10/31/2011. Flown in June 1924, the D.9 was derived from the D.1 for participation in the 1923 C1 (fighter) program and was powered by a 420 hp Gnome & Rhône 9Ab (license-built Bristol Jupiter IV) nine-cylinder air-cooled radial engine. Early in the flight test program, the standard 215.28 sq.ft (20.00 sq.m) D.1 wing was supplanted by a new wing of 26.9 sq.ft (2.5 sq.m) greater area, and a six-month delay in the commencement of evaluation of the contenders in the 1923 C1 program provided Dewoitine with the opportunity to increase wing area by yet a further 26.9 sq.ft (2.5 sq.m).

Armament consisted of two fuselage-mounted 0.303 in (7.7 mm) Vickers guns and two Dame Model 19 guns of 0.295 in (7.5 mm) caliber mounted on the wing centre section. The D.9, placed sixth among the contenders, was destroyed on October 15, 1925. Nonetheless, it emulated the export success of the D.1. License-built in Italy by Ansaldo as the A.C.3, the D 9 was supplied to Yugoslavia (six) and Belgium (one) in 1925, and the components of three others were delivered in 1927 to the EKW (Eidgenössische Konstruktionswerkstätte, Federal Constructions Workshop, also known as K+W) at Thun, Switserland, for assembly, with delivery to the Fliegertruppe in 1928.

Span: 41 ft 11.875 in (12.80 m)
Length: 23 ft 10.67 in (7.30 m)
Height: 9 ft 7.33 in (2.93 m)
Wing area: 269.1 sq.ft (25.00 sq.m)
Empty weight: 2,083 lb (945 kg)
Loaded weight: 2,939 lb (1,333 kg)
Max speed: 152 mph (244 kmh) at sea level
Max speed: 142 mph (229 kmh) at 16,405 ft (5,000 m)
Climb: 1,713 ft (522 m)/min
Range: 248 mls (400 km)