Douglas XB-42 Mixmaster
XB-42 in flight
Description
Role	Attack bomber
Crew	Three
First flight	May 6, 1944
Manufacturer	Douglas
Dimensions
Length	53 ft 8 in	16.4 m
Wingspan	70 ft 6 in	21.5 m
Height	18 ft 10 in	5.7 m
Wing area	555 ft²	51.6 m²
Weights
Empty	20,888 lb	9,475 kg
Loaded	33,208 lb	15,063 kg
Maximum takeoff	35,702 lb	16,194 kg
Powerplant
Engines	2 × Allison V-1710-125 liquid-cooled V-12 engines
Power	1800 hp (each)	1,340 kW
Performance
Maximum speed	410 mph	660 km/h
Combat range	1800 miles	2,900 km
Ferry range	5400 miles	8,700 km
Service ceiling	29,400 ft	8,960 m
Rate of climb	ft/min	m/min
Avionics
Avionics
Armament
Guns	4 × 0.5 in (12.7 mm) machine guns in wing trailing edge turrets
Bombs	4 × 2000 lb (900 kg) bombs

The Douglas XB-42 Mixmaster was an experimental bomber aircraft, designed for a high top speed. The unconventional approach was to mount the two engines within the fuselage driving a pair of contra-rotating propellers mounted at the tail, leaving the wing and fuselage clean and free of aerodynamics-reducing protrusions. Two prototype aircraft were built, but the end of World War II changed priorities, and the advent of the jet engine gave an alternative way toward achieving high speed.

Developed initially as a private venture, an unsolicited proposal was presented to the United States Army Air Force in May 1943. This resulted in an Air Force contract for two prototypes, the Air Force seeing an intriguing possibility of finding a bomber capable of the B-29 Superfortress' range without its size or cost.

The aircraft mounted a pair of Allison V-1710-125 liquid-cooled V-12 engines behind the crew's cabin, each driving one of the twin propellors. Air intakes were in the wing leading edge. The undercarriage was tricycle, and there was a long fin under the tail to prevent the propeller from striking the ground. The pilot and co-pilot sat under twin bubble canopies, and the bombardier sat in the extreme front behind a glass nose. Defensive armament was two 0.50" machine guns in turrets in the trailing edge of the wing, which retracted into the wing when not in use. These guns could only cover the rearward direction, but with the plane's high speed it was thought unlikely that intercepting fighters would be attacking from any other angle.

The first XB-42 prototype flew on May 6, 1944. Performance was excellent, being basically as described in the original proposal; as fast or faster than the De Havilland Mosquito but with twice the bombload and defensive armament. The twin bubble canopies proved a bad idea, and the aircraft suffered from some instability, vibrations and poor engine cooling - all problems that could probably have been dealt with.

The end of World War II, though, allowed the Air Force to consider possibilities in a little more leisure, and it was decided to wait for the development of better jet bombers rather than continue with the B-42 program.

One of the XB-42 aircraft had been destroyed in a crash, but the other was used in flight test programs, including fitting uprated engines and underwing turbojets, making it the XB-42A. In this configuration, it reached 488 mph (785 km/h). Damaged in a hard landing in 1947 after 22 flights, it was repaired but never flew again.

The prototype was struck off charge in 1949 and was given to the National Air and Space Museum, in whose care it remains although it has never been placed on display.

External links

• USAF Museum: XB-42 and XB-42A.