Akaflieg Stuttgart fs29

The Akaflieg Stuttgart fs29 TF "Stadt Stuttgart" is a glider designed and built in Germany from 1972.
Development.
The fs29 was designed and built to research the telescopic variable span wing.
With the wing at full extension the fs29 could thermal successfully in very weak conditions and land safely in small spaces, conversely with the wing fully retracted the fs29 could cruise between lift at higher speeds, improving performance in distance/speed competitions, as well as perform aerobatics to higher load factors with faster control response.
Construction of the fs29 was as follows:-
Extension and retraction of the outer wings was made by a screw jacks and nuts operated by the pilot pumping a handle via two-way free-wheel mechanisms, toothed belts and torque shafts which pulled or pushed the outer wings over the inner wings as required. The gap between the inside of the outer wing and the skin of the inner wing could be as much as 3mm without causing excess drag or affecting the flying qualities.
The fs29 was demonstrated in flight at the 1996 ILA airshow at Berlin Tempelhof Airport, along with the Akaflieg Braunschweig SB-10 and SB-13.
The sole fs29 was damaged in an accident during the summer of 1997, but is being re-built; meanwhile the fs29 can be seen at the Deutsches Museum in Munich.