Boeing B-29

Boeing B-29 Superfortress
USAAF Boeing B-29-40-BW "Superfortress"
Type:	Strategic bomber
Design country:	United States
Manufacturer:	Boeing Airplane Co.
First flight:	September 21, 1942
Commissioning:	May 8, 1944
Production time:	1943 to 1946
Number of pieces:	3970

Superfortress B-29-90-BW in flight

The Enola Gay on Tinian

B-29 bombing Korea

The Boeing B-29 Superfortress was a long-range bomber made by the American manufacturer Boeing Airplane Company in the 1940s. It was the largest and most powerful bomber of World War II and was still in service in the early stages of the Cold War . The maximum take-off weight could be more than double that of the previous Boeing B-17 “Flying Fortress” model . The letter "B" in the name stood for bombers. The B-29 is one of the most complex and cost-intensive armaments programs of the Second World War.

The Twentieth Air Force (20 AF) of the United States Army Air Forces (USAAF) first used the four-engine mid - decker in the summer of 1944. B-29 were also used for the atomic bombs dropped on Hiroshima and Nagasaki .

history

prehistory

Boeing's experience with the design and construction of large four-engine bombers goes back to the XB-15 (Model 294) of 1934. The subsequent concept of the Model 316 with a nose-wheel landing gear and four 2000 hp Wright R-3350 Duplex Cyclone radial engines was derived from this which at that time were still in the drawing board stage. The Model 322 from March 1938 was a further development with the structure of the B-17, which was combined with a newly developed pressure-ventilated fuselage. Four radial engines Pratt & Whitney R-2180 and a bomb load capacity of 4500 kg were planned. Although the development took place on behalf of the USAAC and was assessed positively, the Army did not place a production order due to a lack of financial means.

However, Boeing continued the development at its own expense and presented the Model 333A at the end of 1938 and the Model 333B in March 1939 , in which the pressurized cabin was for the first time divided into two sections, which were connected by a crawl tunnel above the bomb bay. In variant B, the engines, which are completely housed in the thick wing, are worth mentioning; however, this design was replaced by a conventional arrangement in the Model 334A from July 1939. With a crew of twelve men, the 334A should be able to carry a bomb load of 900 kg over a distance of 8000 km. In December 1939, Boeing built a partial dummy of this design.

A committee appointed by USAAC head General Henry 'Hap' Arnold and led by WG Kilner was tasked with determining the requirements for future fighter jets. It recommended the development of new medium and long-range bombers in June 1939. In December 1939 the technical requirements for a new bomber were announced in the data booklet XC-218. Accordingly, the range should be almost 8,600 km and the bomb load should be 900 kg. The speed of 643 km / h (400 mph) that could be achieved was also a challenge at the time. Boeing, Consolidated , Douglas and Lockheed , who submitted their respective concept proposals for assessment in February 1940, received the specifications.

Boeing's design work for the Model 341 had already begun parallel to the Model 334A in August 1939. The 341 was to have a high aspect ratio wing and a high lift profile , while four Pratt & Whitney R-2800s , each with 2000 hp, were provided. The top speed should be 652 km / h, while a bomb load of 1016 kg was required over the longest range. Up to 4500 kg were possible over a shorter distance.

development

As a result of a data query (R-40B) from aircraft manufacturers in January 1940 on the experiences made in the European theater of war, some improvements to the designs could be introduced. A stronger defensive armament, improved armor and self-sealing tanks were identified as particularly important . Boeing took these findings into account in the further developed draft Model 345 , which provided for four remote-controlled, power-operated defensive towers, each with two 12.7 mm machine guns and an additional pair of machine guns and one 20 mm M-2 type B automatic cannon in a rear stand. Boeing replaced the R-2800 radial engines with Wright R-3350 engines. The main landing gear was given double tires and now drove forward into the engine nacelles instead of sideways into the wings. The bomb carrying capacity was 1016 kg over 8580 km that of the 341 , but the maximum bomb load increased to 7300 kg. At 615 km / h (382 mph), however, the top speed did not quite reach the required value of 405 mph.

The factory submitted the draft of the Boeing 345 to the USAAC on May 11, 1940 and received a contract for further development including wind tunnel tests on June 17. Ten days later, all four manufacturers received preliminary engineering contracts, with the military designations being XB-29, Lockheed XB-30, Douglas XB-31 and Consolidated XB-32. Of these manufacturers, however, only Boeing and Consolidated continued work on the long-range bomber. The US Army considered the Model 345 to be the most promising design, while the XB-32 should be continued in the event of the failure of the XB-29.

On August 24, 1940, USAAC placed a $ 3.6 million contract to build two XB-29 prototypes ( USAAC serial numbers 41-002 and 41-003) and a static rupture cell . After viewing a dummy at the end of November 1940, the order was extended to include the construction of a third airworthy model (41-18335) on December 14th.

