Throughout the 1930s, new bomber aircraft emerged in all countries.
However, these older models were inadequate to carry out the theories of
strategic bombing--they could neither travel far enough nor carry a
heavy enough bomb load. Eventually, two American planes were designed
that embodied the qualities of the perfect bomber--the Boeing B-17 and
B-29. Both planes helped the Allies win the war and define the reality
of air power.
In
April 1934, the U.S. Army Air Corps requested bids for a multiengine
bomber that could carry a bomb load of 2,000 pounds (907 kilograms) for
at least 1,020 miles (1,642 kilometres) at a speed of 200 miles per hour
(322 kilometres per hour). Boeing proposed the four-engine Model 299,
with its all-metal construction and a bomb bay that could hold 4,800
pounds (2,177 kilograms) of bombs. It was heavily armed with a gun
turret in the nose and three rounded windows (blisters) for gunners on
the sides and bottom of the plane. When it rolled out on July 28, 1935,
a Seattle Times reporter nicknamed it the "Flying Fortress" because of
its heavy armament.
Crew of the Boeing B-17
Memphis Belle at an airbase in England during World War II.
After
three weeks of testing, the Flying Fortress flew non-stop from the Boeing
factory in Seattle to Wright Field, Ohio, overshadowing the Douglas
Aircraft entry, the twin-engine B-18. But tragedy struck on the
Fortress’s second air corps test, when the plane crashed due to pilot
error, killing two. The Flying Fortress seemed to have no future as the
air corps placed orders for the Douglas B-18.
Over
the next winter, Boeing received only a few orders for the Flying
Fortress, then designated the YB-17. Twelve planes were delivered to the
2nd Bomb Group in December 1936, where they were used to make historic
flights, including record-breaking goodwill tours to South America.
Despite their excellent safety record, however, Congress opposed
spending so much money on a large bomber.
Then
Germany invaded Poland on September 1, 1939, and President Franklin
Roosevelt mobilized the country for war. Boeing received a contract for
38 B-17Cs (the blisters were replaced with flat glass and self-sealing
fuel tanks were added). Over the next six years, Boeing built more than
12,000 B-17s for the USAAF. Production demands meant that the government
needed Douglas and Lockheed to build B-17s as well.
As the
United States went to war, crews were equipped with B-17Es and B-17Fs.
(The B-17E added a Sperry ball turret in the front and a remote turret
in the belly; and redesigned the tail assembly to include a tail gunner
position; the B-17F made 300 further small changes, including adding a
one-piece, clear moulded-plastic nose.) These planes arrived in North
Africa, the Pacific, and England, where they formed the nucleus of the
8th Air Force. The B-17s proved essential to success in Europe,
delivering half of all bombs dropped in that theatre.
The
men who flew the Flying Fortress loved their plane and felt it was good
to them. The solid plane endured a lot of punishment, often limping back
to base when a lesser bomber would have crashed. And for the military,
it was an important symbol. General Henry "Hap" Arnold called it "Air
Power that you could put your hand on" and predicted that it was only
the first of many great American bombers.
That
next great bomber was already being built. In 1939, Arnold formed a
special board, named the Kilner Board, to produce a five-year plan for
research and development in the Air Corps. Among its findings was the
need for a long-range bomber with twice the range of the B-17. As the
war in Europe began, the possibility that all air operations on the
continent would need to originate in the United States began to seem
real. Captain Donald Putt, a test pilot, was asked to write the
requirements for such a plane. He stipulated a four-engine airplane with
a range of 5,333 miles (8,583 kilometres) and a speed of 400 miles per
hour (644 kilometres per hour) carrying a one-ton bomb load.
By the
time Boeing received these requirements, it had already developed the
plane. Because of the company’s close relationship with the Air Corps,
it had predicted that such a plane would be required and had already
been developing the Model 345 before Congress had even approved the
appropriation. Boeing won the contract to build 250 B-29s on May 4,
1941, with the first plane scheduled for completion by August 1942. When
the United States declared war, that order was expanded to 500.
The
plane that Boeing built, eventually nicknamed the "Superfortress,"
incorporated all the technological advances of the previous decade. A
special wing, the 117, was developed to reduce drag, increase high-speed
manoeuvrability, and allow low-speed takeoffs and landings. It was the
first bomber to be pressurized, with the front cabin connected to the
one in the rear by a pressurized tunnel that went over the bomb bays.
There was a remote-controlled gunnery system designed by General
Electric that controlled four turrets, and the tail turret was manned
separately. Its air-cooled Wright engines generated 2,200 horsepower
(1,641 kilowatts), and it could fly at 360 to 380 miles per hour (579 to
612 kilometres per hour) with a range of approximately 5,725 miles
(9,213 kilometres).
On
September 21, 1942, the XB-29 made its first flight. For the first two
test flights, the plane flew satisfactorily, and Donald Putt claimed it
was easier to fly than the B-17. Problems soon arose, however. Parts
malfunctioned. Engines began to catch fire. Yet adjustments were made
and testing continued.
Then
disaster hit. During a test flight on February 18, 1943, an engine fire
spread into the wings, forcing the plane to crash into a meat packing
plant, killing the crew of eleven and 20 on the ground. Many, including
President Roosevelt, wanted to end the B-29 program right then. But Hap
Arnold, for whom the B-29 had become a pet project, held an
investigation and found that the problem was with the manufacture of the
engines. The B-29 program was labelled a "special project," which gave
the USAAF full control over all facets of the development--from flight
tests, production, and modifications to the training of crews. Based at
the Boeing plant in Kansas, the project was devoted to getting the plane
ready for action with the 20th Air Force in China by January 1944. The
deadline was met, and the first B-29 mission was flown from India on
June 5, 1944, against Japanese-held Bangkok. When the Marianas Islands
were recaptured in October, the 20th Air Force was relocated there. They
were given as many B-29s as possible, since Japan was within flying
range of the plane.
The Boeing B-29 "Super Fortress"
of World War II.
Under
the leadership of its commander, General Curtis LeMay, the 20th Air
Force used B-29s in an intensive bombing campaign against Japan that
included traditional and incendiary bombs. As many as 300 bombers were
used for each mission, a number that doubled the following summer. As
the threat from enemy fighters decreased, the armament was stripped from
the planes to allow more weight for bombs. The firestorms created by the
incendiary bombs became so intense that the silver planes returned to
base black with soot. And on August 6, 1945, the B-29 Enola Gay dropped
the first nuclear bomb on the city of Hiroshima, followed three days
later by a second bomb dropped by the B-29 Bock’s Car on Nagasaki. The
Japanese surrendered a week later.
Although many credited the nuclear bomb with ending the war, the bomb
never could have been dropped without the range and carrying capacity of
the B-29. When the earlier B-17s returned from the war, they ended up in
bone-yards in the desert, whereas the number of B-29s in service did not
decrease. While Japan signed the surrender on the USS Missouri, 500
Superfortresses flew overhead as a show of force. In the weeks after the
war, it flew "Missions of Mercy"--searching for and dropping supplies on
prisoner of war camps.
In
1946, the plane was mobilized to participate in nuclear testing at
Bikini Atoll. And on June 25, 1950, the day the Korean War began, four
B-29s from Guam were sent to drop bombs on the invading North Koreans.
But by then, they were already obsolete--no match against jets--and they
were used mainly for reconnaissance. The plane that had delivered the
first nuclear bomb and had formed the backbone of the United States
nuclear weapons delivery command was retired less than a decade after
its dramatic debut.