The Boeing B-29 Superfortress is a United States Army Air Forces long range, strategic heavy bomber that was produced in many experimental and production models from 1943 to 1946.

The accident happened when leaking fuel from a filler cap in the wing leading edge ran down inside the leading-edge and ignited.

The fire spread to the engines, and due to the much reduced power, the aircraft, unable to climb, crashed into the Frye meat-packing plant.

[4] Many leading Boeing personnel involved in the design perished in the accident; the pilot, Allen, was chief of the Research Division.

After alternative arrangements had been fully tested, defensive armament was standardised at ten .50-calibre machine guns in turret-mounted pairs.

Forty-six B-29s of this variant, built by the Glenn L. Martin Company at its Omaha plant, were used as the aircraft for the atomic bomb missions, modified to Silverplate specifications.

Due to a demonstrated weakness to head-on fighter attacks, the number of machine guns in the forward dorsal turrets was doubled to four beginning with production block 20.

The Army Air Force originally ordered 5,000, but cancelled its request when World War II ended and none were built.

[11] The B-29D was an improved version of the original B-29 design, featuring 28-cylinder Pratt & Whitney R-4360-35 Wasp Major engines of 3500 hp (2600 kW) each — nearly 60% more powerful than the usual Duplex-Cyclone.

When World War II ended, the B-29D was given the quartet of Wasp Major engines to become the B-50, which served throughout the 1950s in the U.S. bomber fleet.

Stripped of armament, a converted B-29B-55-BA[15] (44-84043)(Bell) designated the XB-29G carried experimental jet engines in its bomb bay, which were extended into the airstream for testing during flight.

Other engine-associated items were also upgraded, including new Curtiss propellers, and 'Andy Gump' cowlings, in which the oil coolers have separate air intakes.

Sixteen B-29s were modified to carry a droppable A-3 lifeboat under the fuselage; redesignated SB-29, they were used mainly as rescue support for air units that flew long distances over water.

With the exception of the forward lower gun turret, all defensive armament was retained; the aircraft additionally carried a variety of radio equipment, provisions, survival kits, and extra crew.

It received its nickname from Dumbo, the Disney character, whose name was given to the aircraft used in previous missions to pick airmen up when they crashed at sea.

The TB-29 was a trainer conversion of B-29 used to train crew for bombing missions; some were also used to tow targets, and the designation included B-29s modified solely for that purpose.

Their most important role was serving as radar targets in the 1950s when the United States Air Force was developing intercept tactics for its fighters.

On 3 September 1949, a WB-29 returning from Yokota AB, Japan, to Eielson AFB, Alaska, recovered radioactive debris in air sampling scoops from the cloud generated by the first atomic bomb test by the Soviet Union on 29 August.

A study for the conversion of B-29s to long-range cruise missiles was conducted by the Air Materiel Command between 1946 and 1950; given the designation MX-767, it was given the codename Project Banshee.

It has since been relocated to Fantasy of Flight's "Golden Hill" storage facility along with the remainder of the disassembled aircraft, awaiting future restoration to flyable status.

Seeking a modern long-range bomber, Joseph Stalin ordered the Tupolev OKB to reverse-engineer the Superfortress.

Although largely identical in appearance to American B-29s, the Tu-4 (NATO reporting name: "Bull") had Soviet-designed defensive guns and had been re-engineered to suit production using material of metric thicknesses, resulting in an aircraft that was slightly heavier and slower than the B-29.

Not only did the Soviet Air Forces have the means to deliver nuclear weapons, but the Tu-4 had sufficient range to reach the United States on a one-way trip.

Although the Tu-4 had never delivered any explosive payload with offensive intent, it influenced Soviet aircraft technology, particularly airframe construction and onboard systems.