The "Battle of Kansas"

Before the first prototype even flew, orders for 1,600 copies were received ( The Three Billion Dollar Gamble ) and assembly plants and a large number of suppliers were prepared for the production of the new superbomber across the United States. Not only did huge new assembly halls have to be built, but a large number of workers also had to be hired and trained (→ Rosie the Riveter ). Production preparation and development had already cost three billion dollars. The Manhattan project, with its similarly high costs, was directly linked to the success of the B-29, as no other means of transport for the atomic bombs came into question. The B-32 bomber designed by Consolidated for the same tender was far more conservative and only a few were built.

In January 1944 the first 100 B-29s were completed, but only 16 were operational. Since the Air Force, under pressure from the government, pushed for the model to be introduced as quickly as possible, but a large number of deficiencies emerged in this most complex bomber to date, 1200 technicians and engineers from the cell and engine manufacturers in Wichita were brought together in a large-scale operation to fix these errors in the first series aircraft. General "Hap" Arnold was in charge. Work was carried out on the machines around the clock in an approximately 150,000 m² field in the open air until they could finally be delivered to the troops. Struts, rudder and parts of the glazing had to be replaced by reinforced ones and all engines had to be removed again and brought up to the latest technical standard R-3350-23A. Among other things, air ducts and exhaust valves were replaced. Still, the engines remained a problem. After almost six weeks, the "battle" was won and 175 operational machines were able to start their way to China. The first really operational B-29 was christened “Hap Spezial” after General “Hap” Arnold . Curiously, it was one of the four machines that fell into the hands of the Soviets and served as a model for the Tu-4 . At the same time, the 20th Air Force was founded, whose sole purpose was to use B-29 against Japan. General Arnold himself led this unit, which acted completely autonomously within the USAAF. At the same time, hundreds of thousands of workers in India and China created the first operational bases for the bombers under the most primitive conditions and by hand as part of " Operation Matterhorn ". The aircraft were equipped with additional tanks in the bomb bay and transported to India via the Atlantic, Egypt and Iran. The additional tanks were still necessary because the B-29 had to transport some of their own fuel to the advanced bases in China. One of the early B-29s was therefore given the name "Esso Express" as a nose art .

construction

The B-29 was one of the first large aircraft with a pressurized cabin . The front cockpit area, the middle area with the places for the gunner and the stern stand were pressurized. The front and middle sections were connected by a tunnel (diameter about 80 cm) with pressure bulkheads at both ends. You had to lie down on a sled and you could move past the two depressurized bomb bays to the front or rear of the machine. The crew could do without oxygen masks up to 30 minutes before entering the target area , after which they had to be put on again because of the possible pressure drop in the aircraft in the event of a hit and the cabin pressure was adjusted to the external air pressure again . The towers for defensive armament, remotely controlled by gunmen under viewing domes, were also technically advanced. A rifleman could control one or more towers or hand them over to other riflemen. In the non-pressurized rear part of the fuselage there was an auxiliary power unit, which the rear gunner was responsible for operating. This meant that the aircraft was in the starting phase independent of external energy supply. In order to achieve the high accuracy required by the USAAF, the top-secret Norden bomb targeting device built by the company "Norden Systems" was used. It was stabilized in all three axes, connected directly to the autopilot of the B-29 and thus - with good visibility - very accurate. Shortly before and until the bomb was dropped, control of the machine, as with the B-17, was handed over from the pilot to the bombardier. The bombardiers had to acknowledge receipt of the target device in writing before each use. The north aiming device was also used when the first atomic bomb was dropped in August 1945. In the further course, more and more B-29s were retrofitted with the British H2S radar for bombing. The atomic bombs were dropped on Nagasaki with this system because of poor visibility. A B-29 consisted of over a million individual parts (see also Rosie the Riveter ) and was extremely complex with its many innovations and the as yet untested engines. Over the entire production period, the highly stressed Wright R-3350 engines were affected by cooling problems that often led to engine fires: a magnesium alloy was used for the crankcase instead of the usual aluminum to save weight .

production

The final assembly of the B-29 was carried out in four factories. (Bell, Atlanta; Boeing, Renton; Boeing, Wichita; Martin, Omaha). Only the first three aircraft were built in Seattle. The USAAF took over a total of 3960 aircraft between 1942 and 1946. Boeing, Renton built the B-29A (1119 aircraft), the rest the B-29. In the production of Bell 311 B-29B (produced January to September 1945) were included. In later statistics, the USAF states that 2537 B-29, 1119 B-29A and 311 B-29B, a total of 3967 aircraft, were taken over between 1943 and 1946. With the three XB-29 from 1942, a total of 3970 B-29 were produced.

Approval of the B-29 by the USAF:

Manufacturer	version	1942	1943	1944	1945	1946	TOTAL
Boeing, Seattle	XB-29	3					3
Boeing, Wichita	YB-29		14th				14th
Boeing, Wichita	B-29		73	722	825		1620
Martin, Omaha	B-29		1	99	436		536
Bell, Atlanta	B-29		4th	201	152		357
Boeing, Renton	B-29A			139	918	62	1119
Bell, Atlanta	B-29B				311		311
TOTAL		3	92	1,161	2,642	62	3,960

The B-29 was used not only as a bomber, but also in other functions. Between July 1, 1949 and June 30, 1953, 93 KB-29, 83 KB-29M, 121 KB-29P, 1 KB-29T and 1 YKB-29J were converted into tankers. At least 36 SB-29s flew in the emergency function. Over 700 TB-29s were used as a training aircraft. The RB-29 (originally F-13) was a reconnaissance aircraft of which over 200 were produced. Of these, 88 were converted to weather planes in 1950/51.

