Cramlington Cramcraft

The Cramlington Cramcraft was a simple, single-seat, primary training glider, designed in the United Kingdom in 1930. About three were built.

Cramcraft
Role Basic training glider
National origin United Kingdom
Manufacturer Cramlington Aircraft Co., Northumberland
First flight c.5 October 1930
Number built c.3
Unit cost
£55 in 1930

Design and development

The Cramcraft was a single-seat primary glider trainer, aimed at newcomers to the sport and designed with simplicity, robustness and low cost in mind rather than aerodynamic performance.[1] It was a wooden aircraft with wings of rectangular planform built around two box spars which, like the ribs, were made from spruce and plywood.[2] Ailerons reached to the wing tips but no airbrakes were fitted.[1] The tail surfaces were carried on a narrow, flat boom formed by two parallel beams from the wing leading edge, braced together and fabric covered.[2] Both the boom-mounted tailplane and elevators it carried were rectangular in plan, though the latter had a cutout for rudder movement and extended beyond the tailplane.[1] The rudder was mounted on a very narrow fin and initially extended further below the boom than above[1] but was later modified so that little projected below and the upper profile became more rounded.[3]

Initially the pilot's seat was mounted well below the wing leading edge on the narrow edge of a board or plank.[1][4] The under edge of this board was shaped to curve up forwards and served as a skid. The board was fixed to the wing spars by two pairs of parallel V-form lift struts, the angle between them being unusually small.[1] This arrangement left the pilot completely exposed and a later version placed him in a short nacelle.[3] Both wings and tail were further wire braced, with lift wires from the fuselage and above from a pair of inverted V-struts mounted on the two boom beams.[1]

Operational history

The first serious testing was on 5 October 1930. Several pilots flew the Cramcraft, though no flights of more than 30 seconds were achieved that day.[5] It is probable that three Cramcrafts were built, at least one of them flying with the Newcastle gliding club and another with the Sunderland club, both near to Cramlington.[1]

Specifications (early version)

Data from Ellison[1]

General characteristics

  • Crew: 1
  • Length: 17 ft 0 in (5.18 m)
  • Wingspan: 33 ft 6 in (10.21 m)
  • Wing area: 151 sq ft (14.0 m2)
  • Aspect ratio: 7.6
  • Empty weight: 140 lb (64 kg)


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References
  1. Ellison, Norman (1971). British Gliders and Sailplanes. London: A & C Black Ltd. pp. 102, 245. ISBN 978-0-7136-1189-2.
  2. "A North Country glider" (PDF). Sailplane and Glider. 1 (5): 36. 3 October 1930. Archived from the original (PDF) on 30 September 2011.
  3. "The Latest Cramcraft" (PDF). Sailplane and Glider. 2 (1): 11. 17 July 1931. Archived from the original (PDF) on 30 September 2011.
  4. "Cramlington advertisement" (PDF). Sailplane and Glider. 1 (7): 51. 3 October 1930. Archived from the original (PDF) on 30 September 2011.
  5. "More news about the Cramcraft" (PDF). Sailplane and Glider. 1 (7): 54. 17 October 1930. Archived from the original (PDF) on 30 September 2011.
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