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Prestwick Dragonfly
Role Human-powered aircraft
National origin United Kingdom
Manufacturer Prestwick Man Powered Aircraft Group
Number built 1

The Dragonfly was a human-powered aircraft, designed and built by the Prestwick Man Powered Aircraft Group, based at the Prestwick International Airport in South Ayrshire, Scotland. [1]

Design and development

The aircraft was developed with the specific goal of winning the £50,000 Kremer prize then on offer. [2] Its designer, Roger Hardy, previously had experience with three other HPAs; the SUMPAC, Jupiter, and the Mercury. [3]

An emphasis was placed on it being a practical, easily-built, machine, with the construction requiring a comparatively low amount of work hours. [2] [4] It was intended to fly outside of ground effect, reaching an altitude of 60 ft (18 m) in 5 minutes, at what was described as "a small but realistic rate of climb." [1] [3] If attempting the Kremer course, such altitude would permit greater room for manoeuvres without suffering from wing tip stalls. [4]

The Dragonfly was a wire-braced high-wing monoplane, with a pylon-mounted propeller, and had no unconventional features. The wing had an aspect ratio of 30, and a relatively high wing-loading. The wing could increase its dihedral under flight load, changing from 6° when static, to 10° in flight. Lateral control was achieved by differental ailerons. [1] The wing had a single wooden box-spar, with a secondary structure made from spruce, balsa and polystyrene. The fuselage was of the pod and boom type, a primary structure made using aluminium alloy, and a secondary structure of balsa. The empennage featured a small all-flying tailplane, or stabilator, and a large fin, half of was the rudder. The entire aircraft was covered in Melinex. The pilot was in a recumbent cycling position, and powered the plyon-mounted propeller. [1]

Construction began in February 1975, and was completed by July. Taxying trials took place in August 1975, however they revealed issues with the craft. It failed to achieve take-off due to the high thrust-line of the propeller and the small moment of the tail-plane. [5] During the following two months, changes made to the aircraft included the strengthening of the rear fuselage, increasing the moment arm of the tail-plane, and changing the pylon-mounted propeller from a pusher to a tractor configuration. [1] [6]

Jane's all the world's aircraft 1976-77 wrote that further flight tests may take place from the Spring of 1977 onward. [1] An article in the February 1977 issue AeroModeller stated that Ron Frost had taken over development of the aircraft. [5]

Specifications

Data from Jane's all the world's aircraft 1976-77 [1]

General characteristics

  • Crew: 1
  • Length: 24 ft 1.50 in (7.3533 m)
  • Wingspan: 80 ft (24 m)
  • Height: 9 ft 7 in (2.92 m) with propeller horiztonal
  • Wing area: 213.50 sq ft (19.835 m2)
  • Aspect ratio: 30
  • Airfoil: Wortmann FX63-137
  • Empty weight: 95 lb (43 kg)
  • Gross weight: 232 lb (105 kg)
  • Max takeoff weight: 252 lb (114 kg)
  • Propellers: 2-bladed fixed pitch, 9 ft (2.7 m) diameter

Performance

  • Maximum speed: 23 mph (37 km/h, 20 kn)
  • Cruise speed: 19 mph (31 km/h, 17 kn)
  • Stall speed: 16 mph (26 km/h, 14 kn)
  • Never exceed speed: 31 mph (50 km/h, 27 kn)
  • Wing loading: 1.18 lb/sq ft (5.8 kg/m2) at maximum take-off weight

See also

Aircraft of comparable role, configuration, and era

Related lists

References

  1. ^ a b c d e f g Taylor, John W. R., ed. (1976). Jane's all the world's aircraft 1976-77. London: Macdonald and Jane's Publishers Ltd. pp. 487–488. ISBN  0354005383. Retrieved April 23, 2023.
  2. ^ a b Hardy, R.J. (February 1975). The optimised man-powered aircraft. Proceedings of the Man-Powered Aircraft Group Symposium. London, UK.
  3. ^ a b Moulton, Ron (May 1975). "Progress with man powered flight". AeroModeller. Hemel Hempstead, Herts, UK: Model & Allied Publications Ltd. p. 294.
  4. ^ a b Reay, D.A. (1977). The history of man-powered flight. Oxford, England: Pergamon Press Ltd. pp. 298–299. ISBN  0080217389.
  5. ^ a b Moulton, Ron (February 1977). "Progress with Man Power". AeroModeller. Hemel Hempstead, Herts, UK: Model & Allied Publications Ltd. pp. 102–104.
  6. ^ Moulton, Ron (March 1976). "Man powered aircraft". AeroModeller. Hemel Hempstead, Herts, UK: Model & Allied Publications Ltd. pp. 144–145.
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