On June 30, 1950, the USAF still had 2,598 B-29s: 1,791 B-29, 87 KB-29, 2 KB-29P, 163 RB-29, 16 SB-29 and 539 TB-29. Of these, only 668 aircraft were active: 433 B-29, 82 KB-29, 2 KB-29P, 134 RB-29, 7 SB-29 and 10 TB-29.

commitment

During the Second World War, the B-29 was used exclusively by the Twentieth Air Force , which had been set up specifically for this purpose. General Henry "Hap" Arnold took over the management of this air fleet.

Operation Matterhorn

The B-29 was only used in the Pacific theater of war for strategic bombing raids on the main islands of Japan and strategically important targets occupied by Japan during World War II . First, the B-29 were stationed on four hastily prepared bases in Kharagpur / India (in the Calcutta area ), from where they flew to advanced field airfields in China ( Chengdu province ). From there the USAAF flew its first attacks on western Japan in June 1944. The first missions from China (Chengdu to Tokyo about 3300 km) turned out to be unsatisfactory due to the difficult supply by air "over the hill " (Himalaya) and the poor maintenance options in China and the machines were able to move from the Xinjin , Guanghan , Qionglai and Pengshan also only reach the southern part of Japan. As early as 1943, the Eareckson Air Station was also created on the Aleutian island of Shemya, a base suitable for B-29s. The ineffective route from China brought little success to speak of, and the Aleutian base was only ever used by a single B-29.

The Mariana Islands

Tinian Island taken from the north in 1945. In the foreground North Field with four runways, in the background West Field with two more.

The whole of Japan, however, was at a distance of around 2500 km within the range of the American bombers if they were stationed on the northern Mariana Islands (Tinian to Tokyo around 2350 km). Much thus depended on the capture of the northern Marianas and their expansion into bomber bases as quickly as possible. As early as November 1944, the 20th US Air Force bombed all of Japan from the islands of Saipan , Tinian and shortly before the end of the war from Guam . The islands had only been conquered by the Americans a few months earlier; the Navy Construction Battalion " SeaBees " began building the bases specifically intended for the B-29 units during the fighting. Once again there was a superlative, because the North Field on Tinian, built especially for the B-29, was the largest airfield in the world until then. On the neighboring island of Saipan there was another airfield for B-29 as well as three smaller ones for B-24 and various fighter units. The first B-29 to reach Saipan was No. 42-24614 "Joltin 'Josie", which was lost on April 1, 1945 in a takeoff accident on Tinian.

In the beginning, the B-29 - similar to the Boeing B-17 and B-24 in Europe - flew precision attacks on industrial facilities from great heights during the day using high-explosive bombs. However, these were not very successful due to the mostly unfavorable weather conditions over Japan. In addition, the losses from engine failures on the long approach and departure routes were high. The capture of Iwo Jima (about halfway from Tinian to Tokyo) improved the situation after emergency landing facilities for damaged B-29s had been created there. During these missions, the previously unknown phenomenon of jet streams was discovered.

After General Curtis E. LeMay had taken command of the 21st bomber group of the 20th Air Force , he had all defensive armament expanded, except for the tail end, in order to reduce the load on the fire-endangered engines by reducing the weight and thus increasing the reliability of the bombers. At the same time, he changed the attack tactics: his B-29s were to fly night attacks from now on, in which the lack of defensive armament had hardly any negative effects. Since precision attacks were much more difficult at night than during the day, the B-29 then flew area bombing with AN-M69 incendiary bombs from a relatively low height on the predominantly wooden urban areas, in which hundreds of thousands of Japanese civilians were killed. A large part of the Japanese arms industry was destroyed within a short time. In the largest and most devastating air raid on Tokyo on March 10, 1945, in which 279 machines mainly threw incendiary bombs ( napalm and phosphorus bombs ), over 83,000 people died in one night - more than the atomic bombing attack on Hiroshima. The incendiary bombs caused a firestorm of unprecedented size. 14 machines had to make an emergency landing on the return flight on Iwo Jima. In total, B-29s dropped around 170,000 tons of bombs in 25,500 missions from the Mariana Islands in eight months and most of the Japanese war industry and almost all major cities had been destroyed.

Mines and "pumpkin bombs"

A 5 ton bomb

In addition to the direct bombing raids on Japan, the B-29 was used as a mine-layer to hinder Japanese shipping. The 313th. Bombardment Wing carried out these operations, known as Operation Starvation , and dropped around 12,000 sea parachute mines. About 600 Japanese ships ran into such mines.

