Boeing B 29 Superfortress
That there were senior officers of the US Army Air Corps who were well
aware of the need to procure long-range strategic bombers had been made
clear in the entry dealing with the Boeing B-17. In addition to the
long and drawn out process of getting B-17s into squadron service, the
USAAC had also initiated procurement of more potent aircraft, ordering
a prototype XBLR-1 (Experimental Bomber Long Range-1) from Boeing,
which was built and flown as the XB-15. A competitive XBLR-2 (later
XB-19) was ordered from Douglas Aircraft Company, and after it and the
XB-15 had been evaluated, both were put into 'cold storage' until more
powerful engines became available.
outbreak of war in Europe in 1939 made it essential that USAAC planners
should at least talk about long-range bomber projects, and the initial
identification of such was VHB (very heavy bomber). When it seemed
likely that such an aircraft might have to be deployed over the vast
reaches of the Pacific Ocean the identification VLR (very long-range)
seemed more apt, and it was the VLR project which General Henry H.
('Hap') Arnold, head of the USAAC, got under way at the beginning of
Requests for Proposals were sent to five US aircraft manufacturers on
29 January 1940: in due course design studies were submitted by Boeing,
Consolidated, Douglas and Lockheed, these being allocated the
respective designations XB-29, XB-32, XB-31 and XB- 30. Douglas and
Lockheed subsequently withdrew from the competition, and on 6 September
1940 contracts were awarded to Boeing and Consolidated (Convair) for
the construction and development of two (later three) prototypes of
their respective designs. Convair's XB-32 Dominator was the first to
fly, on 7 September 1942, but extensive development delayed its entry
Boeing, because of the company's foresight, was much further along the
design road in 1940, and being able to convince the USAAC that they
would have production aircraft available within two or three years, had
received orders for more than 1,500 before a prototype was flown. The
reason for the advanced design state of Boeing's proposal was due to
the fact that as early as 1938 the company had offered to the USAAC its
ideas for an improved B-17, with a pressurised cabin to make
high-altitude operations less demanding on the crew. While there was
then no requirement for such an aircraft, the US Army encouraged Boeing
to keep the design updated to meet the changing conditions of war. This
was reflected by the designs identified as Models 316, 322, 333, 334
and 341. The design for the XB-29 was a development of the Model 341,
designated Model 345, and the first of the prototypes made its maiden
flight on 21 September 1942.
USAAC's specification had called for a speed of 400 mph (644 km/h), so
the XB-29 had a high aspect ratio cantilever monoplane wing rnid-set on
the circular- section fuselage. Because such a wing would entail a high
landing speed, the wide-span trailing-edge flaps were of the Fowler
type which effectively increased wing area by almost 20 per cent, thus
allowing a landing to be made at lower speed. Electrically- retractable
tricycle landing gear was provided and, as originally proposed by
Boeing, pressurised accommodation was included for the flight crew. In
addition, a second pressurised compartment just aft of the wing gave
accommodation to crew members who, in the third XB-29 and production
aircraft, sighted defensive gun turrets from adjacent blister windows.
The crew and aft compartments were connected by a crawl- tunnel which
passed over the fore and aft bomb bays. The tail gunner was
accommodated in a pressurised compartment, but this was isolated from
the other crew positions. The powerplant consisted of four Wright
R-3350 Cyclone twin-row radial engines, each with two General Electric
turbochargers mounted one in each side of the engine nacelle. The 16 ft
7 in (5.05 m) diameter four-blade metal propellers were of the
constant-speed and fully-feathering type.
Prototype production was followed by 14 YB-29 service test aircraft,
the first of these flying on 26 June 1943. Deliveries of YB-29s began
almost immediately to the 58th Very Heavy Bombardment Wing (VHBW), a
unit which had been established on 1 June in advance of the first
flight. B-29 production was the largest aircraft manufacturing project
undertaken in the USA during World War 11, with literally thousands of
sub- contractors supplying components or assemblies to the four main
production plants: Boeing at Renton and Wichita; Bell at Mariettal
Georgia; and Martin at Omaha, Nebraska.
