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Douglas XB-42 Mixmaster

January 01, 1970

The Douglas XB-42 Mixmaster was an experimental American 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 in a pusher configuration, leaving the wing and fuselage clean and free of drag-inducing protrusions.

XB-42 Mixmaster
XB-42
Role Medium bomber
Manufacturer Douglas Aircraft Company
First flight 6 May 1944
Status Canceled in 1948
Primary users United States Army Air Forces (intended)
United States Air Force (intended)
Number built 2
Developed into Douglas XB-43 Jetmaster

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.

Design and development edit

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.[1]

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.[1]

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.[1]

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.[2]

Operational history edit

 
View of the contraprop and cruciform tail.
 
Rear view of the XB-42A in May 1947
 
XB-42A with podded 19XB-2 jets.[3]
 
XB-42A

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.[4] 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.[5][3]

Testing revealed that the XB-42 suffered from some instability as excessive yaw was encountered,[5] 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.[2]

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).[6]

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]

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.[7]

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.[7]

Unit cost was $13.7 million for the program, including the B-43 project.[8]

Surviving aircraft edit

The first prototype 43-50224 - 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., in whose care it remains although it has never been placed on display. 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 in Dayton, Ohio where they are awaiting restoration in the Restoration Hangars. Once completed, they will be displayed in the museum's Experimental Aircraft Hangar.

Specifications (XB-42) edit

Data from Francillon 1979 p. 377

General characteristics

  • Crew: three (pilot, co-pilot, bombardier)
  • Length: 53 ft 8 in (16.36 m)
  • Wingspan: 70 ft 6 in (21.49 m)
  • Height: 18 ft 10 in (5.74 m)
  • Wing area: 555 sq ft (51.6 m2)
  • Empty weight: 20,888 lb (9,475 kg)
  • Max takeoff weight: 35,702 lb (16,194 kg)
  • Powerplant: 2 × Allison V-1710-125 liquid-cooled V12 engines, 1,800 hp (1,300 kW) each

Performance

  • Maximum speed: 410 mph (660 km/h, 360 kn) at 23,440 feet (7,140 m)
  • Range: 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)
  • Power/mass: 0.16 hp/lb

Armament

  • Guns: 6 × .50 in (12.7 mm) machine guns, two in twin rear-firing turrets and two fixed forward-firing[9]
  • Bombs: 8,000 pounds (3,600 kg) in internal bay

See also edit

Related development

Related lists

References edit

Citation edit

  1. ^ a b c Winchester 2005, p. 27.
  2. ^ a b Jason McDowell (31 October 2023). "History's Unique Aircraft". Flying. Flying Media Group. Retrieved 1 November 2023. The Douglas XB-42 'Mixmaster' Flew Almost as Fast as It Looked
  3. ^ a b Francillon 1979, p. 376.
  4. ^ Francillon 1979, p. 372.
  5. ^ a b Winchester 2005, p. 26.
  6. ^ O'Leary 1994, p. 10.
  7. ^ a b Francillon 1979, pp. 376–377.
  8. ^ Knaack, Marcelle Size. Post-World War II bombers, 1945-1973. Washington, D.C.: Office of Air Force History, 1988. ISBN 0-16-002260-6.
  9. ^ , National Museum of the United States Air Force, archived from the original on 8 February 2008, retrieved 9 June 2010

Bibliography edit

  • Boyne, Walt (September 1973). "The First, The Last, And The Only: The Douglas XB-42/42A/43". Airpower. Vol. 3, no. 5. pp. 13–14.
  • Francillon, René J. (1979). McDonnell Douglas Aircraft since 1920. London: Putnam. ISBN 0-370-00050-1.
  • O'Leary, Michael, ed. "Elegant Failure." America's Forgotten Wings, Volume 1, 1994, pp. 4–11.
  • Winchester, Jim (2005). The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters. London: Amber Books. ISBN 1-904687-34-2.

External links edit

 
Wikimedia Commons has media related to Douglas XB-42.

