SN 1
Type
Single seat experimental
Engine
1 BMW X
Dimensions
Length 6,20 m, span 8,80 m
Weights
flying weight 470 kg
Performance
Max. speed 150 km/h
Type
Werk.Nr
Registration
History
   
D-2257
Shown at the DELA 1932
Designed by Prof. Schmeidler and Dip.-Ing. Gerhard Neumann as a high wing monoplane for  low speed flying. The chord could be changed in mid section, enlarged
PROF. DR. SCHMEIDLER,
of the College of Engineering at Breslau, in Germany, has developed a wing, the area and profile of which are variable in flight to the extent of one-fifth of the full wing area. The manner in which the problem has been solved is very interesting. It is materially different to what has been done in this direction hitherto.
The invention was demonstrated on a monoplane, the wing of which contained a trailing edge portion having the shape roughly of a right-angled triangle, the acute angle of which is pivoted inside the wing at the tip end,  while the side opposite is held in a guide on the cabin wall, or rather inside the central section of the wing, which covers the cabin. On its lower side this trailing edge of the wing is provided with a toothed rack, which engages  with a pinion on a shaft passing through the central mainwing section to the other wing, where it likewise carries a pinion similarly engaging with a rack on the other wing section. The pinion shaft also carries a chain sprocket, and a chain transmission leads to a sprocket by the side of the pilot's seat, where a handle with a pawl arrangement is provided. The handle is worked in pump-handle fashion, and by its means the trailing edge portions are
pushed out or pulled in. The retractable sections are so shaped as to form a continuation of the main wing profile so the latter assumes a different camber when the sections are pulled in.
The invention was demonstrated in flight, as also whenstarting and landing. With the wing sections drawn in, the starting distance was very materially increased (to the extent, it is asserted by the inventor, or 40 to 50 percent.). In flight the drawing in of the wing sections effected a very pronounced increase of speed.
Diagrammatic representation of the operating mechanism
of the Schmeidler variable wing. The camber as well as the area is altered.
THE SCHMEIDLER VARIABLE WING :
Diagrammatic Plan View of the arrangement of the wing. The trailing edge is pivoted at the outer end and housed in the main wing.
Increasing the Speed Range
German Plane with Variable Wing Area and Profile
By EDWIN P . A. HEINZE
FLIGHT, MAY 13, 1932