B-29 Superfortress

Type: Long-range Strategic Heavy bomber
Crew: 10: Pilot, Co-Pilot, Engineer, Bombardier, Radioman, 5 Gunners
Armament: eight .50 cal machine guns (two in each of four power turrets)
three.50 cal machine guns (or two .50 cals and one 20mm cannon) in the tail turret
up to 20,000 lbs. of bombs

Specifications:
Length: 99' 0" (30.18 m)
Height: 29' 7" (9.02 m)
Wingspan: 141' 3" (43.05 m)
Weight: 124,000 lb max at takeoff

Propulsion:
No. of Engines: 4
Powerplant: Wright R-3350-23 Cyclone 18
Horsepower: 2200 hp each

Performance:
Range: 3250 miles (5230 km)
Cruise Speed: 230 mph (370 km/h)
Max Speed: 358 mph (576 km/h)
Ceiling: 31850 ft (9710 m)

The B-29 was manufactured at four main assembly factories: two Boeing plants at Renton, Washington and Wichita, Kansas, a Bell plant at Marietta, Georgia, and a Martin plant at Omaha, Nebraska. Thousands of subcontractors were involved in the project. Because of its highly advanced design, challenging requirements, and immense pressure for production, development was deeply troubled. On 18 February 1943, the second prototype flown by Boeing Chief Test Pilot Eddie Allen crashed during testing due to an engine fire that spread to the wing, killing the entire ten man crew and twenty others in the Frye meat packing plant just north of Boeing Field. Changes to the production aircraft came so often that in early 1944, B-29s would leave the production lines and fly directly to modification depots for extensive rebuilds to incorporate the latest changes. This Battle of Kansas (a trouble-shooting modification program to get four groups ready for combat by 1 January 1944) nearly sank the program, which was only saved by General Hap Arnold's direct intervention. It would still be nearly a year before the aircraft was operated with any sort of reliability.

The most common cause of maintenance headaches and catastrophic failures was the engine. Though the Wright R-3350 Cyclone engine would later become a trustworthy engine, early models had dangerous reliability problems. Many of these problems were caused by the mad rush to put newly constructed B-29s in operation as soon as possible. The early cowl flaps had too much flutter and vibration when open in most of the flight envelope. The compactly arranged 18 radial cylinders overheated because of insufficient flow of cooling air. This caused the valves to unseat.

These weaknesses combined to make an engine that would overheat regularly when the airplane was fully loaded with fuel and bombs. This was especially troublesome during climbs after takeoff. Unseated valves released fuel-air mixtures during engine combustion that acted as a blowtorch against the valve stems. When these burned through the engines disintegrated and caught fire. A fire that was not immediately contained in the forward part of the engine by fire extinguishers became impossible to put out. An accessory housing manufactured of magnesium alloy in the back of the engine would often catch fire and produce heat so intense it burned through the firewall to the main wing spar in no more than 90 seconds, resulting in catastrophic failure of the wing.

This problem would not be fully solved until the aircraft was re-engined after World War II with the more powerful Pratt & Whitney R-4360 'Wasp Major' engine in the B-29D/B-50 program. In the interim, cuffs were placed on propeller blades to divert a greater flow of cooling air into the intakes which had baffles installed to direct a stream of air onto the exhaust valves. Oil flow to the valves was also increased, asbestos baffles were installed around rubber push rod fittings to prevent oil loss, and thorough pre-flight inspections were made to detect unseated valves.

The initial plan, implemented at the direction of President Roosevelt as a promise to China and called Operation Matterhorn, was to use B-29s to attack Japan from four forward bases in Guangxi, southern China, with five main bases in Bangladesh, India, and to attack other targets in the region from China and India as needed. The Chengdu region was eventually chosen over the Guilin region to avoid having to raise, equip, and train fifty Chinese divisions to protect the advanced bases from Japanese ground attack. The XX Bomber Command, initially was intended to be two combat wings of four groups each but was reduced to a single wing of four groups because of the lack of availability of aircraft. This limited the effectiveness of any attacks from China.

