|First flight||28 September 1912|
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.
After a number of indoor tests, the aircraft was demonstrated outdoors and made a number of free take-offs. One of these trials was witnessed by Prince Axel of Denmark. 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. Although a wind tunnel model was constructed, there's no evidence that anything more was studied.
- Crew: One pilot
- Main rotor diameter: 2× 7.47 m (24 ft 7 in)
- Main rotor area: 12.0 m2 (130 ft2)
- Powerplant: 1 × Custom-built radial engine, 27 kW (36 hp)
|Wikimedia Commons has media related to Ellehammer helicopter.|
- Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions. p. 348.
- Leishman, J. Gordon (2006). Principles of Helicopter Aerodynamics. Cambridge: Cambridge University Press. p. 8.
- Munson, Kenneth (1968). Helicopters and other Rotorcraft since 1907. London: Blandford Publishing.