January 01, 1970
douglas, mixmaster, experimental, american, bomber, aircraft, designed, high, speed, unconventional, approach, mount, engines, within, fuselage, driving, pair, contra, rotating, propellers, mounted, tail, pusher, configuration, leaving, wing, fuselage, clean, . The Douglas XB 42 Mixmaster was an experimental American 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 in a pusher configuration leaving the wing and fuselage clean and free of drag inducing protrusions XB 42 Mixmaster XB 42 Role Medium bomber Manufacturer Douglas Aircraft Company First flight 6 May 1944 Status Canceled in 1948 Primary users United States Army Air Forces intended United States Air Force intended Number built 2 Developed into Douglas XB 43 Jetmaster 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 Contents 1 Design and development 2 Operational history 3 Surviving aircraft 4 Specifications XB 42 5 See also 6 References 6 1 Citation 6 2 Bibliography 7 External linksDesign and development editThe 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 1 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 1 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 1 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 2 Operational history edit nbsp View of the contraprop and cruciform tail nbsp Rear view of the XB 42A in May 1947 nbsp XB 42A with podded 19XB 2 jets 3 nbsp XB 42A 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 4 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 5 3 Testing revealed that the XB 42 suffered from some instability as excessive yaw was encountered 5 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 2 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 6 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 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 7 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 7 Unit cost was 13 7 million for the program including the B 43 project 8 Surviving aircraft editThe first prototype 43 50224 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 in whose care it remains although it has never been placed on display 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 in Dayton Ohio where they are awaiting restoration in the Restoration Hangars Once completed they will be displayed in the museum s Experimental Aircraft Hangar Specifications XB 42 editData from Francillon 1979 p 377General characteristicsCrew three pilot co pilot bombardier Length 53 ft 8 in 16 36 m Wingspan 70 ft 6 in 21 49 m Height 18 ft 10 in 5 74 m Wing area 555 sq ft 51 6 m2 Empty weight 20 888 lb 9 475 kg Max takeoff weight 35 702 lb 16 194 kg Powerplant 2 Allison V 1710 125 liquid cooled V12 engines 1 800 hp 1 300 kW each Performance Maximum speed 410 mph 660 km h 360 kn at 23 440 feet 7 140 m Range 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 Power mass 0 16 hp lb Armament Guns 6 50 in 12 7 mm machine guns two in twin rear firing turrets and two fixed forward firing 9 Bombs 8 000 pounds 3 600 kg in internal baySee also edit nbsp Aviation portal Douglas Cloudster II Related development Douglas XB 43 Jetmaster Related lists List of aircraft of World War II List of attack aircraft List of bomber aircraft List of military aircraft of the United StatesReferences editCitation edit a b c Winchester 2005 p 27 a b Jason McDowell 31 October 2023 History s Unique Aircraft Flying Flying Media Group Retrieved 1 November 2023 The Douglas XB 42 Mixmaster Flew Almost as Fast as It Looked a b Francillon 1979 p 376 Francillon 1979 p 372 a b Winchester 2005 p 26 O Leary 1994 p 10 a b Francillon 1979 pp 376 377 Knaack Marcelle Size Post World War II bombers 1945 1973 Washington D C Office of Air Force History 1988 ISBN 0 16 002260 6 Factsheet Douglas XB 42 National Museum of the United States Air Force archived from the original on 8 February 2008 retrieved 9 June 2010 Bibliography edit Boyne Walt September 1973 The First The Last And The Only The Douglas XB 42 42A 43 Airpower Vol 3 no 5 pp 13 14 Francillon Rene J 1979 McDonnell Douglas Aircraft since 1920 London Putnam ISBN 0 370 00050 1 O Leary Michael ed Elegant Failure America s Forgotten Wings Volume 1 1994 pp 4 11 Winchester Jim 2005 The World s Worst Aircraft From Pioneering Failures to Multimillion Dollar Disasters London Amber Books ISBN 1 904687 34 2 External links edit nbsp Wikimedia Commons has media related to Douglas XB 42 XB 42A Christmas Brings Joy To Everyone 1945 12 10 Universal Newsreel 1945 XB 42 news begins at 0 04 36 Retrieved from https en wikipedia org w index php title Douglas XB 42 Mixmaster amp oldid 1219382689, wikipedia, wiki, book, books, library,

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