This was an extremely costly scheme, as there was no overland connection available between India and China, and all the supplies had to be flown over the Himalayas. B-29s started to arrive in India in early April 1944. The first B-29 flight to airfields in China over the Himalayas ("The Hump") took place on 24 April 1944. The first B-29 combat mission was flown on 5 June,1944, with 77 out of 98 planes launched from India bombing the railroad shops in Bangkok. Five B-29s were lost to non-combat causes.

On 15 June 1944, 47 B-29s launched from Chengdu in China bombed the Imperial Iron and Steel Works at Yawata, Japan. This was the first attack on Japanese islands since the Doolittle Raid in April 1942. The first B-29 combat loss occurred during this raid, with one B-29 destroyed on the ground by Japanese fighters after an emergency landing. Because of the extreme cost of operations, the raids against Japan from Chinese airfields continued at relatively low intensity. Japan was bombed on: 7 July 1944 (14 B-29s), 29 July 1944 (70+), 10 August 1944 (24), 20 August 1944 (61), 8 September 1944 (90), 26 September 1944 (83), 25 October 1944 (59), 12 November 1944 (29), 21 November 1944 (61), 19 December 1944 (36), and for the last time on 6 January 1945 (49). B-29s were withdrawn from airfields in China by the end of January 1945. Throughout this period B-29 raids were also launched from China and India against many other targets throughout Southeast Asia. The entire B-29 effort was gradually moved to the new bases in the Marianas, with the last B-29 combat mission from India flown on 29 March 1945.

The need to use inconvenient bases in China for attacks against Japan ceased after the capture of the Mariana Islands in 1944. On the islands of
Tinian, Saipan, and Guam five major airfields, each constructed as a base for a four-group wing of B-29s, became the launch sites for the large B-29 raids against Japan in the final year of the war. The islands could be easily supplied by ship. The first B-29 arrived on Saipan on 12 October 1944, and the first combat mission was launched from there on 28 October 1944, with 14 B-29s attacking the Truk atoll.

The first mission against Japan from bases in the Marianas was flown on 24 November 1944, with 111 B-29s sent to attack Tokyo. Out of 111 B-29s that took off, seventeen of them had to abort due to the usual engine failures. The remainder approached the target at altitudes of 27,000 - 32,000 feet. For the first time, the B-29 encountered the jet stream, which was a high-speed wind coming out of the west at speeds as high as 450 mph at precisely the altitudes at which the bombers were operating. This caused the bomber formations to be disrupted and made accurate bombing impossible. The Nakajima plant was also clouded over at the time and only 24 of the B-29s dropped their bombs in the right area. The target was barely damaged and one B-29 was rammed by a Japanese fighter and destroyed. It was not a good start.

The Musashi plant was bombed again ten more times over the next few weeks. The results were still disappointing. Only 10% of the damage done by the bombs was actually inside the plant area. 40 bombers had been lost in these eleven raids, many to accidents caused by engine failures. In December 1944 there were a series of raids against the Mitsubishi engine plant at Nagoya. Although some 17% of the facility was gutted, Japanese defenses were becoming more effective and losses to enemy action were now reaching 4 or 5 per mission. The Marianas operation was going the way of Operation Matterhorn with losses being high and not much damage to the enemy being done. Since not very much progress was being made, General Hap Arnold recalled General Haywood Hansell. General Curtis Lemay took over XXI Bomber Command on 20 January 1945.

Lemay analyzed that the Japanese economy was dependent on small cottage industries spread throughout the large cities. Since the previous efforts at high-level precision, daylight bombing of specific targets had failed, LeMay instead proposed to burn out the Japanese cities entirely, destroying the critical industries and the civilian population in the process.

