Arado SD I
Single seat fighter
1 Bristol  Jupiter
Length 6.75 m, height 2.90  m, span 8.40 m, wingarea 16.8 m2
Empty 850 kg, flying weight 1230 kg, wing loading 73.2 kg/m2
Max. speed 275 km/h, service ceiling 8000 m, climb to 1000 m 1.6 min.
Two fixed forward firing MG 08/15 7.92mm machine guns
Tested at Rechlin. Crashed on the 11th of october 1927 on the 21st flight, pilot Dr. Theodor Bienen was killed
Of relatively advanced concept and the first fighter to be built by the Arado Handelsgesellschaft of Warnemunde, the SD I was designed by Ing Walter Rethel and owed much to experience gained with Fokker. Of comparatively small overall dimensions, the SD I was a single-seat sesquiplane of mixed construction. The fuselage was of welded steel tubing with light alloy skinning to the cockpit firewall and fabric aft. The wings were wooden with plywood skinning, featuring ailerons in the upper wing only, the cellule having V-type interplane struts and lacking conventional flying wires. The SD I was powered by a 425hp nine-cylinder Gnome-Rhone Jupiter air-cooled radial and armament comprised two synchronised 7.9mm 08/15 machine guns. The first fighter design to be the subject of a contract from the Reichswehrministerium, the SD I was built clandestinely, the first of two prototypes flying on 11 October 1927. Evaluation revealed poor low-speed handling characteristics, and, as it was considered to be structurally unsound by the RWM, its development was discontinued in favour of an entirely new design, the SD.II.