The Douglas XB-42 Mixmaster was an experimental
bomber aircraft
A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped from an aircraf ...
, designed for a high top speed. The unconventional approach was to mount the two engines within the
fuselage
The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...
driving a pair of
contra-rotating propellers
Aircraft equipped with contra-rotating propellers, also referred to as CRP, coaxial contra-rotating propellers, or high-speed propellers, apply the maximum power of usually a single piston or turboprop engine to drive a pair of coaxial propell ...
mounted at the tail in a
pusher configuration
In an aircraft with a pusher configuration (as opposed to a tractor configuration), the propeller(s) are mounted behind their respective engine(s). Since a pusher propeller is mounted behind the engine, the drive shaft is in compression in nor ...
, leaving the wing and fuselage clean and free of drag-inducing protrusions.
Two prototype aircraft were built, but the end of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
changed priorities and the advent of the jet engine gave an alternative way toward achieving high speed.
Design and development
The XB-42 was developed initially as a private venture; an unsolicited proposal was presented to the
United States Army Air Forces
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
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
The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 Fl ...
'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
A tricycle, sometimes abbreviated to trike, is a human-powered (or gasoline or electric motor powered or assisted, or gravity powered) three-wheeled vehicle.
Some tricycles, such as cycle rickshaws (for passenger transport) and freight trikes, ...
and a full, four surface
cruciform tail __NOTOC__
The cruciform tail is an aircraft empennage configuration which, when viewed from the aircraft's front or rear, looks much like a cross. The usual arrangement is to have the horizontal stabilizer intersect the vertical tail somewhere ...
was fitted, whose ventral fin/rudder unit prevented 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 more 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.
Operational history
![Douglas XB-42A](https://upload.wikimedia.org/wikipedia/commons/9/9e/Douglas_XB-42A.jpg)
The first XB-42 (43-50224) was delivered to the USAAF and flew at
Palm Springs, California
Palm Springs (Cahuilla: ''Séc-he'') is a desert resort city in Riverside County, California, United States, within the Colorado Desert's Coachella Valley. The city covers approximately , making it the largest city in Riverside County by land a ...
on 6 May 1944. Performance was excellent, being basically as described in the original proposal: as fast as the
de Havilland Mosquito
The de Havilland DH.98 Mosquito is a British twin-engined, shoulder-winged, multirole combat aircraft, introduced during the Second World War. Unusual in that its frame was constructed mostly of wood, it was nicknamed the "Wooden Wonder", or ...
B.XVI but with defensive armament and twice the bombload over short distances. 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
A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, sta ...
and
rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...
surface set's tip being located underneath the fuselage, careful handling during taxiing, takeoff, and landing was required because of limited ground clearance.
The end of World War II allowed the Air Force to consider possibilities with 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.
In December 1945, Captain
Glen Edwards and Lt. Col. Henry E. Warden set a new transcontinental speed record when they flew the second prototype XB-42 (43-50225) from
Long Beach, California
Long Beach is a city in Los Angeles County, California. It is the 42nd-most populous city in the United States, with a population of 466,742 as of 2020. A charter city, Long Beach is the seventh-most populous city in California.
Incorporate ...
to
Bolling Air Force Base
Bolling Air Force Base or Bolling AFB was a United States Air Force base in Washington, D.C. In 2010, it was merged with Naval Support Facility Anacostia to form Joint Base Anacostia–Bolling. From its beginning, the installation has hosted elem ...
in
Washington, D.C.
)
, image_skyline =
, image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...
(c. 2,300 miles). In just 5 hours, 17 minutes, 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.
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
The Westinghouse J30, initially known as the Westinghouse 19XB, was a turbojet engine developed by Westinghouse Electric Corporation. It was the first American-designed turbojet to run, and only the second axial-flow turbojet to run outside German ...
axial-flow
turbojet
The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and ...
s 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
Edwards Air Force Base (AFB) is a United States Air Force installation in California. Most of the base sits in Kern County, but its eastern end is in San Bernardino County and a southern arm is in Los Angeles County. The hub of the base is E ...
) on 27 May 1947. In testing, it reached 488 mph (785 km/h). After 22 flights, the lower vertical stabilizer 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.
Surviving aircraft
The first prototype 43-50224 - in storage awaiting restoration in the Restoration Hangar at the
National Museum of the United States Air Force
The National Museum of the United States Air Force (formerly the United States Air Force Museum) is the official museum of the United States Air Force located at Wright-Patterson Air Force Base, northeast of Dayton, Ohio. The NMUSAF is the ...
in
Dayton, Ohio
Dayton () is the sixth-largest city in the U.S. state of Ohio and the county seat of Montgomery County. A small part of the city extends into Greene County. The 2020 U.S. census estimate put the city population at 137,644, while Greater Day ...
. The prototype was removed from the USAF inventory in 1949 and given to the
National Air and Space Museum
The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States.
Established in 1946 as the National Air Museum, it opened its main building on the Nat ...
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 late 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)
See also
References
Citation
Bibliography
*
*
* O'Leary, Michael, ed. "Elegant Failure." ''America's Forgotten Wings'', Volume 1, 1994, pp. 4–11.
*
External links
XB-42A*
"Christmas Brings Joy To Everyone, 1945/12/10," ''Universal Newsreel,''1945
{{USAF bomber aircraft
B-42 Mixmaster
Douglas B-42 Mixmaster
Cancelled military aircraft projects of the United States
Twin-engined single-prop pusher aircraft
Mid-engined aircraft
Aircraft with contra-rotating propellers
Mid-wing aircraft
Aircraft first flown in 1944
Aircraft with auxiliary jet engines