The Douglas XB-42 was the last twin-engine propeller driven bomber tested by the Army Air Forces. Initially ordered as attack aircraft (XA-42) in the summer of 1943, the first of two aircraft built flew on May 6, 1944, after being redesignated XB-42. The medium bomber design featured two Allison V-12 engines housed within the fuselage driving dual contra-rotating pusher propellers aft of the empennage. Each engine used five P-39 propeller drive shafts connected to a complex gearbox arrangement to turn the propellers. The purpose of the design was to test a long-range medium bomber that could fly as far as the B-29 but required less resources to build, operate and maintain. Like the other bombers ordered as insurance against a failure of the B-29 program, the XB-42 was never ordered in quantity.
The Mixmaster carried only three crewmen -- a pilot, copilot who doubled as a gunner, and bombardier. Because the design had a 410 mph maximum speed, defensive armament was relatively light -- only six .50-cal. machine guns. One gun was mounted in a fixed position on either side of the forward fuselage for head-on defense, and the other four guns were mounted in pairs on the trailing edge of the wing between the flaps and ailerons. These guns were flex-mounted for rearward defense and could be controlled and fired by the copilot-gunner who faced rearward during defensive operations.
The first XB-42 was later modified by adding a small nacelle-mounted Westinghouse jet engine to each wing. This aircraft was redesignated XB-42A.
Medium bomber with pusher props
TECHNICAL NOTES: Armament: Six .50-cal. machine guns and 8,000 lbs. of bombs Engine: Two Allison V-1710-125 V-12 engines of 1,800 hp each Maximum speed: 410 mph. at 23,500 ft. Cruising speed: Approx. 310 mph Range: 1,840 miles; 5400 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: 35,702 lbs. (maximum gross weight) Crew: Three (pilot, copilot/gunner, bombardier) Serial numbers: 43-50224 and 43-50225