Boeing B-29 Superfortress

From The Air Combat Wiki

Contents 1 Fighter Ace Screenshots 2 Fighter Ace Ratings 3 Fighter Ace Performance 4 Historical Statistics 5 Strengths 6 Weaknesses 7 History 8 Sources 9 See Also

Fighter Ace Screenshots

Fighter Ace museum screenshot by Doug@HQ	Fighter Ace museum screenshot by Doug@HQ	Fighter Ace museum screenshot by Doug@HQ	Fighter Ace museum screenshot by Doug@HQ
Fighter Ace museum screenshot by Doug@HQ	Fighter Ace museum screenshot by Doug@HQ	Fighter Ace museum screenshot by Doug@HQ

Fighter Ace Ratings

Durability: 10

Speed: 6

Maneuverability: 1

Firepower: n/a

Climb Rate: 1

Ground Attack: 10

Fighter Ace Performance

Top Speeds						Climb Rates
	Sea Level	4921' 1500m	9843' 3000m	19685' 6000m	Best Speed	Best IAS	to 1000m	to 3000m	to 6000m
mph	310	321	330	347	347@ 19685'	155 mph	1:58	5:44	10:56
mph WEP	314	324	334	351	351@ 19685'
kph	499	516	531	559	559@ 6000m	249 kph
kph WEP	506	522	537	564	564@ 6000m

Historical Statistics

Service Date: March 1944

Defensive Guns: 2x Browning M2 .50 cal machine guns with 1000 rpg in the forward upper turret, 2x Browning M2 .50 cal machine guns with 1000 rpg in the forward lower turret, 2x Browning M2 .50 cal machine guns with 1000 rpg in the rear upper turret, 2x Browning M2 .50 cal machine guns with 1000 rpg in the rear lower turret, 2x Browning M2 .50 cal machine guns with 1000 rpg

Ordnance: 4x 4000 lb or 8x 2000 lb or 12x 1000 lb or 40x 500 lb bombs

Engine(s): 4x Wright Cyclone R-3350-23 eighteen cylinder air cooled radial engines, each with two General Electric B-11 turbosuperchargers, rated at 2200 hp at 2800 rpm for take-off and with a war emergency rating of 2300 hp at 25,000 ft

Int Fuel Capacity: 49,008 lbs (22,230 kg)

Ext Fuel Capacity: none

Maximum Speeds: 306 mph (492 kph) at sea level, 357 mph (575 kph) at 30,000 ft (9,144 m)

Initial Climb Rate: 920 ft/min (280 m/min)

Ceiling: 33,600 ft (10,241 m)

Empty Weight: 74,500 lbs (33,793 kg)

Normal Loaded Weight: 120,000 lb (54,431 kg)

Maximum Loaded Weight: 135,000 lb (61,235 kg)

Wing Area: 1736 sq ft (161.27 sq m)

Wing Loading: 69.1 lbs/sq ft (337.5 kg/sq m)

Strengths

Durability: The B-29 is the most durable aircraft in the Fighter Ace inventory and capable of withstanding the greatest amount of damage.

Bomb Load: The Superfortress can carry up to 20,000 lbs of bombs, the largest loadout of any plane in the Fighter Ace inventory.

Defense: With four power turrets on the fuselage and a tail turret, each with a pair of .50 cal machine guns, the Superfortress can defend itself from all angles of approach.

Range: The huge fuel load of over 8000 gallons gives the B-29 one of the longest combat ranges of any plane in the Fighter Ace inventory.

Weaknesses

Maneuverability: With a loaded weight of about 60 tons and a wing loading of over 69 lbs/sq ft, the Superfortress has heavy and sluggish controls.

History

The Boeing B-29 Superfortress was the culmination of Boeing piston-engined heavy-bomber design efforts going back to the XB-15. Boeing first began experimenting with a pressurized bomber on the Model 316, a four-engined design derived from the XB-15, with the primary difference being a relocation of the wing from the low to the high position and use of tricycle landing gear. To solve the power definciency of the XB-15, the Model 316 used four of the new 2000 hp Wright Duplex-Cyclone R-3350, 18-cylinder radial engines.

In 1938 Boeing revisited the pressurization feature in the Model 322, a design study based on the B-17. The Model 322 resembled the Model 307 Stratoliner with a new large-diameter circular fuselage, coupled with the standard B-17 wings and tail. The 322 also used a tricycle landing gear arrangement and used four Pratt & Whitney R-2180 radial engines. Due to the pressurization feature, only four gun positions were installed, and the Model 322 had an estimated top speed of 307 mph at 25,000 ft, with a bomb load of 9,928 lbs. Due to a lack of public funding the US Army declined to accept the project, but Boeing continued development with their own money.

