https://en.wikipedia.org/wiki/Boeing_B-29_Superfortress
The Boeing B-29 Superfortress is a four-engine propeller-driven heavy bomber
designed by Boeing which was flown primarily by the United States during World
War II and the Korean War. It was one of the largest aircraft operational during
World War II and featured state of the art technology. It was the single most
expensive weapons project undertaken by the United States in World War II,
exceeding the cost of the Manhattan Project by between 1 and 1.7 billion
dollars.[4] It featured a pressurized cabin, all dual wheeled, tricycle landing
gears, and a remote, computer-controlled fire-control system that directed four
machine gun turrets that could be operated by a single gunner and a fire-control
officer. A manned tail gun installation was semi-remote. The name
"Superfortress" continued the pattern Boeing started with its well-known
predecessor, the B-17 Flying Fortress. Designed for the high-altitude strategic
bomber role, the B-29 also excelled in low-altitude nighttime incendiary bombing
missions. One of the B-29's final roles during World War II was carrying out the
atomic bomb attacks on Hiroshima and Nagasaki.
Because of the B-29's highly advanced design, unlike many other World War II-era
bombers, the Superfortress remained in service long after the war ended, with a
few even being employed as flying television transmitters for the Stratovision
company. The B-29 served in various roles throughout the 1950s. The Royal Air
Force flew the B-29 as the Washington until phasing out the type in 1954. The
Soviet Union produced an unlicensed reverse-engineered copy as the Tupolev Tu-4.
The B-29 was the progenitor of a series of Boeing-built bombers, transports,
tankers, reconnaissance aircraft and trainers including the B-50 Superfortress
(the first aircraft to fly around the world non-stop) which was essentially a
re-engined B-29. The type was finally retired in the early 1960s. The B-29
production total was 3,970 aircraft. Dozens of B-29s remain as static displays
but only two examples, Fifi and Doc, have been restored to flying status; with
Doc flying again for the first time from McConnell AFB on July 17, 2016.[5]
A transport developed from the B-29 was the Boeing C-97 Stratofreighter, first
flown in 1944, followed by its commercial airliner variant, the Boeing Model 377
Stratocruiser in 1947. This bomber-to-airliner derivation was similar to the
B-17/Model 307 evolution. In 1948 Boeing introduced a tanker variant of the B-29
as the KB-29, followed by the Model 377-derivative KC-97 introduced in 1950. A
heavily modified line of outsized-cargo variants of the Stratocruiser is the
Guppy / Mini Guppy / Super Guppy which remain in service today with operators
such as NASA.
Role
Strategic bomber
Manufacturer
Boeing
First flight
21 September 1942
Introduction
8 May 1944
Retired
21 June 1960
Status
retired (see Survivors)
Primary users
United States Army Air Forces
United States Air Force
Royal Air Force
Produced
Number built
3,970
Unit cost
US$639,188
Variants
All models
Boeing KB-29 Superfortress
XB-39 Superfortress
Boeing XB-44 Superfortress
Boeing B-50 Superfortress
Developed into
Boeing 377 Stratocruiser
Tupolev Tu-4
The revolutionary General Electric Central Fire Control system on the B-29
directed four remotely controlled turrets armed with two .50 Browning M2 machine
guns each. Some turrets were made according to patents from the Tucker Gun
Turret. All weapons were aimed optically with targeting computed by analog
electrical instrumentation. There were five interconnected sighting stations
located in the nose and tail positions and three Plexiglas blisters in the
central fuselage. Five General Electric analog computers (one dedicated to each
sight) increased the weapons' accuracy by compensating for factors such as
airspeed, lead, gravity, temperature and humidity. The computers also allowed a
single gunner to operate two or more turrets (including tail guns)
simultaneously. The gunner in the upper position acted as fire control officer,
managing the distribution of turrets among the other gunners during combat. The
tail position initially had two .50 Browning machine guns and a single M2 20 mm
cannon. Later aircraft had the 20 mm cannon removed, and sometimes replaced by a
third machine gun.
A fully pressurized bomber design
The crew enjoyed, for the first time in a bomber, full-pressurization comfort.
This first-ever cabin pressure system for an Allied production bomber was
developed for the B-29 by Garrett AiResearch.[N 4] The nose and the cockpit were
pressurized, but the designers were faced with deciding whether to have bomb
bays that were not pressurized, between fore and aft pressurized sections, or a
fully pressurized fuselage with the need to de-pressurize to drop their loads.
The solution was a long tunnel over the two bomb bays so as not to interrupt
pressurization during bombing. Crews could crawl back and forth between the fore
and aft sections, with both areas and the tunnel pressurized. The bomb bays were
not pressurized.
The Soviet experience in developing a four-engined heavy bomber was limited. The
Petlyakov Pe-8 equipped the VVS starting in 1940 however only some 93 examples
were ever built. During 1944 and 1945 five B-29s made emergency landings in
Soviet territory after bombing raids on Japanese Manchuria and Japan. In
accordance with Soviet neutrality in the Pacific War, the bombers were interned
and kept by the Soviets, despite American requests for their return. Through
reverse engineering the American B-29 were, instead, used by the Soviets as a
pattern for the Tupolev Tu-4.
Specifications (B-29)
General characteristics
Crew: 11 (Pilot, Co-pilot, Bombardier, Flight Engineer, Navigator, Radio
Operator, Radar Observer, Right Gunner, Left Gunner, Central Fire Control, Tail
Gunner)
Length: 99 ft 0 in (30.18 m)
Wingspan: 141 ft 3 in (43.06 m)
Height: 27 ft 9 in (8.45 m)
Aspect ratio: 11.50:1
Empty weight: 74,500 lb (33,800 kg)
Loaded weight: 120,000 lb (54,000 kg)
Max. takeoff weight: 133,500 lb (60,560 kg) ; 135,000 lb plus combat load
radial engines, 2,200 hp (1,640 kW) each
Zero-lift drag coefficient: 0.0241
Performance
Maximum speed: 357 mph (310 knots, 574 km/h)
Cruise speed: 220 mph (190 knots, 350 km/h)
Stall speed: 105 mph (91 knots, 170 km/h)
Range: 3,250 mi (2,820 nmi, 5,230 km)
Ferry range: 5,600 mi (4,900 nmi, 9,000 km,[80])
Service ceiling: 31850 ft [26] (9,710 m)
Rate of climb: 900 ft/min (4.6 m/s)
Power/mass: 0.073 hp/lb (121 W/kg)
Lift-to-drag ratio: 16.8
Armament
turrets.[81] (omitted from Silverplate B-29s)
removed)[N 11]
Bombs: 20,000 lb (9,000 kg) standard loadout.
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