LeMay approach was radically different. The bombers would carry incendiary bombs rather than high explosive bombs. To save fuel and maximize the bomb load, the guns were removed, the B-29s would fly at 5,000 - 7,000 feet instead of 27,000 - 32,000 feet, and each plane would fly directly to the target with no more circling to join up in formation. These measures allowed each B-29 to carry about seven tons of incendiary bombs. They would also go at night since precision was no longer required and because Japanese night fighter forces were not very good.

The results were devastating. On the night of 9-10 March 1945, 279 B-29's bombed Tokyo. A huge firestorm resulted. Sixteen square miles of Tokyo were reduced to ashes and 84,000 Japanese were killed. Similar but less destructive results were obtained in Nagoya, Osaka, and Kobe in the next week. Only twenty B-29s were lost. XXI Bomber Command exhausted its supply of incendiaries for a while. After they were resupplied in April, the B-29s continued the terrible raids with awesome fury. The industrial areas of Tokyo, Nagoya, Osaka, Kawasaki, Kobe, and Yokohama were reduced to ashes. The aircraft engine factories were hit again with incendiary bombing. By mid-April, Japanese aircraft engine manufacturing capability had been wiped out. The incendiary raids continued through June 1945, reducing the six largest cities of Japan to ashes. Kobe was so thoroughly gutted that it was removed from the target list.

Late in 1944, the Army Air Force ordered a special batch of fifteen modified B-29s, called Silverplate models. These planes had no gun turrets except for the tail turret, no armor plate, and new Curtiss electric propellers. These planes were specifically designed to carry one of the two atomic bombs from the Manhattan Project, either Little Boy or Fat Man .

The 509th Composite Group commanded by Colonel Paul W. Tibbetts took possession of these aircraft for the atomic attacks on Hiroshima and Nagasaki. Ten of these aircraft are known to have taken part in what became Special Missions 13 and 16 against Hiroshima and Nagasaki. Enola Gay was modified to drop Little Boy and Bockscar was modified to drop Fat Man. The other aircraft were assigned to perform weather reconnaissance, blast measurement, and strike photography.

On 6 August 1945, the Enola Gay commanded by Colonel Paul W. Tibbetts dropped Little Boy on Hiroshima. Three days later, Bockscar commanded by Major Charles W. Sweeney dropped Fat Man on Nagasaki. The combined shock of the atomic bombs and the Soviet declaration of war on Japan on 8 August 1945 caused Emperor Hirohito to intervene and order the Big Six (Japan's leaders at the Supreme Council for the Direction of the War) to accept the terms for ending the war that the Allies had set down in the Potsdam Declaration. After several more days of behind-the-scenes negotiations and a failed coup d'état, Hirohito gave a recorded radio address to the nation on 15 August 1945 to announce the surrender of Japan.

On 29 July 1944, a B-29 was damaged by flak during a raid on the Showa steel works at Anshan in Manchuria. The crew decided to divert to Vladivostok in the Soviet Union as they were unable to make the trip back to its base in Chengtu, China. Since the Soviet Union was not at war with Japan at the time, both the aircraft and the crew were interned.

On 20 August 1944, a B-29 from Chengtu was forced to divert to the Soviet Union during a raid on Yawata. It crashed in the foothills of Sikhote Alin Range east of Khabarovsk after the crew baled out. The crew was interned.

On 10-11 November 1944 and again on 21 November 1944, B-29s damaged during raids on Kyushu diverted to Vladivostok. The aircraft and crews were interned.

The Soviets were now holding three intact B-29s and four B-29 crews. In January 1945, it was arranged by the Soviets for these four crews to "escape" to the West via Teheran, but their B-29s remained behind.

World War II had been over only for a little over a year when an article appeared in the 11 November 1946 issue of the Berlin newspaper Der Kurier claiming that the Soviet Union was manufacturing a bolt-for-bolt copy of the B-29 in a series of factories located in the Urals. This report was widely disbelieved, since the Soviet Union was at the time thought incapable of manufacturing an aircraft as large and sophisticated as the B-29. It was later discovered that some Soviet agents had been attempting to purchase B-29 tires, wheels, and brake assemblies in the USA making the Der Kurier story more believable.

