Designed and built to meet a US Navy requirement for a three-seat torpedo-bomber, the Douglas XT3D-1 prototype was first flown in early 1931. A biplane, basically of metal construction with fabric covering, the XT3D-1 incorporated folding wings and arrester gear for carrier-based operations, had fixed tailwheel landing gear, and was powered initially by a Pratt & Whitney S2B1-C Hornet radial piston engine. Accommodation was provided for a crew of three in open cockpits, a bomb-aimer/gunner forward, the pilot in the centre cockpit, just aft of the wing trailing edge, and a second gunner to his rear.
Failing to meet requirements in its initial service trials, the XT3D-1 was returned to Douglas for modification, gaining a more powerful 597kW Pratt & Whitney XR-1830-54 radial engine, wheel fairings for the main units and an enclosed canopy for the two rearmost cockpits. Redesignated XT3D-2, it was returned for further service testing but again failed to attract a production order. It was flown by the US Navy for about 10 years for general-purpose duties before being relegated for use as an instructional airframe in 1941.
Engine: 2 x Pratt & Whitney S2B1-G Hornet, 429kW
Max take-off weight: 3564 kg / 7857 lb
Empty weight: 1922 kg / 4237 lb
Wingspan: 15.24 m / 50 ft 0 in
Length: 10.79 m / 35 ft 5 in
Height: 4.03 m / 13 ft 3 in
Wing area: 57.97 sq.m / 623.98 sq ft
Max. speed: 206 km/h / 128 mph
Ceiling: 4265 m / 14000 ft
Range: 893 km / 555 miles
Armament: 2 x 7.62mm guns, 832kg of bombs