The next stage of development was the Model 333, which was originally intended to use Allison V-1710 inline engines in linked pairs. Additionally, the pressurization system was broken into two compartments, one in the fore end of the fuselage and the other in the aft section. These were linked with a small crawl tube placed over the bomb bay area, which is the same configuration eventually used on the B-29. The Model 333A followed soon thereafter with the inline engines replaced by Pratt & Whitney radial engines mounted horizontally inside the wings to reduce expected drag.

The Model 333B was finalized in February 1939 with the use of four 1800 hp Wright R-1800 radial engines mounted horizontally within a thick, 111 foot long wing. Gross weight was calculated at 52,180 lbs and it had an estimated top speed of 364 mph at 20,000 ft. However, the thick wing produced too much drag and the plane was estimated to have a range of only about 2500 miles with a 2000 lb bomb load, which was a distinct step backwards from previous design studies.

The Model 333B was followed in March 1939 with the Model 334, which had the wingspan extended to 120 feet to provide sufficient additional fuel for a range of 4500 miles. Using a twin rudder/fin assembly the Model 334 was projected to have a gross weight of 66,000 lbs and a maximum bomb load of 7830 lbs. Further evolution of the project resulted in the Model 334A in June 1939 in which the engines-inside-the-wings concept was abandoned. Traditional engine nacelles were fitted to a much thinner, high-aspect wing with a wingspan of 135 ft. The tail section utilized a large, single tail/fin assembly and the design was so promising that Boeing proceeded to build a mock-up at their own expense in December 1939.

Meanwhile, the Model 341 was begun in August 1939, which employed a new high-lift aerofoil for a high aspect-ratio wing with a span of 124 ft 7 in. Despite the use of smaller, 2000 hp Pratt & Whitney R-2800 engines, the top speed was estimated to be 405 mph at 25,000 ft. Gross weight was estimated at 85,672 lbs and range was an ocean spanning 7000 miles with a 2000 lb bomb load, while a maximum load of 10,000 lbs could be carried over shorter distances.

On 10 November 1939 General Hap Arnold requested permission to issue a specification for a new "superbomber" to replace the existing B-17 and B-24 designs. Permission was granted on 2 December 1939 and he issued design specification R-40B to Boeing, Lockheed, Douglas and Consolidated on 29 January 1940. The spec called for a bomber with a top speed of 400 mph and a range of 5333 miles with a bomb load of 2000 lbs. The design spec was almost immediately ammended with a requirement for additional defensive armament, self-sealing fuel tanks, and additional armor plating.

To meet this requirement, Boeing took their Model 341 design and scaled it up. The new Model 345 design had the R-2800 engine replaced with the more power R-3350s and the wing was extended to over 141 feet in length. Double-wheeled main landing gear was employed to disperse the gross weight more evenly and the main gear was intended to fold backward into the inboard engine nacelles rather than sideways into the wing. Range was the same as in the Model 341, but the maximum bomb load was increased to 16,000 lbs. Defensive armament was upgraded from six flexibly mounted .50 cal machine guns to four remotely-operated power turrets, each with two .50 cal machine guns, and a manually-operated tail turret with two .50 cal machine guns and a single 20mm cannon. Boeing unveiled their design on 11 May 1940, the day after German troops marched into France, and it received the designation XB-29 from the Air Corps on 27 June 1940.

Lockheed's Model 51-81-01 design, assigned the designation XB-30, was basically an armed version of what would eventually become the Constellation air liner. The Douglas Model 332F was given the designation XB-31 and the Consolidated Model 33 was designated XB-32. Of the three additional designs, only the Consolidated XB-32 was produced as the B-32 Dominator, with a limited production run of 116 machines.

The Army placed an order for two XB-29 prototypes based on the Model 345 design, as well as two XB-32 prototypes, on 24 August 1940. A third XB-29 prototype was ordered on 14 December 1940, along with an additional airframe for static testing, and a full-scale wooden mock-up was built by 7 April 1941. Based on the mock-up an order was placed on 17 May 1941 for 14 YB-29 service test aircraft and 250 full production B-29s with the official name "Superfortress". Following the Japanese attack on Pearl Harbor, the order was doubled to 500 machines in January 1942 and the USAAF announced that it would be built under license by Bell Aircraft, North American Aviation and the Fisher Body Division of General Motors.