The presentation to the Soviet Union of three intact B-29s was extremely lucky turn of events, since the Soviet aircraft industry could now overcome the huge technological problems involved in the development of a strategic bomber in a fraction of the time it would have taken to develop a design from scratch. Stalin ordered that the Soviet Union develop a copy of the B-29. The design bureau of Andrie Tupolev was given responsibility for the airframe, while the engine bureau headed by Arkadii Shvetsov was assigned the responsibility of copying the Wright R-3350 Cyclone engine. The Soviet version of the B-29 was assigned the designation Tu-4.

Two of the B-29s were disassembled for detailed evaluation with the third being kept intact for flight testing. The Tu-4 project was well under way by the first quarter of 1945. A factory on the Volga was given the task of building 20 test and evaluation aircraft and two factories behind the Urals were given the responsibility for full-scale production.

The Soviet Tu-4 program continued even after the end of World War II. The first Tu-4 test aircraft was ready by the late summer of 1946. Early test flights turned up problems with the landing gear which forced several wheels-up landings and there were also frequent runaway propellers. The Soviet Union used the metric system so 1/16 inch (1.6 mm) thick sheet aluminum and proper rivet lengths were unavailable. The corresponding metric-gauge metal was thicker so the Tu-4 weighed about 3,100 pounds more than the B-29. This caused the Tu-4 to have less range and payload than the B-29.

The Tu-4 was assigned the code name Bull in the NATO code naming system. The entrance into service of the Tu-4 threw the USAF into a panic, since the Tu-4 had enough range to attack the United States on a one-way suicide mission. Since the Soviets now had a weapon capable of attacking North America, the United States government was forced to develop an extremely costly air-interception capability involving ground radar installations, surface-to-air missiles, and jet interceptor fighters. The United States was in danger of nuclear attack after the development of the Soviet atomic bomb in 1949.

About 1200 Tu-4s were built in the Soviet Union. In the late 1950s, the Soviet Union gradually withdrew the Tu-4 from service and they sent some Tu-4s to China. Some of these were reportedly still in service in China as recently as 1968.

In 1946, the Strategic Air Command acquired many of the B-29 aircraft still in service. These planes were largely antiquated and had seen heavy use during the war. Boeing responded to SAC's need, first with the B-29D, a much-improved model that the new Air Force redesignated as the B-50. The B-50 had 59 percent more power than the original B-29, along with better aerodynamic surfaces, larger flaps, faster-retracting landing gear, and improved hydraulic control systems. It also sported a higher tail that could fold during storage, and a stronger, lighter wing. It also had twelve guns (the original B-29 had ten) and required a crew of twelve. In all, Boeing built 371 B-50s, including 79 B-50As.

With the arrival of the mammoth Convair B-36, the B-29 and the B-50 variant were reclassified as a medium bomber with the new Air Force. The B-50 variant was good enough to handle roles such as air-sea rescue, electronic intelligence gathering, and even air-to-air refueling. The B-50 was replaced in its primary role during the early 1950s by the
Boeing B-47 Stratojet, which was later replaced by the Boeing B-52 Stratofortress. 3,970 B-29s were built before they were retired in 1960. The last B-50 tankers were retired from active service in 1965.

B-50 Specifications

Crew: 8: Pilot, co-pilot, flight engineer, radio/electronic countermeasures operator, two side gunners, top gunner and tail gunner
Length: 99 ft 0 in (30.2 m)
Wingspan: 141 ft 3 in (43.1 m)
Height: 32 ft 8 in (10.0 m)
Wing area: 1720 ft² (159.9 m²)
Empty weight: 84,714 lb (38,506 kg)
Loaded weight: 121,850 lb (55,270 kg) (combat weight)
Max takeoff weight: 173,000 lb (78,470 kg) (max overload weight)
Powerplant: 4× Pratt & Whitney R-4360-35 radial engines, 3,500 hp (2,600 kW) each

Performance

Maximum speed: 394 mph (343 knots, 635 km/h) at 30,000 ft (9,150 m)
Cruise speed: 244 mph (212 knots, 393 km/h)
Combat radius: 2,394 mi (2,082 nmi, 3,855 km)
Ferry range: 7,750 mi[32] (6,739 nmi,12,478 km)
Service ceiling: 36,900 ft (11,250 m)
Rate of climb: 2,200 ft/min (11.2 m/s)
Wing loading: 70.19 lb/ft² (343 kg/m²)
Power/mass: 0.115 hp/lb (193 W/kg)

Armament

Guns:
13× .50 in (12.7 mm) M2 Browning machine guns in 4 × remote controlled and manned tail turret
Bombs:
20,000 lb (9,100 kg) internally
8,000 lb (3,600 kg) on external hardpoints

One B-29 was as used as the "mother" aircraft for the Bell X-1 research aircraft. On 14 October 1947, Captain Charles E. "Chuck" Yeager was dropped in the X-1 from the B-29 and became the first pilot to exceed speed of sound in the X-1.

The US Navy used four B-29s for long-range search missions. The Navy designation P2B-1S was assigned for the Naval B-29.

One P2B-1S was extensively modified to carry the Douglas D-558-II Skyrocket high-speed rocket-powered research aircraft. The first Skyrocket launch took place on 8 September 1950. The Skyrocket piloted by Scott Crossfield exceeded Mach 2 for the first time on 20 November 1953. The last Skyrocket flight took place in December 1956.

The B-29 was first used in normal strategic daylight bombing missions. North Korea's few strategic targets and industries were quickly reduced to rubble. Then the Soviet MIG-15 jet fighter arrived. After the loss of several aircraft, future B-29 raids were restricted to night-only missions. B-29 gunners were credited with shooting down 27 enemy aircraft.

B-29s flew 1,076 days during the 1,106-day air war in Korea, dropping 160,000 tons of bombs on North Korean targets which is a greater bomb tonnage than had been dropped on Japan during World War II. Regardless of the many obstacles they faced, B-29 crews destroyed industrial and military strategic targets in North Korea and supported UN ground troops. The Far East Air Force lost 1,406 aircraft and suffered 1,144 men killed and 306 wounded during the war. Thirty Far East Air Force men who had been declared missing were eventually returned to military control, 214 POWs were repatriated under the terms of the armistice agreement, while 35 men were still being held in Communist captivity as of June 1954. The men who flew and supported the B-29s in the Far East Command were an important part of the air war over Korea, but their contribution has seldom been recognized.

B-29 (s/n 42-65281) Miss America 62. This aircraft is displayed outdoors at the Jimmy Doolittle Air & Space Museum on Travis AFB in Fairfield, CA.

B-29A (s/n 42-93967) City of Lansford. This aircraft is displayed outdoors at the Georgia Veterans State Park in Cordele, GA.

B-29 (s/n 44-27297) Bockscar. This aircraft is displayed indoors at the National Museum of the United States Air Force at Wright-Patterson AFB in Dayton, OH.

B-29 (s/n 44-27343) Tinker's Heritage. This aircraft is displayed outdoors at Tinker AFB in Oklahoma City, OK.

B-29A (s/n 44-61669) Flagship 500. This aircraft is displayed outdoors at March Field Air Museum at March ARB in Riverside, CA.

B-29A (s/n 44-61671) The Great Artiste. This aircraft is displayed outdoors at Whiteman AFB in Knob Noster, MO.

B-29 (s/n 44-61748) It's Hawg Wild. This aircraft is displayed indoors at the Imperial War Museum in Duxford, England.

B-29A (s/n 44-61975) Jack's Hack. This aircraft is displayed indoors at the New England Air Museum in Windsor Locks, CT.

B-29 (s/n 44-62022) Peachy. This aircraft is displayed indoors at the Pueblo Weisbrod Aircraft Museum in Pueblo, CO.

