The Slingsby T.37 Skylark 1 was a small low-cost
sailplane
A glider or sailplane is a type of glider aircraft used in the leisure activity and sport of gliding (also called soaring). This unpowered aircraft can use naturally occurring currents of rising air in the atmosphere to gain altitude. Sailplan ...
built during 1952-3 at Kirbymoorside,
Yorkshire
Yorkshire ( ) is an area of Northern England which was History of Yorkshire, historically a county. Despite no longer being used for administration, Yorkshire retains a strong regional identity. The county was named after its county town, the ...
by Slingsby Sailplanes.
Design and development
Fred Slingsby wanted to take a larger slice of the glider market with a small, low-cost sailplane with better than average performance. The key to this ethos was that smaller aircraft used fewer materials,
and modern aerofoil sections could give much better performance. Slingsby appointed John Reussner as draughtsman and designer for the T.37 Skylark. The relatively new five-digit
NACA
The National Advisory Committee for Aeronautics (NACA) was a United States federal agency that was founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its ...
series of
aerofoil sections was chosen because they would give low drag over a wide airspeed range ("wide Drag Bucket"). To maintain
laminar flow
Laminar flow () is the property of fluid particles in fluid dynamics to follow smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral m ...
and gain the benefit of the NACA sections, it was necessary to build the wings very accurately and ensure that the surface remained true during the life of the aircraft. This was achieved by using the low-density but stiff
Gaboon
''Aucoumea klaineana'' (angouma, gaboon, or okoumé) is a tree in the family Burseraceae, native to equatorial west Africa in Gabon, the Republic of the Congo, and Río Muni. It is a large hardwood tree growing to tall, rarely larger, with ...
plywood
Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...
. The leading edge was fashioned from accurately-spindled hollow spruce members with rebates to accept the gaboon ply wing panels extending back to the rear spar, leaving only a small area to be covered with fabric. The fuselage was a simple structure built up from struts and covered with plywood back to the rear of the wing support pylon, and fabric covering over the rear fuselage. Ply-covered tail surfaces and fabric-covered control surfaces completed the airframe. Further weight and cost was saved by not fitting a landing wheel.
History
The Skylark was successful to a limited degree but it introduced Slingsby to new manufacturing techniques and the vagaries of laminar flow. As with modern gliders any reduction in laminar flow caused a disproportionate increase in drag, reinforcing the need for careful handling, cleaning and polishing, and avoiding rain while flying. Despite the promising performance of the T.37 Skylark the British gliding fraternity convinced Fred Slingsby to modify his thinking and produce gliders with lower wing loadings, through increased span and wing area.
Specifications
See also
Notes
External links
Sailplane Directory
{{Slingsby aircraft
1950s British sailplanes
Glider aircraft
Skylark
''Alauda'' is a genus of larks found across much of Europe, Asia and in the mountains of north Africa, and one of the species (the Raso lark) endemic to the islet of Raso in the Cape Verde Islands
Cape Verde or Cabo Verde, officially ...
Aircraft first flown in 1953
High-wing aircraft