B-29 Superfortress | |
---|---|
General information | |
Type | Strategic bomber |
Manufacturer | Boeing |
Status | Retired (see Surviving aircraft) |
Primary users | United States Army Air Forces |
Number built | 3,960 |
History | |
Manufactured | 1943–1946 [1] |
Introduction date | 8 May 1944 |
First flight | 21 September 1942 [2] |
Retired | 21 June 1960 |
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 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 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 was conducted on the XB-29 until February 18, 1943, when the second prototype crashed. The flight was conducted by Boeing's chief test pilot, Edmund T. "Eddie" Allen on a two-hour powerplant performance test. 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. The crash demolished the majority of the packing plant and killed all eleven XB-29 crew, 22 employees at the plant, and one fireman. [4] Many leading Boeing personnel involved in the design perished in the accident; 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.
The 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. [5]
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.
Some 2,513 B-29s were manufactured by Boeing-Wichita (1,620), Bell-Atlanta (357), and Martin-Omaha (536). [6]
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 beginning with production block 20. 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 employed up to, and through, the Korean War, after which it was then quickly phased out when the 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 AN/M2 machine guns and one 20 mm M2 cannon which was soon changed to three .50 in AN/M2s. The weight saved by removing the guns 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]
All 311 B-29Bs were built at the Bell plant in Marietta, Georgia ("Bell-Atlanta").
The B-29C was a modification of the B-29A re-engined with improved Wright R-3350 Duplex-Cyclone engines. 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. It also had a taller vertical stabilizer and a strengthened wing. The XB-44 was the testbed designation for the D model.
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.
A number of B-29s were converted to serve as test beds for new systems. These all received variant designation, even though many existed only as a single converted aircraft.
The XB-29E for fire-control systems (one converted) was a model B-29-45-BW. [13]
The B-29F for cold-weather operation in Alaska were six converted B-29-BWs. [14]
The B-29 was used in the development of jet engines. 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. This plane was used to test the Allison J35, General Electric J47 and J73 jet engines. [16]
The XB-29H to test armament configurations was a converted B-29A. [17]
Experimentation in piston engines continued. Six B-29s (redesignated YB-29J) [18] of various designation were upgraded to R-3350-79 engines. Other engine-associated items were also upgraded, including new Curtiss propellers, and 'Andy Gump' cowlings, in which the oil coolers have separate air intakes. Two were later converted to aerial refueling tanker prototypes, and redesignated YKB-29J. The remainder were used for reconnaissance, and designated RB-29J.
The EB-29 (E stands for exempt), was used as a carrier aircraft in which the bomb bay was modified to accept and launch experimental aircraft. They were converted in the years following World War II. One EB-29 was converted to carry the famous Bell X-1 until it was replaced by a B-50. Another was used to carry and test the XF-85 'parasite fighter'. This fighter was intended to be carried by the Convair B-36 on long-range missions to protect it from Soviet fighters. Another EB-29 was used to carry two EF-84B Thunderjet fighters as part of Project Tom-Tom. All three Tom-Tom aircraft (the B-29 and the two jet fighters) and their crews were lost in a crash on April 24, 1953. [20]
Early B-29/B-29As that were modified for photo reconnaissance carried the F-13/F-13A designations, with "F" meaning 'photo'. The aircraft (118 modified B-29BWs and B-29As) carried three K-17B, two K-22 and one K-18 cameras. Between the end of World War II (1945) and 1948 the designation was changed to FB-29J. In 1948, the F-13/FB-29s were redesignated RB-29 and RB-29A.
Six B-29A/F-13As were modified with the Wright R-3350-CA-2 fuel injected engines and designated at YB-29Js. These were then converted to RB-29Js. [22]
In January 1949, RB-29s were assigned to the 91st Strategic Reconnaissance Wing and moved to Yokota AB, Japan in December 1950; to provide support to the Korean War and attached to the 15th Air Force, Far East Air Force.
The SB-29 'Super Dumbo' was a version of the B-29 adapted for air-sea rescue duty after World War II. 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. The first SB-29s were received by the Air Rescue Service in February 1947. 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. The SB-29 was used operationally throughout the Korean War into the mid-1950s. 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.
The WB-29s were production aircraft modified to perform weather monitoring missions. An observation position was fitted above the central fuselage section. They conducted standard data-gathering flights, including from the UK over the Atlantic. They were also used to fly into the eye of a hurricane or typhoon to gather information. Following nuclear weapons tests, some WB-29s used air sampling scoops to test radiation levels. 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. [23]
In 1951, three B-29s were modified for use in the Airborne Early Warning program. The upper section of the forward fuselage was extensively modified to house an AN/APS-20C search radar, and the interior was modified to house radar and Electronic Counter Measures (ECM) equipment. This development led to production radar picket aircraft, including the EC-121 Warning Star. (×3, converted)
A Soviet-built copy of the B-29, the Tu-4, was used as the platform for a Chinese experimental airborne early warning aircraft, the KJ-1 AEWC, in the 1970s.