Parachute sea mine

The 509th Composite Group was a unit specially set up for the use of the atomic bombs. The so-called Silverplate -B-29 were the conversions for the transport of nuclear weapons. 18 such conversions were made, 15 of them stationed in Tinian. The squadron flew its first missions with so-called "pumpkin bombs". These were 5300 kg bombs that looked like the plutonium bomb "Fat Man", but were filled with 2900 kg of normal explosives . The ballistic properties were identical to those of "Fat Man" and 49 of them were dropped on Japan. After the drop, the crews practiced the departure procedure that was later used for the atomic bombs . The Silverplate conversions also served as observation aircraft for the effects of the weapons. One of these machines (44-27353), called "The Great Artiste", was involved in both atomic bombing in this role. Another B-29 (44-61671, MSN 11148) is on display outside Whiteman Air Force Base , with the registration number and painting of this machine .

The atomic bombs

Tinian North Field. v. l. No. "Big Stink", "The Great Artiste" and "Enola Gay"

On August 6, 1945, the first atomic bomb " Little Boy " was dropped over the Japanese city of Hiroshima from a B-29 called " Enola Gay " . The commandant was Colonel Paul Tibbets . The commander of the escort aircraft " The Great Artiste " was Major Charles Sweeney and another escort aircraft was flown by Captain George W. Marquardt.

Three days later, the B-29 called “ Bockscar ” dropped the “ Fat Man ” atomic bomb on Nagasaki . This time the commanding officer was Major Charles Sweeney . Accompanying aircraft were his "The Great Artiste", flown by Captain Frederick C. Bock (the crews had previously swapped their machines). Another escort aircraft over Nagasaki was the "Enola Gay", flown by Captain George W. Marquardt.

On July 1, 1946, as part of Operation Crossroads, the B-29 "Dave's Dream" dropped an atomic bomb on 73 obsolete naval ships near the Bikini Atoll in the Pacific, including the German cruiser Prinz Eugen and the aircraft carrier USS Saratoga . Five warships sank in the atomic bomb test and nine others were badly damaged.

The B-29 in Europe

In 1950 the Americans handed over 88 B-29s to the British (for whom the machine was called “Boeing Washington”). These were intended to replace the outdated Avro-Lincoln bomber fleet and bridge the time until the V-bombers, the first British jet-powered long-range bombers, were put into service. With the exception of a few copies for telecommunications and electronic reconnaissance, all machines returned to the USA at the end of 1954.

Final in the Korean War

In the Korean War 1950–1953, the B-29 was last used in combat. B-29 dropped another 167,000 tons of bombs in around 21,300 missions (~ 37% of the total of 450,000 tons dropped) and once again left a completely destroyed country . During the Korean War, too, there were some special modifications to accommodate the guided VB-13 Tarzon bomb. However, the appearance of the MiG-15 meant that the B-29 now had no real chance in the sky. Nevertheless, the last regular B-29 was not retired until 1960 (see also section: "Losses, Korea").

losses

In action over Japan

A B-29 spins off after a direct flak hit. One wing was torn off.

The Japanese armed forces were unable to counter the attacks with the B-29: the development of heavy anti-aircraft defense systems to defend against high-flying bombers was started late. The fighters had been wiped out in the great porter battles of the Pacific War, but far worse was the loss of the skilled pilots. Although instructions existed that the Japanese pilots should carry parachutes, they often refused because it was considered dishonorable to survive the crash of their own machine. Instead, the pilots tried to get their hit machine into an enemy ship / plane / etc. control in order to still cause damage in death (cf. Bushidō ). While in all major air battles over Europe and Africa the downed pilots of the warring powers were put back into service in large numbers, the Japanese air forces lost almost all of their experienced pilots in a few years. The few fighters could not be effectively introduced to the B-29 units due to the most serious deficiencies in the Japanese radar system. Due to the total air dominance of the Allies combined with an extreme lack of fuel, the tedious training of new pilots was no longer possible. The existing 70 mm and 80 mm guns were too weak compared to the initially very high flying B-29s (height and effective radius of the projectile explosion). Since the hit rate of the drops fell during bombing operations at high altitudes, attacks from medium and low altitudes were switched to, which also increased the losses by the flak and fighters. The 120 mm anti-aircraft guns introduced towards the end of the war came into use too late and in too few numbers. The elderly Japanese standard fighters Nakajima Ki-43 and Mitsubishi A6M "Zero " had a difficult time because they did not perform well at high altitude and their armament was too weak. In addition, the Japanese fighters were not armored and neither had self-sealing fuel tanks like the American aircraft. Thus, they were easy to shoot down by the B-29 gunner. The defensive armament could therefore - in contrast to the B-17F and G over Europe - even be reduced. Japanese fighter pilots achieved better success with the types Nakajima Ki-44 , Kawasaki Ki-61 and especially with the Nakajima Ki-84 . With the latter type, the Japanese ace fighter pilot Makoto Ogawa managed to shoot down seven B-29s. Only the Kawanishi N1K 1-J, N1K2-J, Mitsubishi J2M3 and from May 1944 the 12,000 m high Mitsubishi A7M2 "Reppu" would have been a serious danger if they had come earlier. Because the production facilities had already been largely destroyed, only eight “Reppu” were used by the end of the war. Overall, only 74 B-29s were lost to enemy action over Japan (54 to flak and 19 to flak and fighters). Based on the loss (through shooting down or total damage) of more than 18,000 US aircraft - of which 9,949 bombers - and 79,265 fallen crew members over Europe, the losses of the B-29 were relatively small.

