Douglas XB-42 Mixmaster

The XB-42 was developed initially as a private venture; an unsolicited proposal was presented to the United States Army Air Forces in May 1943. This resulted in an Air Force contract for two prototypes and one static test airframe, the USAAF seeing an intriguing possibility of finding a bomber capable of the Boeing B-29 Superfortress's 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 propellers. Air intakes were in the wing leading edge. The landing gear was tricycle and a full, four surface cruciform tail was fitted, whose ventral fin/rudder unit incorporated a tailwheel to prevent the coaxial propellers from striking the ground. The pilot and co-pilot sat under twin bubble canopies, and the bombardier sat in the extreme front behind a plexiglass nose.Winchester 2005, p. 27.

Defensive armament consisted of two 0.50 in (12.7 mm) machine guns each side in the trailing edge of the wing, which retracted into the wing when not in use. These guns were aimed by the copilot through a sighting station at the rear of his cockpit. The guns had a limited field of fire (25 degrees left right and +20 -15 in elevation) to the rear, but with the aircraft's high speed it was thought unlikely that intercepting fighters would attack from any other angle.

Two guns were fitted 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.

Considering the danger of bailing out and being pushed into the rear propellers, designers installed an explosive arrangement to sever the props from the tailcone in event of an emergency.

File:Douglas XB-42 rear.jpg

File:Douglas XB-42A Mixmaster rear view.jpg

File:Douglas XB-42a side view.jpg

File:Douglas XB-42A.jpg

The first XB-42 (43-50224) was delivered to the USAAF and flew at Palm Springs, California on 6 May 1944. Performance was excellent, being basically as described in the original proposal: as fast as the de Havilland Mosquito B.XVI but with defensive armament and twice the bombload over short distances.Francillon 1979, p. 372. The twin bubble canopies proved a bad idea as communications were adversely affected and a single bubble canopy was substituted after the first flight of the second prototype.Winchester 2005, p. 26.

Testing revealed that the XB-42 suffered from some instability as excessive yaw was encountered, as well as propeller vibration and poor engine cooling - all problems that could probably have been dealt with. Due to the ventral vertical stabilizer and rudder surface set's tip being located underneath the fuselage, careful handling during taxiing, takeoff, and landing was required because of limited ground clearance. An integral shock absorber was added to the ventral fin to reduce excessive bending force in the tailcone from a ground strike.{{cite web|url=https://www.flyingmag.com/the-douglas-xb-42-mixmaster-flew-almost-as-fast-as-it-looked/?MailingID=%CAMPAIGNID%&oly_enc_id=4680E9222356C5X|title=History's Unique Aircraft|author=Jason McDowell|date=31 October 2023|website=Flying|publisher=Flying Media Group|access-date=1 November 2023|quote=The Douglas XB-42 'Mixmaster' Flew Almost as Fast as It Looked}}

The end of World War II allowed the USAAF more time to develop new aircraft, and leaders decided to wait for the development of better jet bombers rather than continue with the B-42 program.

In December 1945, Captain Glen Edwards and Lt. Col. Henry E. Warden set a transcontinental speed record by flying the second prototype XB-42 (43-50225) from Long Beach, California to Bolling Air Force Base in Washington, D.C. (c. 2,300 miles). In 5:17 hrs, the XB-42 set a speed record of 433.6 mph (697.8 km/h).O'Leary 1994, p. 10.

The record-breaking XB-42 prototype was destroyed in a crash on 16 December. On a routine flight out of Bolling Field, Washington, D.C., suffered in short order, a landing gear extension problem, failure of the left engine, and as coolant temperatures rose, failure of the right engine. Major Hayduck bailed out at 1,200 feet, Lt. Col. Haney at 800 feet, and the pilot Lt. Col. Fred J. Ascani, after crawling aft to jettison the pusher propellers, at 400 feet – all three survived. The aircraft crashed at Oxon Hill, Maryland. The classified jettisonable propeller technology caused a problem for authorities in explaining what witnesses on the ground thought was the aircraft exploding. Possible fuel management problems were speculated, but this hypothesis was never proven by subsequent investigation.{{Citation needed|date=October 2021}}

The remaining prototype was used in flight test programs, including fulfilling a December 1943 proposal by Douglas to fit uprated engines and underwing Westinghouse 19XB-2A axial-flow turbojets of 1,600 lbf (7.1 kN) thrust each, making it the XB-42A.Francillon 1979, pp. 376–377.

In this configuration, it first flew at Muroc (now Edwards Air Force Base) on 27 May 1947. In testing, it reached 488 mph (785 km/h). After 22 flights, the ventral fin and rudder were damaged in a hard landing in 1947. The XB-42A was repaired but never flew again, and was taken off the USAF inventory on 30 June 1949.

Unit cost was $13.7 million for the program, including the B-43 project.Knaack, Marcelle Size. Post-World War II bombers, 1945-1973. Washington, D.C.: Office of Air Force History, 1988. {{ISBN|0-16-002260-6}}.

The first prototype 43-50224 is in storage awaiting restoration in the Restoration Hangar at the National Museum of the United States Air Force in Dayton, Ohio. The prototype was removed from the USAF inventory in 1949 and given to the National Air and Space Museum in Washington, D.C. The wings were removed for transport but have since been lost. In 2010 the fuselage was transferred, along with the Douglas XB-43 Jetmaster, to the National Museum of the United States Air Force. Once completed, they will be displayed in the museum's Experimental Aircraft Hangar.

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|guns=6 × .50 in (12.7 mm) machine guns, two in twin rear-firing turrets and two fixed forward-firing{{citation|url=http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2653|title=Factsheet: Douglas XB-42|archive-url=https://web.archive.org/web/20080208235949/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2653|archive-date=8 February 2008|publisher=National Museum of the United States Air Force|accessdate=9 June 2010}}

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{{Portal|Aviation}}

{{aircontent

|see also=

• Douglas Cloudster II

|related=

• Douglas XB-43 Jetmaster

|similar aircraft=

|lists=

• List of aircraft of World War II
• List of attack aircraft
• List of bomber aircraft
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}}

{{Reflist}}

{{refbegin}}

• {{cite magazine|last=Boyne|first=Walt|title=The First, The Last, And The Only: The Douglas XB-42/42A/43|magazine=Airpower|date=September 1973|volume=3|number=5|pages=13–14}}
• {{cite book|last=Francillon|first=René J.|title=McDonnell Douglas Aircraft since 1920|url=https://archive.org/details/mcdonnelldouglas00fran_0|url-access=registration|location=London|publisher=Putnam|year=1979|isbn=0-370-00050-1}}
• O'Leary, Michael, ed. "Elegant Failure." America's Forgotten Wings, Volume 1, 1994, pp. 4–11.
• {{cite book|last=Winchester|first=Jim|title=The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters|location=London|publisher=Amber Books|year=2005|isbn=1-904687-34-2}}

{{refend}}

{{commonscat|Douglas XB-42}}

• [https://web.archive.org/web/20110716074057/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2654 XB-42A]
• "Christmas Brings Joy To Everyone, 1945/12/10," Universal Newsreel,1945 - XB-42 news begins at 0:04:36

{{Douglas aircraft}}

{{USAF attack aircraft}}

{{USAF bomber aircraft}}

B-42 Mixmaster

Douglas B-42 Mixmaster

Category:Cancelled military aircraft projects of the United States

Category:Twin-engined single-prop pusher aircraft

Category:Mid-engined aircraft

Category:Aircraft with contra-rotating propellers

Category:Mid-wing aircraft

Category:Aircraft first flown in 1944

Category:Aircraft with auxiliary jet engines