B-29 (s/n 44-62220) Joltin Josie. This aircraft is displayed outdoors at the USAF History & Traditions Museum on the grounds of Lackland AFB in San Antonio, TX.

B-29A (s/n 44-69729) T Square 54. This aircraft is displayed outdoors at the Seattle Museum of Flight in Seattle, WA.

B-29A (s/n 44-69972) Doc. This aircraft is stored indoors at the Kansas Air Guard Hangar across from the Kansas Aviation Museum in Wichita, KS. Not available to the public.

B-29A (s/n 44-70016) Sentimental Journey. This aircraft is displayed indoors at the Pima Air and Space Museum next to Davis-Monthan AFB in Tucson, AZ.

B-29 (s/n 44-70049). In storage for Kermit Weeks at Borrego Springs, CA. One of 4 B-29's obtained by Disney from China Lake for use in the movie The Last Flight of Noah's Ark..

B-29A (s/n 44-70064) Raz'n Hell. This aircraft is displayed outdoors at the Castle Air Museum at the former Castle AFB in Atwater, CA. It is actually a composite of three B-29s : 44-61535 - tail, 44-84084 - wings, 44-70064 fuselage.

B-29 (s/n 44-70113) Sweet Eloise. This aircraft is displayed outdoors at Dobbins ARB in Marietta, GA.

TB-29B (s/n 44-84053) Big Red. This aircraft is displayed indoors at the Museum of Aviation at Robins AFB in Warner Robins, GA.

TB-29B (s/n 44-84076) Man'O'War. This aircraft is displayed indoors at the Strategic Air and Space Museum next to Offutt AFB in Ashland, NE.

B-29 (s/n 44-86292) Enola Gay. This aircraft is displayed indoors at the National Air and Space Museum in Washington, DC.

B-29 (s/n 44-86408) Haggerty's Hag. This aircraft is displayed outdoors at the Hill Aerospace Museum at Hill AFB in Ogden, UT.

B-29A (s/n 44-87627) unnamed. This unnamed aircraft is displayed outdoors at the Eighth Air Force Museum at Barksdale AFB in Shreveport, LA.

KB-29M (s/n 44-87779) Legal Eagle II. This aircraft is displayed outdoors at the South Dakota Air and Space Museum next to Ellsworth AFB in Rapid City, SD.

B-29 (s/n 45-21739) Unification. This aircraft is displayed indoors at the KAI Aerospace Museum in Sachon, South Korea.

B-29 (s/n 45-21748) Duke Of Albuquerque. This aircraft is displayed outdoors at the National Atomic Museum next to Kirtland AFB in Albuquerque, NM.

P2B-1S (s/n 45-21787) Fertile Myrtle. Nose section only. On display at the Florida Air Museum in at Lakeland Linder Regional Airport in Lakeland, FL. The fuselage is in storage at Aero Trader in Borrego Springs, CA. This aircraft was used for the flight sequences in the Disney movie The Last Flight of Noah's Ark and the movie The Right Stuff.

Only five B-50 type aircraft survive today from the 370 produced:

B-50A (AF Ser. No. 46-0010) Lucky Lady II is disassembled and the fuselage is stored outside at Planes of Fame in Chino, California.

WB-50D (AF Ser. No. 49-0310) is on display at the National Museum of the United States Air Force at Wright-Patterson AFB in Dayton, Ohio.

WB-50D (AF Ser. No. 49-0351) is on display at Castle Air Museum at the former Castle AFB in Atwater, California.

KB-50J (AF Ser. No. 49-0372) is on display at Pima Air and Space Museum next to Davis-Monthan AFB in Tucson, Arizona.

KB-50J (AF Ser. No. 49-0389) is on display at MacDill AFB in Tampa, Florida. It is not accessible to the public.

B-29A (s/n 44-62070) Fifi. This aircraft is maintained and flown by the Commemorative Air Force B-29/B-24 Squadron.