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. Flight tests were conducted, however no full conversions were carried out before the project was abandoned. [24]
The U.S. Navy acquired four B-29-BWs from the U.S. Army Air Forces on March 14, 1947. These aircraft were modified for long-range patrol missions and given the designation P2B-1S with Navy Bureau Numbers (BuNo) 84028, 84029, 84030 and 84031.
BuNo 84029, previously AAF Ser. No. 45-21787, [26] was modified to carry the Navy's Douglas D-558-2 Skyrocket high-speed research aircraft. The bomb bay was modified to carry the Skyrocket II under the belly and drop for supersonic speed testing. The first Skyrocket test flight occurred on September 8, 1950, with test pilot William B. Bridgeman, and George Jansen flying the B-29. Scott Crossfield later broke Mach 2 flying the Skyrocket on November 20, 1953; the last Skyrocket flight was in December 1956.
The P2B-1S "mother-ship" was nicknamed Fertile Myrtle and was assigned the NACA number 137. As of May 2013, this aircraft was in the collection of Kermit Weeks at his Fantasy of Flight aviation museum in Polk City, Florida. The forward fuselage section was restored and briefly displayed at the Florida Air Museum in Lakeland, Florida. 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. [27] [28]
BuNo 84030 and 84031 were later modified into anti-submarine patrol bombers and redesignated P2B-2S. [29]
The XB-39 Superfortress was a single YB-29 modified to use water-cooled Allison V-3420-17 Vee type engines. Since the Army Air Force was concerned that problems might develop with their first choice of engine, the Wright R-3350, they contracted General Motors to test a modified aircraft to show that it could still be used if the R-3350 development was not successful. Since the R-3350 did not have significant enough problems to prevent its use, no XB-39s were ordered.
In 1945, three B-29s were forced to land in Soviet territory after a bombing raid on Japan because of lack of fuel. Since the Soviet Union was not at war with Japan at the time, the aircraft and crew were interned. Eventually, the B-29 crew members were returned, but the aircraft remained in Russian hands. Seeking a modern long-range bomber, Joseph Stalin ordered the Tupolev OKB to reverse-engineer the Superfortress.
The resulting aircraft first flew on May 19, 1947, and immediately began series production, totalling 847 Tu-4s. 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. The Tu-4 presented a significant leap forward in Soviet strategic bombing. 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. On October 18, 1951, a Tu-4 was used in the first air-drop test of a Soviet atomic bomb.
The Tu-4 had been phased out of Soviet service by the early 1960s, being replaced by more modern aircraft such as the Tupolev Tu-95. Although the Tu-4 had never delivered any explosive payload with offensive intent, it influenced Soviet aircraft technology, particularly airframe construction and onboard systems. Advanced transport and bomber variants of the Tu-4 design such as the Tu-70, Tu-75, Tu-80, and Tu-85, were developed and built, but none of these achieved series production.
The People's Liberation Army Air Force of China attempted to use the Tu-4 airframe in the KJ-1 AWACS aircraft. [31]
The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 Flying Fortress, the Superfortress was designed for high-altitude strategic bombing, but also excelled in low-altitude night incendiary bombing, and in dropping naval mines to blockade Japan. B-29s dropped the atomic bombs on Hiroshima and Nagasaki, the only aircraft ever to drop nuclear weapons in combat.
The Martin B-10 was the first all-metal monoplane bomber to be regularly used by the United States Army Air Corps, having entered service in June 1934. It was also the first mass-produced bomber whose performance was superior to that of the Army's pursuit aircraft of the time.
The Boeing B-47 Stratojet is a retired American long-range, six-engined, turbojet-powered strategic bomber designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraft. The primary mission of the B-47 was as a nuclear bomber capable of striking targets within the Soviet Union.
A strategic bomber is a medium- to long-range penetration bomber aircraft designed to drop large amounts of air-to-ground weaponry onto a distant target for the purposes of debilitating the enemy's capacity to wage war. Unlike tactical bombers, penetrators, fighter-bombers, and attack aircraft, which are used in air interdiction operations to attack enemy combatants and military equipment, strategic bombers are designed to fly into enemy territory to destroy strategic targets. In addition to strategic bombing, strategic bombers can be used for tactical missions. There are currently only three countries that operate strategic bombers: the United States, Russia and China.
Heavy bombers are bomber aircraft capable of delivering the largest payload of air-to-ground weaponry and longest range of their era. Archetypal heavy bombers have therefore usually been among the largest and most powerful military aircraft at any point in time. In the second half of the 20th century, heavy bombers were largely superseded by strategic bombers, which were often even larger in size, had much longer ranges and were capable of delivering nuclear bombs.
