The
Boeing B-50 Superfortress
was a post-World War II revision of the
wartime United
States
B-29
Superfortress with larger Pratt & Whitney R-4360
radial engines, a taller vertical
stabilizer, and other improvements.
Design and development

Boeing B-50D
The B-50 program began life as the
XB-44 Superfortress. One B-29A-5-BN (s/n
42-93845) was modified by
Pratt
& Whitney in 1944 to accept the larger engines; the
resulting
engine testbed first flew in May 1945. If the
engine modification had been included in the B-29 program, the
resulting model was to have been known as the B-29D. However, due
to other structural changes that would also be necessary to address
the increased power, weight and fuel consumption, it was decided to
change its military designation to a new model. Since the B-44
program was only for the engine modification, that designation was
not considered, and in December 1945 the program was named
B-50
Superfortress.
Officially, the aircraft's new designation was justified by the
changes incorporated into the revised aircraft, but according to
Peter M. Bowers, a long-time
Boeing employee and aircraft designer, and a
well-known authority on Boeing aircraft, "the redesignation was an
outright military ruse to win appropriations for the procurement of
an airplane that by its designation appeared to be merely a later
version of an existing model that was being canceled wholesale,
with many existing examples being put into dead storage."
Revisions to the B-50 (from its predecessor B-29) would result in a
top speed just short of 400 mph (644 km/h), faster than
many World War II propeller-powered fighters. Changes included:
- Larger engines
- Redesigned engine nacelles and engine mounts
- Enlarged vertical tail and rudder (to maintain adequate yaw
control during engine-out conditions)
- Reinforced wing structure (required due to increased engine
mass, larger gyroscopic forces from larger propeller, greater fuel
load, and revised landing gear loading)
- Revised routing for engine gases (cooling, intake, exhaust and
intercooler ducts; also oil lines)
- Upgraded fire-control equipment (to control remote
turrets)
- Landing gear strengthening (takeoff weight increased from
133,500 lb/60,555 kg to
173,000 lb/78,471 kg)
- Increased fuel capacity (this was largely addressed by adding
underwing fuel tanks).
- Revisions to flight control systems (the B-29 was already
difficult to fly; with its increased weight the B-50 would have
been much harder to hand-fly).
Redesigned with a larger upper fuselage, the B-50 design would form
the basis for the
Boeing 377 series of
airliners and
C-97/
KC-97 military transports, with 816 of the KC-97
built. The B-29 and B-50s would be phased out with introduction of
the jet powered
B-47 Stratojet.
The B-50 was nicknamed "
Andy Gump" because
the redesigned engine nacelles reminded aircrew of the chinless
newspaper comic character popular at the time.
Operational history

B-50D-90-BO
48-086 with
R-4360 engine differences visible

Boeing B-50D of 15th Air Force while
on detachment to England in May 1953
Boeing built 371 of the various B-50 models and variants between
1947 and 1953, the tanker versions serving until 1965.
A
reconnaissance variant, the
RB-50B (a B-50B conversion) played an important
role in
Cold War espionage.
An
aerial refueling tanker
conversion designated
KB-50 was used in the
Vietnam War.
In 1949, The
Lucky Lady II,
commanded by Captain James Gallagher, became the first airplane to
circle the world nonstop. This was
achieved by refueling the plane in flight.
Although constructed in relatively small numbers, the B-50 was the
last member of the B-29 family and was one of the last
piston-engined bombers built. The B-50 was
retired from its main role as atomic bomber in 1955. A number were
converted into KB-50 tankers and lasted long enough to be deployed
to Southeast Asia in support of tactical operations.
B-50s were grounded and removed completely from inventory when
wreckage of a KB-50 that broke up in flight in 1965 revealed
corrosion problems in the fleet.
No flying examples exist today, although several can be found in
various air museums.
The
USAF Strategic Air Command had B-50
Superfortresses (B-50s and RB-50s) in service from 1948 through
1954.
Variants
- XB-44: One B-29A was handed over to Pratt & Whitney to be fitted with
the new Wasp Major 28-cylinder engines.
Initially designated B-29D, this was eventually changed to B-50A in
December 1945. (x1, converted)
- B-50A--First production version of the B-50.
It had new wings that were stronger and lighter than the units on
the B-29. It also had taller vertical tail than the B-29.
(x60)
- B-50B--Increase in gross weight over the A
model, from 168,480 lb (76,420 kg) to 170,400 lb
(77,290 kg). Also included a new type of lightweight fuel
cell. (x45)
- B-50D--Definitive production version of the
B-50. The 7-piece nose cone window was replaced by a single plastic
cone and a flat bomb-aimer's window. Many included the new
boom-type refueling system. (x222)
- DB-50D--Drone director conversion of a B-50D,
to be used with the GAM-63 RASCAL
missile. (x1, converted)