The first of the two new bombers to fly was the Consolidated XB-32, which took to the air on 7 September 1942. The first prototype XB-29-BO, tail number 41-002, was completed on 21 September 1942 and made its first flight at 3:40 pm that day from Boeing Field with Edmund "Eddie" Allen at the controls. The prototype was refined with from the original Model 345 design with a lengthened nose section, resulting in overall length being increased from 93 ft to 98 ft 2 in. Considerable engineering work had gone into the design of the engine nacelles, which had to house the Wright Cyclone R-3350-13 28-cylinder engines plus two superchargers for each. Additionally, the inboard nacelles had to house the main landing gear. The final result was the most efficient and cleanest engine nacelles produced up to that point, with more air passing through the engine than had ever before been possible.

The wings were fitted with Fowler-type flaps, which increased wing area by about 20% when fully extended. The tail section, which was the same size and shape as that used on the B-17 from the "E" model onwards, had a large dorsal extension to improve lateral stability, and the bomb bay was redesigned to carry 2000 lb bombs and a large number of smaller bombs, with a maximum capacity of 20,000 lbs. Overall combat weight was a whopping 105,000 lbs! By the time the first XB-29 was flown, the Army was committed to the project with tooling well under way for an advanced order of 1,664 aircraft and over $3 billion had already been invested in the project.

During testing the engines suffered persistent overheating and engine fires were frequent. On 18 February 1943 a fire broke out on prototype #41-003, which could not be extinguished. The fire burned through the wing main spar on the landing approach and the wing failed, causing the plane to crash into a Boeing factory building, which killed test pilot "Eddie" Allen, 11 of Boeing's most experienced Superfortress specialists and over 20 additional workers.

Meanwhile, because all exising Boeing plants were dedicated to production of B-17s, a new plant was built in Wichita, Kansas solely for B-29 production. Other new factories were also built by Boeing at Renton, Washington, by Bell at Marietta, Georgia, and by the Glenn Martin company in Omaha, Nebraska, which had replaced the Fisher Body plant intended for Cleveland. Ohio. An extensive series of sub-contractors were set up with major airframe components being built by Fisher Body, Chrysler, Hudson, Goodyear, Briggs, Murray, and Cessna. Each B-29 consumed sufficient material to build eleven P-51 Mustang fighters!

The third XB-29 prototype (51-18335) was completed at Boeing's Seattle plant in June 1943 and immediately began flight testing. Incorporating extensive engine and equipment revisions, it was soon delivered to the Army Air Force for armament and accelerated flight testing. Meanwhile, the first YB-29 (41-36954) rolled off the assembly lines at the Wichita plant on 15 April and was flown for the first time on 26 June 1943.

The 58th Bombardment Wing (VH) became the first B-29 group when it was formed on 1 June 1943 at Bell's Marietta factory and by July a total of seven YB-29s had been delivered and assigned to new Very Heavy Bombardment (VHB) training squadrons. Wing Headquarters was re-established at Salina, Kansas on 15 September 1943 and was initially composed of the 40th, 444th, 462nd, 468th and 472nd Bombardment Groups (VH). The XX Bomber Command was formed on 27 November 1943 at Salina and a second Very Heavy Bombardment Wing, the 73rd, was created with four more groups intended to use the second batch of 150 Superfortresses to be produced.

Meanwhile, along with the rollout of the first production B-29 on 7 October 1943, the flight characteristics of the B-29 had been finalized and approved by the AAF. The primary change in the production version was the adoption of a four-bladed Hamilton Standard prop with a diameter of 16 ft 7 in, but other changes included the use of General Electric power turrets replacing the original Sperry models and rounded sighting domes on the plane's flanks in place of the previous teardrop-shaped blisters. However only one B-29 existed for every twelve crews, so B-26 Marauders and B-17 Flying Fortresses were used for initial crew training. Over 150 Superfortresses had been promised to be delivered by early 1944, but the program was far behind schedule and FDR's promise to Chiang Kai-shek to begin B-29 operations in China by 15 April 1944 was in jeopardy.

Because of the accelerated production program, newly built Superfortresses lacked many of the latest developments and, rather than cause delays in production, it was decided that the necessary modifications would be made at the Wing level in Kansas before the planes embarked for overseas duty. Over 54 major modifications, and a total of 9000 faults of all kinds, needed to be fixed before they could be considered combat ready by early March none of the planes were ready for deployment. At this point General Hap Arnold stepped in and reorganized the upgrade program using civilian workers drafted from the Seattle and Wichita factories. Between 10 March and 15 April 1944 all necessary modifications were made in a crash program that became known as the "Battle of Kansas".

