Design and Development
In March 1937, a design team headed by Donald Douglas, Jack Northrop and Ed Heinemann produced a proposal for a light bomber powered by a pair of 450 hp (336 kW) Pratt & Whitney R-985 Wasp Junior radial engines mounted on a high-mounted wing. It was estimated that it could carry a 1,000 lb (454 kg) bomb load at 250 mph (400 km/h). Reports of aircraft performance from the Spanish Civil War indicated that this design would be seriously underpowered, and it was subsequently cancelled.
In the autumn of the same year, the United States Army Air Corps issued its own specification for an attack aircraft. The Douglas team, now headed by Heinemann, took the Model 7A design, upgraded with 1,100 hp (820 kW) Pratt & Whitney R-1830 Twin Wasp engines, and submitted the design as the Model 7B. It faced competition from the North American NA-40, the Stearman X-100 and the Martin 167F. The Model 7B was maneuverable and fast, but did not attract any US orders.
The model did, however, attract the attention of a French Purchasing Commission visiting the USA. The Neutrality Act of 1935 at the time forbade the sale of arms, including aircraft, to any nation at war, and President Roosevelt had just issued a call both for its revision and a rearmament program for the Air Corps. Aided by the Treasury Department's Procurement Division (headed by retired Naval officers) and Secretary of the Treasury Henry Morgenthau, Jr., the French discreetly participated in the flight trials, so as not to attract criticism from American isolationists. The Air Corps, which controlled the aircraft's development but had been excluded from negotiations between the French, the Production Division, and the Navy's Bureau of Aeronautics, was directed by the White House on 19 January 1939 to release the DB-7 for assessment in contradiction of its own regulations. The "secret" was blown when the Model 7B crashed on 23 January while demonstrating single-engine performance. The French were still impressed enough to order 100 production aircraft, with the order increased to 270 when the war began. Sixteen of those had been ordered by Belgium for its Aviation Militaire.
Although not the fastest or longest-ranged in its class, the Douglas DB-7 series distinguished itself as a tough, dependable combat aircraft with an excellent reputation due to its speed and maneuverability. In a report to the British Aeroplane and Armament Experimental Establishment (AAEE) at RAF Boscombe Down, test pilots summed it up as "has no vices and is very easy to takeoff and land... The aeroplane represents a definite advantage in the design of flying controls... extremely pleasant to fly and manoeuvre." Ex-pilots often consider it their favorite aircraft of the war due to the ability to toss it around like a fighter. Its true impact was that the Douglas bomber/night fighter was extremely adaptable and found a role in every combat theater of the war and excelled as a true "pilot's aeroplane."
When DB-7 series production finally ended on 20 September 1944, a total of 7,098 had been built by Douglas and a further 380 by Boeing.
Read more about this topic: Douglas A-20 Havoc
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