Hartman Ikarus

The Ikarus was a human-powered ornithopter, designed by the sculptor and designer Emiel Hartman in the late 1950s.[1]

Ikarus
Role Human-powered aircraft
National origin United Kingdom
Designer Emiel Hartman
Built by Don Campbell
First flight 1959
Number built 1

Development

The ornithopter was a high-wing monoplane, with the pilot seated in a recumbent position. Its construction followed conventional glider practice of the time. The fuselage had a bulkhead construction, covered in thin plywood. The wings featured a torsion-box spar and leading edge arrangement, and were also made from thin plywood. A series of 30 'feathers', covered in madapollam cotton were attached aft of the spar, and were able to individually bend and twist as the wings were flapped.[2] The wings could be flapped through an arc of 30° dihedral to 10° anhedral, via a parallelogram structure which the pilot could operate using leg and arm power, with a rowing-like action. Bungee cords were integrated into the drive mechanism, to absorb and release energy as needed.[1][3] It was expected that the wings would flap at 30 beats per minute.[2] The craft featured a conventional empennage, with the pilot being able to control the elevator and rudder. There was no provision for lateral control. There was a tricycle undercarriage, with a steerable nosewheel.[1][2]

Design of the ornithopter began in February 1958, with Hartman seeking advice from a number of aviation organisations and consultants. Construction commenced in August, with the work being undertaken by the glider constructor Don Campbell of Hungerford, Berkshire.[2] The craft was completed by August 1959, with initial taxi trials being undertaken in September. In mid-October, the Ikarus was delivered to Cranfield Airport for further tests.[2]

Testing

Flight testing commenced on Sunday, 1 November 1959, with Hartman acting as pilot. Non-flapping flights were made, towed behind an automobile. During a subsequent towed flight, conducted on Wednesday, 4 November, at an altitude of 30 ft (9.1 m), Hartman experienced control difficulties due to a 7 mph (11 km/h) crosswind, landed heavily and incurred a ground loop, which damaged the port wing.[4][5]

In 1964, it was reported that the Ikarus was still in storage at the College of Aeronautics, at Cranfield, with no further flight attempts having been made.[4] The project (including design, drawing, and construction) was said to have involved 4,624 hours worth of work, and to have cost £2,450.[2]

Patents
  • GB patent 885273, Emile Hartman, "Improvements relating to ornithopters", issued 1961-12-20
  • GB patent 851352, Emile Hartman, "Improvements relating to ornithopters", issued 1960-10-12

Specifications

Data from Sailplane and Gliding[2]

General characteristics

  • Crew: 1
  • Wingspan: 36 ft (11 m)
  • Wing area: 144 sq ft (13.4 m2)
  • Aspect ratio: 9
  • Airfoil: Göttingen 535
  • Empty weight: 282 lb (128 kg)
  • Powerplant: 1 × Pilot leg and arm power

Performance

  • Cruise speed: 25 mph (40 km/h, 22 kn)

See also

Aircraft of comparable role, configuration, and era

Related lists

References
  1. Reay, D.A. (1977). The history of man-powered flight. Oxford, England: Pergamon Press Ltd. pp. 181–182. ISBN 0080217389.
  2. Campbell, Don (December 1959). "The Hartman Ornithopter". Sailplane and Gliding. Vol. X, no. 6. London, UK: The British Gliding Association. pp. 333–334, back cover.
  3. Karl Herzog (1964). Laidlaw-Dickson, D.J.; Moulton, R.G. (eds.). Translated by Dick Hirdes. "Flapping wing flight in nature and science". Aeronautical Annual 1964-65. Watford, Herts, UK: Model Aeronautical Press: 44–57.
  4. R.G. Moulton (1964). Laidlaw-Dickson, D.J.; Moulton, R.G. (eds.). "Muscle Power". Aeronautical Annual 1964-65. Watford, Herts, UK: Model Aeronautical Press: 58–63, 137.
  5. Smith, Maurice A., ed. (13 November 1959). "Sport and Business". Flight. Vol. 76, no. 2644. London, UK: Iliffe & Sons Ltd. p. 557.

Bibliography
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