Some B-29s had to make an emergency landing in the Soviet Union during 1944 . The Soviet Union kept the machines and Stalin gave OKB Tupolev the order to copy the B-29. The result was the Tupolev Tu-4 .

In World War II

Tinian Bomber Cemetery 1946

Of the 3763 aircraft taken over during the war, a total of 772 B-29s were lost by August 1945. 260 total write-offs occurred in the USA, the remainder (512) overseas. The 20th Air Force lost 502 aircraft, the remaining 10 aircraft were lost during the transfer. The operational losses amounted to 414 aircraft, of which 147 were due to enemy action (74 due to enemy aircraft, 54 due to anti-aircraft guns, 19 due to both reasons).

In use over Korea

In their last deployment in the Korean War , the situation turned decisively. It showed the superiority of the new jet-powered fighters over bombers with piston engines. There she suffered heavy losses from MiG-15 fighters due to her inadequate defensive armament . During operations from Japan, large parts of the defensive armament were removed for weight reasons. But after eleven B-29A were shot down or irreparably damaged within a week (October 22-27, 1951) despite escort protection by this Soviet type, the B-29 was withdrawn from use as a strategic day bomber and only at night or against tactical targets used outside the range of the MiGs. The first loss of a B-29 in this war occurred on July 12, 1950 and was caused by a Yak-9 . The US Air Force leadership was clearly demonstrated that their previous best weapon was obsolete in no time. These heavy losses had a major impact on all subsequent bomber developments.

In total, the USAF lost 82 aircraft in Korea (72 B-29, ten RB / WB-29), seven of which were not assigned to any unit. Of these, 60 were lost in combat (57 B-29, three RB / WB-29). Only the bombers lost aircraft to enemy action (a total of 24, of which 17 to enemy aircraft, five to anti-aircraft guns and two to both). Eight aircraft remained missing in action (six B-29, two RB / WB-29). In 20,448 deployments of the B-29 with the dropping of 168,368 short-tons bombs and 2535 deployments of the RB / WB-29, the loss rate was 0.3% and 0.2%, respectively. Personnel losses: 285 crew members were killed, 343 were missing and 96 were wounded. On a monthly average, the USAF owned 109 B-29 and 36 RB / WB-29 in Korea.

Total losses of the B-29 and its modifications

There are not all types of losses for all periods.

Losses of the B-29 / F-13 / RB-29 / TB-29 / SB-29 / KB-29:

year	losses	in action	of it by enemy	other losses	including aviation accidents
1943	3	0	0	3	3
1944	203	95	29	108	92
1945	584	319	118	265	196
1946					12
1947					21st
1948					23
01/01/1949 - 06/30/1949					12
07/01/1949 - 06/30/1950	38	0	0	38	33
07/01/1950 - 06/30/1951	48	22nd	9	26th	21st
07/01/1951 - 06/30/1952	63	25th	9	38	32
07/01/1952 - 06/30/1953	44	14th	6th	30th	27
07/01/1953 - 06/30/1954	12	1	0	11	10
07/01/1954 - 06/30/1955	4th	0	0	4th	3
07/01/1955 - 06/30/1956	8th	0	0	8th	7th
07/01/1956 - 06/30/1957	7th	0	0	7th	7th
07/01/1957 - 06/30/1958	2	0	0	2	1
07/01/1958 - 06/30/1959	1	0	0	1	1
TOTAL		476	171		501

KB-29 tanker

Production and stocks of the KB-29

(FY = Fiscal Year. The 1950 fiscal year ran from July 1, 1949 to June 30, 1950. Other departures include accidents and aircraft retirement)

plane	B-29M	KB-29	KB-29M	KB-29P	KB-29B	YKB-29J	YKB-29T
As of June 30, 1949	37
FY 1950 delivery to remodeling	37	1
FY 1950 access from renovation		93		2
FY 1950 other departures		5
As of June 30, 1950		87		2
FY 1951 submitted to renovation		62		1
FY 1951 addition from renovation			61	113		1
FY 1951 other departures		3		2
As of June 30, 1951		22nd	61	112		1
FY 1952 submitted to renovation		22nd		1	1
FY 1952 addition from renovation			22nd	4th	1
FY 1952 other departures			1	3
As of June 30, 1952			82	112		1
FY 1953 addition from renovation				2
FY 1953 other departures			1	5		1
As of June 30, 1953			81	109
FY 1954 other departures			3	2
As of June 30, 1954			78	107
FY 1955 addition from renovation							1
FY 1955 other departures			45	1
As of June 30, 1955			33	106			1
FY 1956 other departures			24				1
As of June 30, 1956			9	106
FY 1957 other departures			9	52
As of June 30, 1957				54
FY 1958 other departures				38
As of June 30, 1958				16
FY 1959 other departures				14th
As of June 30, 1959				2
FY 1960 other departures				1
As of June 30, 1960				1
FY 1961 other departures				1

The table above, which was created from information from the USAF's “Statistical Digests”, shows that the information in the literature on KB-29 is inaccurate.

