The XT3D torpedo bomber (BuNo 8730) was first flown in 1931, it has been described as a large and ugly aircraft. Of metal construction with a fabric covering the XT3D had folding wings and an arrestor hook for carrier operation. With a fixed tailwheel landing gear and powered by a Pratt & Whitney R-1690 Hornet radial engine, the XT3D had three open cockpits, forward for the gunner/bomb-aimer, centre for the pilot, rear for another gunner.
The XT3D failed to meet the Navy's requirements and after tests was returned to Douglas. It was modified with a more powerful Pratt & Whitney XR-1830-54 radial, and wheel fairings and the two rear cockpits were enclosed. Re-designated XT3D-2, it still failed to pass Navy trials and was not ordered into production. The prototype was used by the Navy for the next ten years for general purpose use until it was relegated as an instructional airframe in 1941.