Cramlington Cramcraft
| Cramcraft | |
|---|---|
| Role | Basic training glider |
| National origin | United Kingdom |
| Manufacturer | Cramlington Aircraft Co., Northumberland |
| First flight | c.5 October 1930 |
| Number built | c.3 |
The Cramlington Cramcraft was a simple, single-seat, primary training glider, designed in the United Kingdom in 1930. About three were built.
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)
References
- ^ a b c d e f g h i Ellison, Norman (1971). British Gliders and Sailplanes. London: A & C Black Ltd. pp. 102, 245. ISBN 978-0-7136-1189-2.
- ^ a b "A North Country glider" (PDF). Sailplane and Glider. 1 (5): 36. 3 October 1930. Archived from the original (PDF) on 30 September 2011.
- ^ a b "The Latest Cramcraft" (PDF). Sailplane and Glider. 2 (1): 11. 17 July 1931. Archived from the original (PDF) on 30 September 2011.
- ^ "Cramlington advertisement" (PDF). Sailplane and Glider. 1 (7): 51. 3 October 1930. Archived from the original (PDF) on 30 September 2011.
- ^ "More news about the Cramcraft" (PDF). Sailplane and Glider. 1 (7): 54. 17 October 1930. Archived from the original (PDF) on 30 September 2011.