Finally, on 26 March 1944 the first B-29s had been made ready for overseas deployment and left for the Far East. However, they were first flown to England in hopes that the Axis would think they were intended for the European theater. From there they flew to bases in North Africa. They were held up in Cairo for a week while engine overheating problems were solved by adding engine baffles and rerouting oil lines. By 15 April 1944 a total of 32 B-29s were on the ready line at Kharagpur, India and by the end of the month over a hundred were in place. By 26 April 1944 the first B-29s were flown over the Hump and landed at Kwanghan, China. They had to fly in their own supplies and it took over 12 gallons of fuel to deliver just a single gallon to Kwanghan for combat duties. The first combat encounters occured over the Hump on these supply flights when a single Ki-43 Oscar jumped one of the inbound B-29s. Hits were scored on both aircraft and, although the four power turrets jammed, the tail gunner claimed a victory over the attacking fighter.

The first combat mission took place on 5 June 1944 when Colonel Jack Harmon led a force of 100 B-29s from Kharagpur to bomb the Makasan Rail Yards in Bangkok, Thailand. Only 80 of the bombers reached their target as 20 either turned back with mechanical problems or crashed enroute. They remaining planes bombed through overcast and later reconnaissance revealed that only 18 bombs had hit their target. Ten days later 50 Twentieth Bomber Command B-29s made their first attack against the Japanese homeland when they hit the Imperial Iron and Steel Works at Yawata at night. Seven of the attacking B-29s were lost, but only one was to enemy action, while the target suffered little damage at all. A total of 72 missions were flown by Twentieth Bomber Command B-29s, one of which was the longest bombing mission of the war when 31 B-29s took off from China Bay, Ceylon and bombed the oil refineries at Palembang, Sumatra 1950 miles away.

With the capture of Saipan in the Marianas the Twenty-First Bomber Command was formed and the first B-29 to arrive at Isley Field was Joltin' Jose-The Pacific Pioneer, flown by General Haywood "Possum" Hansell, on 12 October 1944. They made their first attack on 28 October 1944 when a force of 18 B-29s attacked the Japanese submarine pens on Truk Island. On 24 November 1944 a force of 111 B-29s from the 21st Bomber Command made their first attack on the Japanese mainland when they hit the Musashino aircraft factory in Tokyo. The 20th Bomber Command was dissolved in March 1945 and the 58th Bomb Wing was transferred to Saipan to join the 21st Bomber Command, bringing their total number of groups to 20.

General Curtis Lemay took command of B-29 operations in the Marianas in January 1945 and, after reviewing the bombing results against Japanese industrial targets, ordered a change in tactics in March 1945 from high-altitude daylight precision attacks to low-altitude night area bombing against Japanese civilian targets. On 9 March 1945 a force of 334 B-29s burned out 16 square miles from the heart of Tokyo, killing more than 80,000 civilians in a single night. Noting that the enemy air defenses at night were almost non-existent, Lemay ordered all defensive armament removed, except the two .50 cal machine guns in the tail. With the weight savings, the planes could carry heavier bomb loads and could wreak even more destruction. Typical tactics involved the use of pathfinder aircraft carrying 180 70-lb M47 Napalm bombs followed by the main force with each plane carrying 24 500-lb clusters of M69 oil incendiary bombs, with over 8000 such bombs being deployed per square mile. In just three months of such operations the cities of Tokyo, Nagoya and Yokohama had been almost completely burned out.

In mid-1944 several B-29s were modified into F-13A photo-recon aircraft by installing long-range fuel tanks in the bomb bay and numerous K-18 and K-22 cameras.

The B-29A was produced by Boeing at their Renton, Washington plant and included several minor modifications. The most visable of these was the a change to the forward upper turret that increased the armament from two to four .50 cal machine guns, while the tail turret had the 20mm cannon removed. Other changes included a single-piece wing center section, which was stronger, easier to manufacture and easier for field maintenance crews to replace, but at the cost of a slight reduction in fuel capacity. The B-29As were powered by either the R-3350-57 or -59 engines and 1,119 were constructed.

With Lemay's change in tactics the Bell/Marietta plant started producing the B-29B, which had all the upper and lower fuselage gun turrets removed and the 20mm cannon removed from the tail turret. They also had the AN/APG-15 fire-control radar installed with its small, bell-shaped antenna, while some mounted the AN/APG-7 EAGLE radar "wing", which gave bomardiers better definition of ground targets for bombing at night and through overcast. Each B-29B was powered by R-3350-51 engines and the increase in power, coupled with the reduction in weight, increased their maximum tp 367 mph at 30,000 ft. Their maximum fuel load was 6923 gallons and they could carry a 16,000 lb bomb load to a range of about 2600 miles. A total of 329 B-29Bs were built by Bell.

