The Arado SD II was a single-seat sesquiplane fighter produced alongside the similar SD III and that became the basis for the Arado Ar 64.
The SD II looked very similar to the SD I, and like the earlier aircraft had a welded steel fuselage, wooden wings and was covered with a mix of plywood and fabric. It was a rather larger aircraft than the SD I (nearly six feet wider and over two feet longer), and also much heavier, with nearly twice the empty weight and a 50% increase in maximum take-off weight. As a result, despite the increase in engine power from 425hp on the SD I to 530hp on the SD II, the new aircraft was significantly slower than the SD I.
The SD II was powered by a licence-built Jupiter VI radial engine with reduction gearing and had a three-blade propeller. One prototype was built, making its maiden flight in 1929. The SD III was developed at the same time, and differed mainly in the nature of its engine. After these two prototypes work moved onto the Arado Ar 64.
Engine: Gnome-Rhône Jupiter VI radial engine
Wing span: 32ft 5 3/4in
Length: 24ft 3 3/4in
Empty Weight: 3,186lb
Maximum take-off Weight: 3,902lb
Max Speed: 146mph at 16,405ft