The Convair B-36 "Peacemaker" is a strategic bomber built by Convair and operated by the United States Air Force (USAF) from 1949 to 1959. The B-36 is the largest mass-produced piston-engined aircraft ever built, although it was exceeded in span and weight by the one-off Hughes Hercules. It has the longest wingspan of any combat aircraft. The B-36 was capable of intercontinental flight without refueling.
The Wright R-3350 Duplex-Cyclone is an American twin-row, supercharged, air-cooled, radial aircraft engine with 18 cylinders displacing nearly 3,350 cubic inches (54.9 L). Power ranged from 2,200 to 3,700 hp, depending on model. Developed before World War II, the R-3350's design required a long time to mature, and was still experiencing problems with reliability when used to power the Boeing B-29 Superfortress.
The Consolidated B-32 Dominator was an American heavy strategic bomber built for United States Army Air Forces during World War II, which had the distinction of being the last Allied aircraft to be engaged in combat during World War II; that engagement also resulted in the last American to die in air combat in World War II. It was developed by Consolidated Aircraft in parallel with the Boeing B-29 Superfortress as a fallback design should the B-29 prove unsuccessful. The B-32 reached units in the Pacific only in mid-May 1945, and subsequently saw only limited combat operations against Japanese targets before the formal end of the war on 2 September 1945. Most of the extant orders of the B-32 were canceled shortly thereafter and only 118 B-32 airframes of all types were built.
The Tupolev Tu-4 is a piston-engined Soviet strategic bomber that served the Soviet Air Force from the late 1940s to mid-1960s. The aircraft was a copy of the American Boeing B-29 Superfortress, having been reverse-engineered from seized aircraft that had made emergency landings in the USSR.
The Tupolev Tu-70 was a Soviet passenger variant of the Tu-4 bomber, an unlicensed, reverse engineered copy of the Boeing B-29 Superfortress. Designed immediately after the end of World War II, it used a number of components from Boeing B-29s that had made emergency landings in the Soviet Union after bombing Japan. It had the first pressurized fuselage in the Soviet Union and first flew on 27 November 1946. The aircraft was successfully tested, recommended for serial production, but ultimately not produced because of more pressing military orders and because Aeroflot had no requirement for such an aircraft. A military cargo aircraft version was the Tupolev Tu-75.
The Boeing B-50 Superfortress is an American strategic bomber. A post–World War II revision of the Boeing B-29 Superfortress, it was fitted with more powerful Pratt & Whitney R-4360 radial engines, stronger structure, a taller tail fin, and other improvements. It was the last piston-engined bomber built by Boeing for the United States Air Force, and was refined into Boeing's final such design, the prototype B-54. Although not as well known as its direct predecessor, the B-50 was in USAF service for nearly 20 years.
The Boeing XB-39 Superfortress was a United States prototype bomber aircraft, a single example of the B-29 Superfortress converted to fly with alternative powerplants. It was intended to demonstrate that the B-29 could still be put into service even if the first choice of engine, the air-cooled Wright R-3350 radial engine, ran into development or production difficulties.
The Boeing YB-9 was the first all-metal monoplane bomber aircraft designed for the United States Army Air Corps. The YB-9 was a much enlarged twin-engine development of Boeing's single-engine Model 200 Monomail commercial transport.
The Boeing B-54 was an American strategic bomber designed by Boeing for use by the United States Air Force. Derived from the YB-50C Superfortress, construction of the prototype was canceled before completion, and the aircraft was never flown.
The Boeing KB-29 was a modified Boeing B-29 Superfortress for air refueling needs by the USAF. Two primary versions were developed and produced: KB-29M and KB-29P.
The Battle of Kansas was the nickname for a project to build, modify, and deliver large quantities of the world's most advanced bomber to the front-lines in Europe, and then to the Pacific, although because of delays in production, it was used only in the Pacific. The "battle" began as the first
B-29 Superfortresses rolled off the production lines of the massive new Boeing factory on the prairie near Wichita, Kansas.
The 315th Air Division is an inactive United States Air Force formation. Originally designated the 315th Bombardment Wing, it was activated in July 1944 at Peterson Field, Colorado as a command organization for four very heavy Boeing B-29 Superfortress bombardment groups. It supervised the 16th, 331st, 501st and 502nd Bombardment Groups in the Mariana Islands during the last stages of the Second World War. Its last assignment was with Pacific Air Forces, based at Tachikawa Air Base, Japan, where the division was inactivated in April 1969.
FIFI is a Boeing B-29 Superfortress. It is one of two B-29s in the world flying as of 2024. It is owned by the Commemorative Air Force and is based at the Victor N. Agather Hangar at Dallas Executive Airport in Dallas, Texas.