EB-50B with track-tread
undercarriage
- EB-50B--Single conversion of a B-50B to be
fitted with a track-tread undercarriage. (x1, converted)
- KB-50--Air to air
refueling tanker conversions of the bomber. (x134, converted)
- KB-50J--Tanker B-50s with improved
performance, via two extra General
Electric J47 turbojets under the outer wings. (x112,
converted)
- KB-50K--Tanker conversions of the TB-50H
trainer aircraft. (x24, converted)
- RB-50B--All but one of the B-50Bs were
converted into the recon role. These were fitted with nine cameras
in four stations, weather instruments, and a bomb bay capsule
holding the extra crew members. (x44, converted)
- RB-50E--Special photographic conversions of
the RB-50B, modified at Wichita. (x14, converted)
- RB-50F--Conversions of the RB-50B, fitted with
SHORAN navigation radar for special missions.
(x14, converted)
- RB-50G--Conversions of the RB-50B, fitted with
electronics countermeasures stations along with the SHORAN radar.
(x15, converted)
- TB-50A--Trainer conversion of the B-50A. (x11,
converted)
- TB-50D--Trainer conversion of the B-50D. (x11,
converted)
- TB-50H--Newly built trainer planes. (x24)
- WB-50 --Weather reconnaissance conversion of
the B-50.
- WB-50D--Weather reconnaissance conversions of
outdated B-50Ds, fitted with meteorological equipment. (x36,
converted). Some of these flew highly classified missions for
atmospheric sampling between 1953 and 1955 to detect Soviet
detonation of atomic weapons.
- YB-50C--Version to be fitted with the Variable
Discharge Turbine version of the R-4360 engine. None were
built.
- B-54A--Proposed version of the YB-50C.
- RB-54A--Proposed reconnaissance version of the
YB-50C.
Survivors
- B-50A-5BO 46-0010, "Lucky Lady II", Planes Of Fame,
Chino, California (D)
- B-50D-115BO 49-310, ex-WB-50D,
" 48-0114 ", National Museum of the United States Air
Force
, Wright-Patterson AFB
, Dayton,
Ohio
(D)
- B-50D-120BO 49-0351, ex-WB-50D,
"Flight of the Phoenix ", Castle Air
Museum
, Castle
Airport
(ex-Castle
AFB
), Atwater, California
(D)
- B-50D-125BO 49-0372, ex-KB-50J,
" 372 ", Pima Air and Space Museum
(adjacent to Davis-Monthan AFB
), Tucson,
Arizona
(D)
- B-50D-125BO 49-0389,
ex-KB-50J," 48-014 ", MacDill AFB
, Tampa,
Florida
(D)
Note: On
46-0010 " Lucky Lady II " it has
been reported that nose section is not original to this
airframe.
Operators
Specifications (B-50D)
See also
References
- Notes
- B-50 phase out for B-47
-
http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=369
- Lucky Lady II
- USAFM, Wright-Patterson AFB
- Castle Air Museum
- Pima Air Museum
- Bibliography
- Jones, Lloyd S. U.S. Bombers, B-1 1928 to B-1
1980s. Fallbrook, CA: Aero Publishers, 1962, second edition
1974. ISBN 0-8168-9126-5.
External links