It was designed by Douglas on behalf of the United States Navy, which sought a carrier-capable strategic bomber. During July 1949, Douglas was awarded the contract to produce its design, having bested eight other aircraft companies' submissions. Unlike rival designs, which had aimed for a maximum take-off weight, the Skywarrior was developed for a take-off weight, facilitating its use from the navy's existing s. Large portions of the aircraft were produced by the Westinghouse Electric Corporation, including its early Westinghouse J40 turbojet engines, which failed to meet promises and were replaced by the rival Pratt & Whitney J57 engine by mid-1953. On 28 October 1952, the prototype "XA3D-1" performed the type's maiden flight.