove the rotors also powered a propeller mounted tractor-wise to the aircraft's frame.

Experiments with the helicopter continued until September 1916, when it tipped over during take-off, destroying its rotors.

A famous photo shows it hovering in 1914, though there is no evidence that it was successful in achieving translational flight.

Ellehammer later studied a disc-rotor configuration - a compound helicopter with coaxial blades that extended from the hub for hover, and retracted for high speed vertical flight.