The Siemens-Schuckert Werke S.S.W. D VI was a parasol wing fighter that was due to replace the S.S.W. D IV biplane in production, but that appeared too late and didn’t undergo flight tests until 1919.
The parasol wing had a rather unusual design. It was thin in the middle, got thicker towards the mid-point on each side and then tapered away towards the tips. It was linked to the circular-section fuselage by a series of struts, and had balanced ailerons. The D VI was also unusual in having a jettisonable fuel tank under the fuselage.
The D VI was powered by the same Siemans-Halske Sh IIIa rotary engine as the S.S.W. D IV and the earlier D III, but the new configuration was more efficient, and it was nearly 20mph faster than the D IV, despite having the same engine and being about the same weight.
The D VI appeared too late to play any part in the First World War. Two prototypes were completed, with serial numbers 3054/17 and 3055/17 (despite being ordered in April 1918). The aircraft underwent flight trials in February-May 1919, the period before the terms of the German armistice were enforced rigorously. One of the two aircraft was destroyed during these trials while the second was apparently sabotaged by workers at S.S.W. who wanted to make sure it wouldn't be taken by the Allied Control Commission.
Engine: Siemans-Halske Sh IIIa rotary engine
Span: 30ft 8 7/8in
Length: 21ft 4in
Empty weight: 1,188lb
Loaded weight: 1,562lb
Maximum take-off weight:
Max speed: 137.5mph
Climb Rate: 16min to 19,680ft
Endurance: 2 hours