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 |
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.
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.
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]
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]
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.
Data from Francillon 1979 p. 377
General characteristics
Performance
Armament
Related development
Related lists
The Consolidated B-24 Liberator is an American heavy bomber, designed by Consolidated Aircraft of San Diego, California. It was known within the company as the Model 32, and some initial production aircraft were laid down as export models designated as various LB-30s, in the Land Bomber design category.
The McDonnell XF-88 Voodoo was a long-range, twinjet fighter aircraft with swept wings designed for the United States Air Force. Although it never entered production, its design was adapted for the subsequent supersonic F-101 Voodoo.
The Douglas B-18 Bolo is an American heavy bomber which served with the United States Army Air Corps and the Royal Canadian Air Force during the late 1930s and early 1940s. The Bolo was developed by the Douglas Aircraft Company from their DC-2 as a replacement for the Martin B-10.
The Martin B-26 Marauder is an American twin-engined medium bomber that saw extensive service during World War II. The B-26 was built at two locations: Baltimore, Maryland, and Omaha, Nebraska, by the Glenn L. Martin Company.
The Consolidated B-32 Dominator was an American heavy strategic bomber built for United States Army Air Forces during World War II, which had the distinction of being the last Allied aircraft to be engaged in combat during World War II; that engagement also resulted in the last American to die in air combat in World War II. It was developed by Consolidated Aircraft in parallel with the Boeing B-29 Superfortress as a fallback design should the B-29 prove unsuccessful. The B-32 reached units in the Pacific only in mid-May 1945, and subsequently saw only limited combat operations against Japanese targets before the formal end of the war on 2 September 1945. Most of the extant orders of the B-32 were canceled shortly thereafter and only 118 B-32 airframes of all types were built.
The Douglas XTB2D Skypirate was a torpedo bomber intended for service with the United States Navy's Midway- and Essex-class aircraft carriers; it was too large for earlier decks. Two prototypes were completed, but the dedicated torpedo bomber was becoming an outdated concept, and with the end of World War II, the type was deemed unnecessary and cancelled.
The Northrop YB-35/XB-35, Northrop designation N-9 or NS-9, were experimental heavy bomber aircraft developed by the Northrop Corporation for the United States Army Air Forces during and shortly after World War II. The airplane used the radical and potentially very efficient flying wing design, in which the tail section and fuselage are eliminated and all payload is carried in a thick wing. Only prototypes and pre-production aircraft were built, although interest remained strong enough to warrant further development of the design as a jet bomber, under the designation YB-49.
The Douglas A-26 Invader is an American twin-engined light bomber and ground attack aircraft. Built by Douglas Aircraft Company during World War II, the Invader also saw service during several major Cold War conflicts. A limited number of highly modified United States Air Force aircraft served in Southeast Asia until 1969. It was a fast aircraft capable of carrying a large bomb load. A range of guns could be fitted to produce a formidable ground-attack aircraft.
The Douglas Y1B-7 was a 1930s American bomber aircraft. It was the first US monoplane given the B- 'bomber' designation. The monoplane was more practical and less expensive than the biplane, and the United States Army Air Corps chose to experiment with monoplanes for this reason. At the time the XB-7 was ordered, it was being tested by Douglas Aircraft as an observational plane.
The Douglas XB-19 was a four-engined, piston-driven heavy bomber produced by the Douglas Aircraft Company for the United States Army Air Forces (USAAF) during the early 1940s. The design was originally given the designation XBLR-2. It was the largest bomber built for the USAAF until 1946, with the Convair B-36 surpassing it in size.
The Nakajima G8N Renzan was a four-engined long-range bomber designed for use by the Imperial Japanese Navy. The Navy designation was "Type 18 land-based attack aircraft" (十八試陸上攻撃機); the Allied code name was "Rita".
The Boeing YB-9 was the first all-metal monoplane bomber aircraft designed for the United States Army Air Corps. The YB-9 was a much enlarged twin-engine development of Boeing's single-engine Model 200 Monomail commercial transport.
The Douglas XB-43 Jetmaster is an American 1940s jet-powered prototype bomber. The XB-43 was a development of the XB-42, replacing the piston engines of the XB-42 with two General Electric J35 engines of 4,000 lbf (17.8 kN) thrust each. Despite being the first American jet bomber to fly, it suffered stability issues and the design did not enter production.
The Nakajima G5N Shinzan was a four-engined long-range heavy bomber designed and built for the Imperial Japanese Navy prior to World War II. The Navy designation was "Experimental 13-Shi Attack Bomber"; the Allied code name was "Liz".
The Douglas O-31 was the Douglas Aircraft Company's first monoplane observation straight-wing aircraft used by the United States Army Air Corps.
The Avro Type 557 Ava was a British twin-engined biplane torpedo bomber of the 1920s. It was developed by Avro to meet a requirement for a heavy torpedo bomber for the Royal Air Force but was unsuccessful, only two prototypes being built.
The Rikugun Ki-93 was a prototype Japanese twin-engined fighter aircraft of the Second World War. Designed by the Army Aerotechnical Research Institute, to be a heavy fighter armed with large calibre cannon to serve in the anti-shipping or bomber destroyer roles, only one example of the Ki-93 was completed; this was damaged on its maiden flight, and destroyed by American bombing before it could be flown again.
The Douglas DC-8 was an American piston-engined airliner project by Douglas Aircraft. A concept developed more than a decade before the DC-8 jetliner, the piston-engined DC-8 was to have propellers in the tail, an idea first used at Douglas by Edward F. Burton on a fighter project. The airliner project was canceled after development costs made it commercially unviable.
The Douglas Cloudster II was an American prototype five-seat light aircraft of the late 1940s. It was of unusual layout, with two buried piston engines driving a single pusher propeller. Only a single example was built, which flew only twice, as it proved too expensive to be commercially viable.
The Douglas Model 423 was a bomber aircraft design developed by American aircraft manufacturer Douglas to compete with the Convair B-36 design for a major U.S. Army Air Force contract for an intercontinental bomber in 1941. Although identified as the Douglas XB-31 in some publications, the project documents indicate that it was designed much later than the R40-B competition.
The Douglas XB-42 'Mixmaster' Flew Almost as Fast as It Looked