Boeing B29 Super Fortress
XB-29, Boeing Model 345, was the first accepted prototype or experimental model delivered to the Army Air Corps, incorporating a number of improvements on the design originally submitted, including more and larger guns and self-sealing fuel tanks. Two aircraft were ordered in August 1940, and a third was ordered in December. A mockup was completed in the spring of 1941, and it first flew on September 21, 1942.
Testing continued until February 18, 1943, when the second prototype crashed. Flown by Boeing's chief test pilot, Edmund T. "Eddie" Allen on a two-hour powerplant performance test, leaking fuel from a filler cap in the wing leading edge ran down inside the leading-edge and ignited, spreading to the engines. Due to the much reduced power, the aircraft, unable to climb, crashed into the Frye meat-packing plant, demolishing the majority of the packing plant and killing all eleven crew, 22 employees at the plant and one fireman.[5] The crash killed many élite Boeing personnel involved in the design; the pilot, Allen, was chief of the Research Division. After the crash, the United States Army Air Forces and a congressional committee headed by then-Senator Harry S. Truman investigated the B-29 program, issuing a scathing report, prompting the Army Air Forces to take control of the program.
YB-29 was an improved XB-29 and 14 were built for service testing. Testing began in the summer of 1943, and dozens of modifications were made to the planes. The engines were upgraded from Wright R-3350-13s to R-3350-21s. Where the XB-29 had three-bladed props, the YB-29 had four-bladed propellers. Various alternatives to the remote-controlled defensive systems were tested on a number of them, particularly the fourth one delivered. After alternative arrangements had been fully tested, defensive armament was standardised at ten .50-calibre machine guns in turret-mounted pairs. The YB-29 also featured a better fire control system.[6]
The B-29 was the original production version of the Superfortress. Since the new bomber was urgently needed, the production design was developed in tandem with the service testing. In fact, the first B-29 was completed only two months after the delivery of the first YB-29. 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.
The B-29A was an improved version of the original B-29 production model. This is the definitive wartime variant of the B-29. All 1,119 B-29A's were built at the Boeing plant in Renton, Washington, formerly used by the United States Navy.
Enhancements made in the B-29A included a better wing design and defensive modifications. Due to a demonstrated weakness to head-on fighter attacks, the number of machine guns in the forward dorsal turrets was doubled to four. Where the wings of previous models had been made by the sub-assembly of two sections, the B-29A wing was built up from three. This made construction easier, and increased the strength of the airframe. The B-29A was produced until May 1946, when the last aircraft was completed. It was much used during the Korean War, but was quickly phased out when the jet bomber (B-47 Stratojet) became operational.
Washington B Mk 1 – This was the service name given to 88 B-29As supplied to the Royal Air Force.
The B-29B was a modification used for low-level raids, designed with the intent of firebombing Japan. Since fighter opposition was minimal over Japan in late 1944, many of the Army Air Force leadership — most notably Curtis LeMay, commander of the XXI Bomber Command — felt that a (lighter) faster bomber would better evade Japanese flak.
In the B-29B, as with the atomic raid-dedicated Silverplate versions earlier, all defensive armament was removed except for that in the tail turret. Initially the armament was two .50 in M2/AN machine guns and one 20 mm M2 cannon which was soon changed to three .50 in M2/ANs. The weight saved by removing the gun system increased the top speed from 357 mph to 364 mph (575 km/h to 586 km/h).
Also incorporated on this version was an improved APQ-7 "Eagle" bombing-through-overcast radar that was fitted in an airfoil-shaped radome under the fuselage.[10]
The B-29C was a modification of the B-29A re-engined with improved Wright R-3350 engines. The Army Air Force originally ordered 5,000, but cancelled its request when World War II ended and none were built.[11]
B29 with Grand Slam Bombs
Testing continued until February 18, 1943, when the second prototype crashed. Flown by Boeing's chief test pilot, Edmund T. "Eddie" Allen on a two-hour powerplant performance test, leaking fuel from a filler cap in the wing leading edge ran down inside the leading-edge and ignited, spreading to the engines. Due to the much reduced power, the aircraft, unable to climb, crashed into the Frye meat-packing plant, demolishing the majority of the packing plant and killing all eleven crew, 22 employees at the plant and one fireman.[5] The crash killed many élite Boeing personnel involved in the design; the pilot, Allen, was chief of the Research Division. After the crash, the United States Army Air Forces and a congressional committee headed by then-Senator Harry S. Truman investigated the B-29 program, issuing a scathing report, prompting the Army Air Forces to take control of the program.
YB-29 was an improved XB-29 and 14 were built for service testing. Testing began in the summer of 1943, and dozens of modifications were made to the planes. The engines were upgraded from Wright R-3350-13s to R-3350-21s. Where the XB-29 had three-bladed props, the YB-29 had four-bladed propellers. Various alternatives to the remote-controlled defensive systems were tested on a number of them, particularly the fourth one delivered. After alternative arrangements had been fully tested, defensive armament was standardised at ten .50-calibre machine guns in turret-mounted pairs. The YB-29 also featured a better fire control system.[6]
The B-29 was the original production version of the Superfortress. Since the new bomber was urgently needed, the production design was developed in tandem with the service testing. In fact, the first B-29 was completed only two months after the delivery of the first YB-29. 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.
The B-29A was an improved version of the original B-29 production model. This is the definitive wartime variant of the B-29. All 1,119 B-29A's were built at the Boeing plant in Renton, Washington, formerly used by the United States Navy.
Enhancements made in the B-29A included a better wing design and defensive modifications. Due to a demonstrated weakness to head-on fighter attacks, the number of machine guns in the forward dorsal turrets was doubled to four. Where the wings of previous models had been made by the sub-assembly of two sections, the B-29A wing was built up from three. This made construction easier, and increased the strength of the airframe. The B-29A was produced until May 1946, when the last aircraft was completed. It was much used during the Korean War, but was quickly phased out when the jet bomber (B-47 Stratojet) became operational.
Washington B Mk 1 – This was the service name given to 88 B-29As supplied to the Royal Air Force.
The B-29B was a modification used for low-level raids, designed with the intent of firebombing Japan. Since fighter opposition was minimal over Japan in late 1944, many of the Army Air Force leadership — most notably Curtis LeMay, commander of the XXI Bomber Command — felt that a (lighter) faster bomber would better evade Japanese flak.
In the B-29B, as with the atomic raid-dedicated Silverplate versions earlier, all defensive armament was removed except for that in the tail turret. Initially the armament was two .50 in M2/AN machine guns and one 20 mm M2 cannon which was soon changed to three .50 in M2/ANs. The weight saved by removing the gun system increased the top speed from 357 mph to 364 mph (575 km/h to 586 km/h).
Also incorporated on this version was an improved APQ-7 "Eagle" bombing-through-overcast radar that was fitted in an airfoil-shaped radome under the fuselage.[10]
The B-29C was a modification of the B-29A re-engined with improved Wright R-3350 engines. The Army Air Force originally ordered 5,000, but cancelled its request when World War II ended and none were built.[11]
B29 with Grand Slam Bombs