Deliveries of production B-29s started in the autumn of 1943, and these
began to equip the 58th VHBW so that it could proceed with training and
get groups ready for operational service. One of the tricky questions
was where to send the units initially, for the Allied/US agreement to
end the war in Europe first would suggest their deployment against
Germany and German- occupied territories. However, as 1943 was nearing
its end, the situation in the Far East suggested that they could be
used more effectively in that area, and the decision was made to send
them to operate in the theatre for which they had been designed.
4 April 1944, the 20th Air Force was established to operate the B-29s,
but as at that time no island bases were available from which the B-29s
could strike at the Japanese home islands, preparations had already
been made for them to operate initially from bases in China. Something
like half a million Chinese farmers and peasants laboured with simple
hand tools to create four airfields for the B-29s in the Chengtu area
of Szechwan province, and the first aircraft landed at Kwanghan air
base on 24 April 1944. By 10 May all four bases were operational and
the first attack against a Japanese home island target, the Imperial
Iron and Steel Works at Yawata, Kyushu, was made by 77 aircraft of XX
Bomber Command on 15 June 1944. There were many problems to these
operations from the Chinese bases, not least of which was logistics.
about 150 B-29s were used continually to haul essential fuel and
supplies to Kunming, over the Himalayan 'hump' from India, thus making
it possible for 100 B-29s to remain operational. But it was not until
the establishment of bases on Saipan, Guam and Tinian in the Marianas
that the major B-29 offensive could be launched against Japan.
first of XXI Bomber Command's Superfortresses landed on Saipan's Isley
Field on 12 October 1944; Tinian's first airstrip was operational in
late December; and that on Guwn on 2 February 1945. But the answer to
the question of how to employ the B-29s most effectively was not
resolved until the night of 9/10 March 1945, when 334 aircraft flying
from Guam, Saipan and Tinian set out to attack Tokyo, some 1,600 miles
(2 575 km) distant. When they returned they had recorded the most
devastating air attack ever made, with 83,793 people dead, 40,918
injured and 1,008,005 rendered homeless.
This was to be the continuing pattern for XXI Bomber Command, while XX
Bomber Command reduced Formosa's towns and docks to little more than
rubble. It remained only for the B-29s Enola Gay and Bock's Car, of the
393rd Bombardment Squadron, to drop the world's only operational atomic
bombs over Hiroshima and Nagasaki on 6 and 9 August 1945 respectively
to bring World War 11 to a close. In these closing stages XXI Bomber
Command B-29s had dropped some 160,000 tons (162 560 tonnes) of bombs
on Japanese targets, averaging 1,193 tons (1 212 tonnes) per day during
the last three months: the USAAC's VLR project was justified.
B-29 production totalled 1,644 from Boeing's Wichita plant, with 668
built by Bell and 536 by Martin. The Renton plant produced only B-29As,
with slightly increased span and changes in fuel capacity and armament:
production continued until May 1946 and totalled 1,122 aircraft.
Washington (RAF name for B-29s loaned to the UK between
1950-1958); Bull (NATO code name for Russian TU-4, a
near-exact copy of the B-29).
Engines: Four 2,200-hp Wright
R-3350-23-23A/-41 Cyclone 18 turbocharged radial piston engines.
Weight: Empty 70,140 lbs.,
Max Takeoff 124,000 lbs.
Wing Span: 141ft. 3in.
Length: 99ft. 0in.
Height: 29ft. 7in.
Maximum Speed: 358 mph
Cruising Speed: 230 mph
Ceiling: 31,850 ft.
Range: 3,250 miles
wo 12.7-mm (0.5-inch) machine guns
in each of remote-controlled turrets, plus three 12.7-mm (0.5-inch)
machine guns, or two 12.7-mm guns and one 20-mm cannon in the tail
Number Built: 3,970
Number Still Airworthy: