Ellehammer Helicopter

The Ellehammer helicopter was an otherwise-unnamed experimental aircraft built in Denmark in 1912. 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 pitch of these vanes could be varied in operation by the pilot, an early example of cyclic control. The same engine that drove the rotors also powered a propeller mounted tractor-wise to the aircraft's frame.