The first tanker aircraft were given the designation B-29M, only to be renamed KB-29 in FY 1950. The existing KB-29s have most likely been converted to KB-29M, as shown by the process that spanned FY 1951 and 1952. The KB-29P was a conversion directly from the B-29 bomber.

Since there were three different refueling systems and three tank designations, these can be combined with one another:

• B-29M / KB-29: British "Hose System"
• KB-29M: "Probe-and-Drogue-System"
• KB-29P: "Flying Boom System"

The following production figures can be determined: 93 B-29M / KB-29, 83 KB-29M, 121 KB-29P. The YKB-29J was converted from a B-29A, the YKB-29T was converted from a B-29. The KB-29B is probably a conversion from a B-29B that was modified to the KB-29M in the same year. Unless a tanker was lost before June 30, 1949, 217 bombers were converted to tankers (without taking the KB-29M into account).

Further developments

Almost simultaneously with the USAAF's B-29 tender in 1941, a machine with an even greater range was required: in the event that Great Britain was lost in the European part of World War II, a “superbomber” with a USA-Europe-USA range was necessary . The huge six-engine (later ten-engine) Convair B-36 "Peacemaker" was born from this requirement . Boeing wanted to save the service life and the commercial success of the B-29 and perfected the air refueling with a fixed boom ("Flying Boom") that is still common today. As a result, the B-29 could also have met this requirement.

Derivatives

From this demand for extreme range, the Boeing B-50 emerged as a military development of the B-29.

After the Second World War, the Boeing C-97 "Stratofreighter" was used to develop a cargo aircraft from the extremely complex high-performance wings, the tail unit and the landing gear . The hull was a new design. This was largely funded by the USAF and a civil version was developed from it - the Boeing 377 "Stratocruiser". The engines were more powerful and reliable, otherwise the main data were almost identical. Then emerged for from decommissioned "Strato Cruiser" NASA , the Guppy , Pregnant Guppy and Super Guppy Transport extremely bulky goods such as rocket components and the like. Airbus used Super Guppies to transport aircraft components between the individual plants in Europe until Beluga took over this task from its own production in 1994 .

After four B-29s fell into the hands of the Soviets after emergency landings, Tupolev produced a more or less exact copy, which - albeit with different engines - went into series production as the Tu-4 . The exact number varies between 850 and 1200 copies . From the Tu-4, in turn, the passenger variants Tu- / 0/75 and the enlarged Tu-80/85 bombers emerged. Various constructive details of the B-29 can still be seen in the Tu-95 of our day. Like the B-29 in the west, the Tu-4 was also subjected to many modifications, including as an AWACS aircraft. The enormous adaptability of the basic design was evident in both the West and the East. China also received a small number of Tu-4s, which in turn were modified with turboprop engines, for example. It can be assumed that no other model has influenced modern large aircraft construction as much as the B-29.

Cold War incidents

On April 11, 1950, three minutes after taking off from Kirtland Air Force Base with an atomic bomb on board , a B-29 crashed onto a mountain near the Manzano Nuclear Weapons Storage Area (WSA) in Albuquerque , New Mexico, in its underground storage facilities Nuclear weapons were in stock. 13 crew members were killed. The explosive charge of the bomb caught fire, but there was no nuclear explosion. The fire could still be seen at a distance of 15 miles.

On December 26, 1950, an RB-29 entered Soviet airspace over the Baltic Sea and was shot down by two MiG-15s off Primorye . The crew was not found.

On June 13, 1952 also two MiG-15 shot a RB-29 reconnaissance aircraft (Air Force no.  44-61810 ) of the 91st Strategic Reconnaissance Squadron from which on a PHOTINT Mission (Photographic Intelligence) over the Sea of Japan was . The twelve crew members are still missing today.

Also during a PHOTINT mission, the RB-29 No.  44-61815 of the 91st SRS was intercepted and shot down by two Soviet La-11 fighters north of the Japanese island of Hokkaidō on October 7, 1952 after the crew ignored the request to land . The eight-man crew is missing, only one member was recovered dead by the Soviet side and buried on the Kuril island of Juri. In 1994 the remains were transferred to the USA.

On January 13, 1953, an American B-29 for special operations called "Stardust 40" had to land in the People's Republic of China. The crew members interned as prisoners of war were only released in August 1955.

