Douglas DB-7 (DB-7B3) twin-engine medium army bomber/heavy ground-attack aircraft, 1939 series.
An all-metal, three- or four-seat cantilever monoplane with retractable nose landing gear.
Jack Northrop, the famous American aircraft designer, started to develop this airplane as early as 1936, on his own personal initiative. When, in 1937, the United States Army Air Corps command formulated its requirements for a next-generation ground-attack aircraft/bomber, the draft design of the Model 7A multi-purpose aircraft (which would combine the functions of a light bomber, a ground-attack aircraft, and a scout) was already ready
In the meantime, the small Northrop Aviation Corporation was taken over by the Douglas Aircraft Company, which made it one of its branches. Since USAAC leaders had not made their final choice about their main bomber, Douglas Aircraft continued working on the aircraft, despite having no guarantee of its profitability. The first Model 7B prototype got off the ground for the first time on October 26, 1938.
The French Purchasing Commission took an interest in the new aircraft. After they learned of the prototype machine, French representatives placed an order for a total of 100 planes in February 1939. The Model 7B prototype aircraft was altered at the customer's request: the modified plane, designated the DB-7 (Douglas Bomber 7), made its first flight on August 17, 1939. The first production bomber was given to the French in October 1939.
The production DB-7 was equipped with 1,000 hp Pratt & Whitney R-1830-SC3-G fourteen-cylinder, double-row, radial air-cooled engines with Hamilton Standard Hydromatic 23E50 three-bladed automatic variable-pitch metal propellers.
The plane's defensive armament consisted of six 7.5 mm Chatellerault MAC 1934 machine guns of French manufacture. Four of these belt-fed machine guns, with 500 rounds each, were located in the nose section on each side of the navigator's glazed cockpit. One machine gun was mounted in the radio operator/gunner's cockpit in the rear upper gun position, and another one in the lower hatch. Both machine guns had 500 rounds each (5 pan magazines with 100 rounds).
The DB-7 had an enlarged bomb bay, with its payload capacity increased to 800 kg.
The plane had unusual landing gear for its time: the gear had three wheels, including a nosewheel.
The American aircraft were designated DB-7B3 (B3 meaning "three-seat bomber") by the French Air Force. In the summer of 1940, DB-7s participated in combat operations in Southern France, where they suffered serious losses assaulting German tank columns without fighter cover. Afterwards, the planes were in service with the aviation forces of the Vichy puppet government until November 1942, when they were used to strike the British-American landing forces in Algeria.