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Douglas Mixmaster

The Douglas XB-42 Mixmaster was an experimental bomber aircraft that was specifically designed to attain a high-top speed.

The aircraft’s unconventional approach involved the installation of two engines within the fuselage, which drove a pair of contra-rotating propellers mounted at the tail in a pusher configuration.

This design ensured that the wing and fuselage remained clean and free of drag-inducing protrusions.

Although two prototype aircraft were constructed, the conclusion of World War II resulted in a shift in priorities.

Additionally, the advent of the jet engine provided an alternative means of achieving high speed.

The XB-42 was originally developed as a private enterprise, with an unsolicited proposal being submitted to the United States Army Air Forces in May of 1943.

This resulted in the USAAF awarding a contract for two prototypes and one static test airframe, as they saw the potential for a bomber with the range of the Boeing B-29 Superfortress, but without its size or cost.

The aircraft was equipped with a pair of Allison V-1710-125 liquid-cooled V-12 engines, which were located behind the crew’s cabin and each drove one of the twin propellers.

The wing leading edge contained air intakes, while the landing gear was tricycle and a full, four-surface cruciform tail was installed, with a ventral fin/rudder unit preventing the coaxial propellers from striking the ground.

The pilot and co-pilot were situated under twin bubble canopies, while the bombardier was located in the extreme front behind a plexiglass nose.

Defensive armament consisted of two 0.50 in (12.7 mm) machine guns on each side of the trailing edge of the wing, which could be retracted into the wing when not in use.

These guns were aimed by the co-pilot through a sighting station at the rear of his cockpit, with a limited field of fire (25 degrees left/right and +20/-15 in elevation) to the rear.

However, due to the aircraft’s high speed, it was deemed unlikely that intercepting fighters would attack from any other angle.

Two additional guns were installed to fire directly forward.

Initially ordered as an attack aircraft (XA-42) in the summer of 1943, this variant would have been armed with 16 machine guns or a 75 mm (2.95 in) cannon and two machine guns.
53 ft 8 in (16.36 m)
70 ft 6 in (21.49 m)
18 ft 10 in (5.74 m)
Wing area
555 sq ft (51.6 m2)
Empty weight
20,888 lb (9,475 kg)
Max take-off weight
35,702 lb (16,194 kg)
2 × Allison V-1710-125 liquid-cooled V12 engines,
1,800 hp (1,300 kW) each
Maximum speed
410 mph (660 km/h, 360 kn) at 23,440 feet (7,140 m)
1,800 mi (2,900 km, 1,600 nmi)
Ferry range
5,400 mi (8,700 km, 4,700 nmi)
Service ceiling
29,400 ft (9,000 m)
0.16 hp/lb
6 × .50 in (12.7 mm) machine guns,

Two in twin rear-firing turrets.


Two fixed forward-firing.
8,000 pounds (3,600 kg) in internal.

Charles Daniels Photo Collection
The National Museum of the U.S. Air Force
McDonnell Douglas aircraft since 1920: Volume I-René J Francillon.

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