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 a higher compression Hispano-Suiza engine, the 8Fe with a nominal rating of 360hp. A larger wing of wooden 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 erroneously attributed contemporaneously to the D 1 fighter. The C1 requirement for a high-altitude fighter had meanwhile been abandoned, and, in June 1924, the D 8 was modified for an attempt on the world air speed record, being 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.