08/15/2008. During the course of 1937, the Service Technique de l'Aéronautique (STA) prepared a requirement for a T3 (Triplace de Travail) aircraft, a light three-seat twin intended to perform a variety of roles ranging from tactical reconnaissance and army co-operation to light-bombing and crew training. In the same time, due to the nationalization of the French aviation industry, Dewoitine had been amalgamated into the SNCAM (Société Nationale de Constructions Aéronautiques du Midi).

To meet the STA requirement, the SNCAM began the design of the D.700 T3 in January 1938 and first metal was cut in May 1938, but shortly thereafter the STA altered the requirement stipulating the observer to be housed in the nose of the aircraft rather than in proposed ventral gondola. The aircraft was redesigned and the power plants were switched from the intended two 220 hp Renault 6Q six-cylinder air-cooled inverted in-line engines to two 500 hp Renault 12R 00/01 twelve-cylinder air-cooled inverted V-engines, and the aircraft was redesignated D.720 T3.

Immediately aft of the co-pilot's seat was a mounting for an oblique F30 of F50 or ventral F70 camera. Alternatively, a Type F and two Type J racks for a total of twenty 22 lb (10 kg) bombs could be installed in this position. A single fixed forward-firing 0.3 in (7.5 mm) MAC 34 machine gun was to be installed for the pilot, while the radio-operator/gunner was to have two of these machine guns in a manually operated SAMMA B33 dorsal turret, and a single-one on a flexible mounting firing through a hatch in the floor.

The pictures prototype was first flown at Toulouse-Francazals by Marcel Doret on July 10, 1939, and after the completion of the manufacturer's flight test program, the aircraft was flown to the Centre d'Essais du Matériel Aérien (CEMA) at Orléans-Bricy on September 25, 1939, but by this time deliveries of the Potez 630 variants had begun to the Armée de l'Air, and as the crew training variant of this, the Potez 63.16 T3, was nearing completion, further development of the D.720 T3 seemed pointless, and the project was abandoned.