XB-43 Jetmaster

infobox Aircraft
name=XB-43 Jetmaster
type=Prototype bomber aircraft
manufacturer=Douglas Aircraft Company


caption=
designer=
first flight=17 May 1946
introduced=n/a
retired=
status=
primary user=
more users=
produced=
number built=2
unit cost=
developed from=XB-42 Mixmaster
variants with their own articles=The Douglas XB-43 Jetmaster was an American 1940s jet-powered prototype bomber aircraft. 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 pounds-force (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.

Design and development

United States Army Air Forces (USAAF) leaders in the Air Materiel Command began to consider the possibilities of jet-propelled bombers as far back as October 1943. At that time, Douglas Aircraft was just beginning to design a promising twin-engine bomber designated the XB-42. Reciprocating engines powered this airplane but they were buried in the fuselage, leaving the laminar-airfoil wing clean of any drag-inducing pylon mounts or engine cowlings. The airframe appeared ideally suited to test turbojet propulsion. Douglas confirmed the feasibility of the concept and the USAAF amended the XB-42 contract in March 1944 to include the development of two turbojet-powered XB-43s.

The Douglas design team convinced the Army that modifying the XB-42 static test airframe into the first XB-43 was a relatively straightforward process that would save time and money compared to developing a brand new design. Douglas replaced the two Allison V-1710 engines with a pair of General Electric (GE) J35 turbojets, then cut two air intakes into each side of the fuselage, aft of the pressurized cockpit. Removing the propellers and drive shafts freed enough space for two long jet exhaust ducts. Without the propellers, there was no chance of striking the blade tips on the runway, so the bottom section of the vertical fin was also removed. Douglas compensated for the loss of yaw stability by enlarging the upper vertical fin.

Douglas Aircraft was keen to mass-produce the new bomber and the USAAF considered ordering 50. The company was poised to roll out as many as 200 B-43s per month in two versions: a bomber equipped with a clear plastic nose for the bombardier, and an attack aircraft without the clear nose and bombing station but carrying 16 forward-firing .50 caliber machine guns and 36 five-inch rockets. Nothing came of these plans. The USAAF was already moving ahead with a new bomber, the North American XB-45 Tornado, designed from the outset for turbojet power and promising a quantum leap in every category of performance. There was too much of the propeller and not enough of the turbojet embodied in the basic design of the Douglas bomber.

Testing

As Douglas predicted, the work itself was not overly complex but almost two years were required to ready the airplane for flight. The end of World War II caused a general slowdown within the aircraft industry and GE was late delivering the engines. When they were at last installed and tested on the ground, one of the units failed catastrophically. Compressor blades exploded through the engine casing, damaging the surrounding airframe and injuring a ground technician. Another seven-month delay ensued for repairs. America's first turbojet bomber finally flew from Muroc Army Air Base on 17 May 1946, piloted by Douglas test pilot, Bob Brush, accompanied by engineer Russell Thaw.

Caught in a momentous technological shift, the XB-43 contributed to developing procedures for flying the new jet bombers, and it gave yeoman service testing new turbojet engines. Douglas completed the second airplane, AAF serial number "44-61509", in May 1947 and delivered it to Muroc Air Force Base, California, in April 1948. The USAAF soon replaced one J35 turbojet engine with a General Electric J47. Douglas delivered the second prototype, designated YB-43, in April 1948. That aircraft was nicknamed "Versatile II" by USAAF personnel. When the clear plastic nose began to crack from variations in temperature at high and low altitudes, mechanics fashioned a more durable replacement made from plywood. To keep it flying, the US Air Force cannibalized parts from the first XB-43 after it was damaged in February 1951. "Versatile II" flew more than 300 hours until its retirement in late 1953.

XB-43, YB-43 and A-43

The US Air Force only considered the first prototype to fall under the XB-43 designation. The second prototype, though functionally identical to the first, was designated YB-43, consistent with its status as a follow-on prototype under the Army's designation system for aircraft. At one point, the aircraft may have also been designated as "attack" aircraft, A-43, [ [http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2667 Fact Sheets : Douglas YB-43 Jetmaster : Douglas YB-43 Jetmaster ] ] which is not to be confused with the Curtis XP-87, a project which started as an attack aircraft under the same designation. [ [http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=3183 Fact Sheets : Curtiss A-43 : Curtiss A-43 ] ] The A-43 was to have eight machine guns in a solid nose replacing the bombadier's position.

urvivors

The YB-43 flew until it was turned over to the Smithsonian Institution in 1954. It now rests in the Smithsonian's Paul Garber Facility (National Air and Space Museum) in Suitland, Maryland.

pecifications (XB-43)

aircraft specifications

plane or copter?=plane
jet or prop?=jet

crew=3
length main=51 ft 5 in
length alt=15.7 m
span main=71 ft 2 in
span alt=21.7 m
height main=24 ft 3 in
height alt=7.4 m
area main=563 ft²
area alt=52.3 m²
empty weight main=22,890 lb
empty weight alt=10,380 kg
loaded weight main=40,000 lb
loaded weight alt=18,000 kg
max takeoff weight main=
max takeoff weight alt=

engine (jet)=General Electric J35-GE-3
type of jet=turbojets
number of jets=2
thrust main=4,000 lbf
thrust alt=18 kN

max speed main=507 mph
max speed alt=440 knots, 816 km/h
range main=2,500 mi
range alt=2,200 nm, 4,000 km
ceiling main=38,500 ft
ceiling alt=11,700 m
climb rate main=2,470 ft/min
climb rate alt=753 m/min
loading main=71 lb/ft²
loading alt=350 kg/m²
thrust/weight=0.20

guns=
** 2× 0.50 in (12.7 mm) machine guns in a remotely operated tail mount, never intstalled.
** Planned attack variant: 8× 0.50 in (12.7 mm) machine guns in solid nose
bombs=8,000 lb (3,600 kg)

ee also

aircontent

similar aircraft=

related=
* XB-42 Mixmaster

sequence=
* YB-40 - XB-41 - XB-42 - XB-43 - XB-44 - B-45 - XB-46

lists=
* List of bomber aircraft
* List of military aircraft of the United States

see also=

References

Notes

Bibliography

* Jones, Lloyd. "U.S. Bombers". Fallbrook, California: Aero Publishers, 1974. ISBN 0-8168-9126-5.
* Wagner, Ray. "American Combat Planes". New York: Doubleday & Company, Inc., 1968. ISBN 0-385-04134-9.

External links

* [http://www.nasm.si.edu/research/aero/aircraft/douglas_xb43.htm Smithsonian National Air and Space Museum]
* [http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2655 National Museum of the United States Air Force: XB-43 Data Sheet]
* [http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=2667 National Museum of the United States Air Force: YB-43 Data Sheet]