The Douglas XB-42A was a modification of the first XB-42 (S/N 43-50224). Two Westinghouse jet engines were added to the wing mounted in small nacelles. These auxiliary engines provided a total of 3,200 pounds of thrust and increased the top speed of the aircraft to almost 490 mph. The aircraft modification was done primarily for test purposes and all defensive armament was removed. To compensate for the increased fuel consumption caused by the jets, additional fuel cells were installed bringing the maximum range to 4750 miles -- about 650 miles less than the original XB-42.
As a follow-on project, Douglas built a pure jet aircraft based on the XB-42 design. This aircraft was designated XB-43 and was the first all-jet bomber tested by the Army Air Forces.
XB-42 modified with two jet engines
TECHNICAL NOTES: Armament: 8,000 lbs. of bombs Engine: Two Allison V-1710-133 V-12 engines of 1,800 hp each and two Westinghouse 19B-2 turbojets of 1,600 lbs. thrust each Maximum speed: 488 mph at 14,000 ft. Cruising speed: 250 mph Range: 4750 miles maximum ferry range Service ceiling: 29,400 ft. Span: 70 ft. 6 in. Length: 53 ft. 7 in. Height: 20 ft. 9 in. Weight: 44,900 lbs. (maximum gross weight) Crew: Three (pilot, copilot, bombardier) Serial number: 43-50224