Supersonic and parasite hunters

The XF-85 hung under an EB-29

Since the B-29 was the only suitable aircraft to carry the Bell X-1 and Bell X-2 research aircraft , some machines were converted as carrier aircraft. On October 14, 1947, a B-29 carried the X-1 "Glamorous Glennis" with Captain Charles "Chuck" Yeager at starting altitude for the first supersonic flight . For the Convair B-36, considerations were in progress to equip them with their own on-board fighter , similar to the earlier airships of the US Navy "Akron" and "Macon" . The tests with the McDonnell XF-85 were also carried out with a modified B-29.

Technical specifications

Boeing B-29 "Superfortress"

Parameter	Data
crew	10-14
length	30.18 m
span	43.05 m
height	9.02 m
Empty mass	33,800 kg (approx. 30,500 kg with the rotating towers removed)
Max. Takeoff mass	62,560 kg
drive	four double radial engines Wright R-3350-23 Duplex Cyclone with 2230 HP (1640 kW) each
Top speed	576 km / h at 9150 m altitude
Summit height	10,250 m
normal range	5000-5200 km
Transfer range	6800-7000 km
Armament	twelve 12.7 mm machine guns ( Browning M2 , caliber .50 BMG ) in remote-controlled weapon stands, one 20 mm machine cannon ( M1 ) in the rear, 9,072 kg  bombs

Fuel and range

The B-29 had five self-sealing main tanks integrated into the wings, which could hold around 26,200 l (19 t) of fuel. If required, up to four additional containers could be installed in the bomb bays, each holding 2400 l (1.7 t). During the Silverplate conversions, two of these additional tanks were permanently installed in the rear bomb bay. The distance from Mather AAF in Sacramento / California to Hickham AAF / Hawai was around 4000 km, and that from Hickham to Tinian and Saipan around 6000 km. Thus, the machines could be transferred to their bases on the Mariana Islands with just one stopover. The only emergency landing options on the entire route were makeshift airfields on the Marshall Islands , on the Enewetak Auxiliary Airfield and on the island of Kwajalein . Of course, the range was linked to the altitude and payload. During a flight at a very high altitude with 2300 kg bombs, the radius of action was 2600 km. At medium heights, 5400 kg could be carried with the same radius of action. At low altitudes, the same route could be flown with a full bomb load. In an attack on the oil refinery in Palembang (Sumatra) on August 10, 1944, the B-29s covered a total of 6200 km, laden with only one tonne of bombs on board. The longest duration of an assignment was 19 hours.

Typical payloads

Typical payloads were: (GP = US standard high-explosive bombs)

• 56 × AN-M57GP (113 kg) = 6.35 t
• 40 × AN-M64GP (227 kg) = 9.04 t
• 12 × AN-M65GP (454 kg) = 5.44 t
• 8 × AN-M66 (907 kg) = 7.26 t
• 4 × AN-M56 (1814 kg) = 7.26 t
• 12 × AN-Mk26 sea mines = 5.44 t
• 8 × AN-Mk24 sea mines = 7.26 t
• 40 × AN-M76 incendiary bombs = 8.6 t
• 40 × M19 (E-46) cluster bombs with 38 AN-M69 Napalm bombs each (1520 pieces), ~ 7.6 t
• 56 × M18 (E-28) cluster bombs each with 38 AN-M69 napalm bombs (2128 pieces), ~ 8.9 t
• 38 × M31 (E-48) cluster bombs each with 38 AN-M74 Napalm bombs (1444 pieces), ~ 9.04 t
• 184 × AN-M47 incendiary bombs, ~ 5.8–8.3 t depending on the filling

Received aircraft

44-62070 "Fifi"

"Fifi" on landing in Oshkosh

The Commemorative Air Force operates one of two globally airworthy B-29s; a B-29A with serial number 44-62070 called "Fifi".

44-69972 "Doc"

"Doc" in July 2016

Since 1999 a second B-29 “Doc” (44-69972) has been restored to airworthy condition by a group of aviation enthusiasts. It completed its rollout in March 2015 and was originally supposed to complete its first flight in the same year. The first start in 60 years was successful on July 17, 2016.

45-21768

In Greenland , a B-29 called “Kee Bird”, which had not landed in 1947 due to a lack of fuel, stood in a largely intact condition on a remote ice surface for a long time. In an attempt to restore the aircraft and get it fit again, it caught fire while taxiing in May 1995 and was largely destroyed. The cause was the only provisionally attached tank of the power generator in the rear of the fuselage, now known as the “auxiliary power unit” in modern commercial aircraft, which had come loose due to the vibrations during take-off. This created a leak in the fuel supply line. All deletion attempts were unsuccessful. The (now submerged) wreck is still in the same place today.

More copies

There are also 24 other B-29s in museums, 22 of them in the USA, one in South Korea and the only one exhibited in Europe in Duxford / Great Britain.