By the time the war ended, the 21st Bomber Command had flown 190 combat missions from their bases in the Marianas. The last combat mission flown was on 14 August 1945 when 741 B-29s hit targets all over Japan. Their next mission was humanitarian in nature, flying supplies on 27 August 1945 to drop to POW camps in Japan. Final statistics for the 21s Bomber Command included 34,000 B-29 sorties flown, 160,000 tons of bombs dropped, and only 371 B-29s lost.

Meanwhile, 17 B-29s had been drawn from the production line of the Martin/Omaha plant at random intervals during the -35, -40, -45 and -50 block and were assigned to the new 393rd Bombardment Squadron (VH) of the 509th Composite Group formed at Wendover Field, Utah on 17 December 1944 under the command of Colonel Paul W Tibbets. This group had been formed for the sole purpose of developing tactics and eventually dropping the first atomic bombs, which were concurrently in development. Training was conducted with inert bombs of various sizes to test ballistics and long-range missions were flown from Batista Field, Cuba.

The atomic bombers had been heavily modified for their mission. Externally, they resembled a standard B-29B with all but the tail guns removed, but internally they were quite different. The engines had been modified to use fuel-injection and Curtiss-Electric propellors had been installed. Fairings were mounted over the gun sighting blisters and the bomb mounting gear was modified to accept the new bombs, with a new rack, hoist assembly, sway braces, shackles and release units, and new bomb bay doors. In May the group flew its B-29s to Tinian in the Marianas. From here they continued to fly training missions as well as participating in a few conventional bombing missions over Japan for target familiarization. Test missions were conducted using a single 10,000 lb bomb shaped like the forthcoming atomic bombs.

The first atomic attack took place on 6 August 1945 against the Hiroshima, which was the largest unbombed Japanese city. Seven B-29s were designated for the mission, one as a spare on standby at Iwo Jima, three were designated for weather recon at the three possible targets, two were for observation with cameras and recording equipment, and the last was the Enola Gay with Colonel Tibbets at the controls. Additionally a pair of F-13As were designated for post-attack target recon and several specially equipped B-29s, the forerunners to the "Superdumbo" rescue planes, were designated for air-sea rescue duties in case any of the planes were brought down.

The second attack took place three days later on 9 August 1945 against Nagasaki. The plane was piloted by Major Charles W Sweeney, who had flown one of the observation flights on the previous attack. However, his plane, "The Great Artiste" was still fitted with scientific equipment and so he flew the "Bockscar", which was normally assigned to Captain F. Bock. The Nagasaki bomb was dropped by radar through overcast.

During the war a total of 1,620 B-29s had been built by Boeing at their Wichita plant, 204 by Martin at Omaha, 357 by Bell at Maretta, and 1,116 by Boeing at their Renton plant. On VJ day the USAAF had 2,132 Superfortresses on hand.

Combat aircraft had extensive electronic navigation and bomb aiming aids instealled, including Loran, BTO, H2X (later EAGLE), Raven ECM, and Ella IFF. In addition to bombing raids of up to 600 aircraft, B-29s had been used on 1,528 mine laying missions in Japanese coastal waters, planting about 12,000 mines, which were estimated to have accounted for about 800,000 tons of Japanese shipping sunk. Several B-29s had been modified to carry two British Grand Slam bombs under the wing roots for a short-range mission bomb-load of 44,000 lbs.

With the end of the war the intended B-29C, with improved Wright R-3350 engines, was cancelled. However, three B-29As were modified to accept 3000 hp Pratt & Whitney R-4360-33 engines and were redesignated XB-44. Additionally a single YB-29 was modified to take 2600 hp Allison V-3420-11 liquid-cooled engines as the XB-39. These became test beds for what was to become the B-50.

Sources

Angelucci, Enzo and Matricardi, Paolo and Pinto, Pierluigi; Complete Book of World War II Combat Aircraft; Barnes & Nobles, Inc., Rome, Italy; 2001.

Davis, Larry; B-29 Superfortress In Action; Squadron/Signal Publications; 1997.

Donald, David; American Warplanes of World War II; Aerospace Publishing Ltd.; 1995.

Green, William; Famous Bombers of the Second World War, Volume Two, Second Series; Doubleday & Company, Inc, Garden City, NY; 1960.

Guntson, Bill; The Illustrated Directory of Fighting Aircraft of World War II; Salamander Books, London; 1988.

Jane's Fighting Aircraft of World War II; Crescent Books, Avenel, NJ; 1992.

See Also

Fighter Ace Planes Inventory

The Boeing Aircraft Company

Aircraft Manufacturers During World War II