In the autumn of 1922, Dewoitine submitted to the CEDANA (Commission d'Examen des Appareils Nouveaux pour l'Aeronautique) a high-altitude version of the D 1 (which had then still to fly) designated D 8. One category of fighter in the 1921 C1 programme called for a speed of 240km/h at 7000m and a practical ceiling of at least 8500m. After discarding the proposal to equip the D 8 with a Rateau turbo-compressor, Dewoitine adopted the higher compression Hispano-Suiza 8Fe engine of 360hp. A larger wing of wood rather than metal construction was introduced and the prototype was rolled out in the late summer of 1923.
At Francazal, the D 8 attained an altitude of 2000m in 4.25 min, 3000m in 6.83 min, 4000m in 10.5 min and 5000m in 15.1 min. For publicity purposes this performance was attributed to the D 1 fighter. The C1 requirement for a high-altitude fighter having been abandoned, and, in June 1924, the D 8 was modified for an attempt on the world air speed record, fitted with a lightened version of the D 1 wing. On 23 December 1924, the D 8 established 100-, 200- and 500-km closed-circuit records while being flown by Marcel Doret, and, on 12 December, set a 1000km closed-circuit record of 221,775km/h.
Max take-off weight: 1100 kg / 2425 lb
Empty weight: 780 kg / 1720 lb
Wingspan: 12.80 m / 41 ft 12 in
Length: 7.50 m / 24 ft 7 in
Height: 2.75 m / 9 ft 0 in
Wing area: 25.00 sq.m / 269.10 sq ft
Max. speed: 245 km/h / 152 mph