See also

• List of aircraft types

Web links

Commons : B-29 Superfortress  - Album with pictures, videos and audio files

• B-29. Superfortress. In: History - Products. Boeing, accessed January 10, 2015 (manufacturer's website). 
• photos
• American propaganda film about the construction of the B-29
• Sighting of a B-29 wreck in Greenland

literature

• David Willis: Boeing B-29 and B-50 Superfortress - Warplane Classic. In: International Air Power Review. Volume 22, 2007, pp. 136-169.
• Robert F. Dorr: Boeing B-29 Superfortress - Database. In: Airplane Monthly. September 2005, pp. 57-72
• Lindsay Peacock: Boeing B-29 ... first of the superbombers Part 1 - Warbirds. In: AIR International. August 1989, pp. 68-76, 87.
• Lindsay Peacock: Boeing B-29 ... first of the superbombers Part 2 - Warbirds. In: AIR International. September 1989, pp. 141-144, 150 f.

Individual evidence

1. ↑ Statistical Digest of the USAF 1956. p. 147. In Wichita either 1634 or 1644 B-29 were produced.
2. ↑ Statistical Digest of the USAF 1946. P. 94 ff.
3. ^ Statistical Digest of the USAF 1949-1952. various tables
4. ↑ Statistical Digest of the USAF 1949. pp. 179 ff.
5. ^ Kit C. Carter and Robert Mueller: Combat Chronology. (PDF) US Army Air Forces in World War II. In: Air Force Historical Support Division. United States Air Force, 1991, pp. 642–643 , accessed on October 11, 2016 (English): “During the predawn hours 279 B-29's, of 325 airborne, blast Tokyo urban area with incendiaries, destroying more than 267,000 buildings about one-fourth in the city and killing more than 83,000 people. " 
6. ↑ Joe Baugher: 1944 USAAF Serial Numbers (44-001 to 44-30910).
7. ↑ Joe Baugher: 1944 USAAF Serial Numbers (44-40049 to 44-70254).
8. ↑ ^{a b c d e} Iain Parsons: The great book of dogfights. 1974 and 1985, Salamander Books, pp. 140-141.
9. ↑ Hans Wehrle: The Second World War. Federal Ministry of Defense, Bonn 1986, p. 317.
10. ↑ Steven Joseph Zaloga: Defense of Japan 1945. 2010, pp. 54–55.
11. ↑ Erich Hampe: The civil air defense in the Second World War - The course of the air war. (PDF; 18 MB, pp. 95, 136) 1968, accessed on September 2, 2019 . 
12. ↑ Statistical Digest of the USAF 1945. P. 148, P. 261.
13. ↑ Diego F.Zampini: Red aces over North Korea. Part 1. Flieger Revue Extra No. 22, Möller, Berlin 2008, p. 14. Lt. Statistical Digest of the USAF 1953, p. 57 ff., In which the losses of the Korean War were summarized in detail, only nine aircraft were lost in October 1951, seven of them in service. Four were shot down by enemy aircraft and one by flak. Two more losses occurred without enemy interference.
14. ↑ Statistical Digest of the USAF 1953. pp. 28 ff.
15. ↑ Statistical Digest of the USAF 1945-1960. USAF Aircraft Gains and Losses table; USAF Aircraft Losses by Cause table; https://www.aviationarchaeology.com/src/db.asp
16. ↑ Statistical Digest of the USAF 1950–1962. USAF Aircraft Gains and Losses table; Table "Status and Line Classification of USAF Aircraft by Type and Model"; USAF Aircraft Functional Distribution by Type, Model, and Selected Series table
17. ↑ ^{a b c} Archive link ( Memento from August 17, 2013 in the Internet Archive ) Gregory W. Pedlow , Donald E. Welzenbach: The Central Intelligence Agency and Overhead Reconnaissance: The U-2 and OXCART Programs, 1954–1974. 1992, Chapter 1: Early Postwar Aerial Reconnaissance. PDF, p. 16.
18. ↑ DPMO Cold War Incidents Report: Incident Data 2000-08-31 ( Memento of February 14, 2010 in the Internet Archive )
19. ^ Joachim Bashin, Ulrich Stulle: Hot Heaven in the Cold War. In: Flieger Revue Extra No. 4, p. 46.
20. ↑ CAF B-29 / B-24 Squadron. Home of the Worlds only B-29 Superfortress. (No longer available online.) Commemorative Air Force, archived from the original on Jan. 11, 2015 ; accessed on August 18, 2019 . 
21. ↑ Doc's Friends Hold Rollout for B-29 Known as “Doc”. (No longer available online.) In: News. Doc's Friends, March 15, 2015, archived from the original on October 11, 2016 ; accessed on October 11, 2016 (English): "On track to fly later this year, Doc will be one of only two restored B-29s in flying condition." Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.  
22. ↑ Rachel Waller: B-29 'Doc' takes to the skies from McConnell. In: McConnell Air Force Base. United States Air Force, July 17, 2016, archived from the original on November 16, 2016 ; accessed on September 11, 2018 (English). 
23. ↑ Alexis von Croy: Adventurer of the Skies. ISBN 3-492-24335-5 , pp. 273-294.
24. ^ Thule Air Base. Accessed April 11, 2019 (German). 
25. ↑ WORLD: Satellite image: B-29 bombers from Cold War discovered in ice . June 8, 2014 ( welt.de [accessed April 11, 2019]).