Boeing B-29 Superfortress

Updated: October 2026 – A deep, steady drone from four big radial engines, and above it a silver fuselage with a glass nose like a soap bubble: when that passes over an airshow field, it is very likely a Boeing B-29 Superfortress. The bomber was a huge technical leap, politically one of the most consequential aircraft of the 20th century, and for spotters today a real rarity. Here you will learn how the B-29 came about, how to recognize it, what is behind the Enola Gay and Bockscar, where the two airworthy aircraft, FIFI and Doc, are active, and why the Soviet Union rebuilt the type screw by screw.

What is the Boeing B-29 Superfortress?

The B-29 is a four-engine heavy long-range bomber that Boeing developed for the US Army Air Forces starting in 1940. The requirements were extreme for the time: carry a large bomb load over thousands of kilometers, fly faster and higher than the B-17 Flying Fortress, and keep the crew reasonably comfortable for many hours.

The result was an aircraft with a very slender, long wing of a good 43 meters in span, a round fuselage about 30 meters long and four Wright R-3350 Duplex Cyclone radial engines with two turbochargers each. The XB-29 prototype took off from Boeing Field in Seattle on September 21, 1942. The type entered combat service in 1944, and by 1946 3,970 aircraft had been built. No other American weapons project of World War II consumed more money – development and production cost around three billion US dollars by common estimates.

Pressurized cabin and remote-controlled turrets: what was new on the B-29

Two technical innovations make the B-29 remarkable to this day.

The pressurized cabin. The B-29 was the Allies’ first production bomber in which the crew did not sit in freezing, thin air. Garrett AiResearch supplied the pressurization system. The nose compartment with pilots, bombardier, navigator and radio operator, the middle section with the gunners and the tail gunner station were pressurized. The bomb bays in between could not be sealed, so a narrow, padded tunnel above the bays connected the forward and rear areas. If you crawl through a museum fuselage, you quickly understand how tight it was.

Remote control of the guns. Instead of manned ball turrets, the B-29 had four flat turrets on top of and beneath the fuselage with heavy machine guns. The gunners sat at sighting stations in the nose, in the tail and in the side blisters and operated the turrets through a central General Electric fire-control system. Analog computers took airspeed, lead and other factors into account, and one gunner could take over several turrets. The tail position was also manned; early aircraft carried a 20 mm cannon there in addition to the machine guns.

The downside was complexity. The R-3350 engines in particular tended to overheat and catch fire at first. On February 18, 1943, the second prototype crashed in Seattle after an engine fire; chief test pilot Edmund T. “Eddie” Allen, his crew and people on the ground were killed. The program went on regardless, under enormous time pressure.

Versions and derivatives

The B-29 was built at four plants: at Boeing in Wichita and Renton, at Bell in Marietta, Georgia, and at Martin in Bellevue near Omaha, Nebraska. Externally, the production series differ only in details.

Version	Origin	Special feature
B-29	Wichita, Bell, Martin	Base version with four remote-controlled turrets
B-29A	Renton	Modified wing structure, wingspan about 30 cm larger
B-29B	Bell Marietta	311 built, most without turrets except the tail position, but lighter
F-13 / RB-29	Conversions	Photo reconnaissance aircraft
KB-29	Conversions from 1948	Tanker aircraft
WB-29 / SB-29	Conversions	Weather reconnaissance and rescue aircraft respectively
Washington B.1	Loan to the RAF	87 aircraft, in service from 1950 to 1954

The “Silverplate” aircraft were a small series modified for dropping atomic bombs – these included the Enola Gay and Bockscar. After the war, the B-29D became the B-50 with more powerful Pratt & Whitney R-4360 engines and a taller tail.

Boeing’s postwar transports and airliners also descend from the B-29: the C-97/KC-97 Stratofreighter and the civilian Boeing 377 Stratocruiser took over the wing, tail and landing gear concept and put a second, thicker fuselage section on top. The jet-age Boeing bombers that followed were the B-47 Stratojet and the B-52 Stratofortress, still active today.

Enola Gay and Bockscar

The most famous B-29 is an aircraft from the Martin plant in Nebraska with the serial number 44-86292: the Enola Gay. Colonel Paul W. Tibbets Jr. named it after his mother. On August 6, 1945, he took off in it from North Field on the Pacific island of Tinian and at 8:15 a.m. local time dropped the atomic bomb “Little Boy” on Hiroshima. Three days later, on August 9, the B-29 Bockscar followed under Major Charles W. Sweeney with the bomb “Fat Man,” which hit Nagasaki. Tens of thousands of people died instantly, many more from the aftereffects. A few days later, Japan surrendered.

Both aircraft are museum pieces today – and places where you fall silent:

• The Enola Gay is on display, restored, at the Smithsonian’s Steven F. Udvar-Hazy Center near Washington Dulles, where it has been since the opening in December 2003. The center is right at the airport; you will find more about visiting under Udvar-Hazy Center at Washington Dulles Airport.
• Bockscar (44-27297) is shown by the National Museum of the US Air Force in Dayton, Ohio. Visiting tips are at Museum and airfield Dayton.

The two aircraft are historical testimony, not showpieces of heroism. The museums assess their role differently; at the Smithsonian in particular, the presentation of the Enola Gay was long the subject of public debate. Take your time with the accompanying information when you visit.

After 1945: Korea, tankers and the end

The B-29 was not retired when the war ended. In the Korean War from 1950 it flew about 20,000 sorties. Against the fast MiG-15 fighters, however, it was too vulnerable by day; after painful losses, the US Air Force moved the attacks mostly to night. A reconnaissance squadron flew the last B-29 mission of the war on July 27, 1953, the day of the armistice.

After that, the type lived on in secondary roles: as the KB-29 tanker, as the WB-29 weather reconnaissance aircraft, as a target tug and test platform. In June 1960, service with the US Air Force ended. Many retired airframes ended up as targets on firing ranges – among others at the Navy station China Lake in the California desert. That is exactly where the story of the last two airworthy Superfortresses begins.

FIFI and Doc: the last flying B-29s

Seeing a B-29 in the air is only possible in North America today – and only with these two aircraft.

FIFI is a B-29A built in Renton with the serial number 44-62070. It served as an administrative aircraft, spent some time in the desert storage yard and, after being retired in 1958, went to China Lake. In 1971 a pilot of what was then the Confederate (now Commemorative) Air Force discovered it, and the organization took over the aircraft and made it airworthy again. After engine problems, FIFI stayed on the ground from 2006. For its return it received new hybrid engines, assembled from parts of later R-3350 variants, and flew again on August 5, 2010. Its home today is a hangar at Dallas Executive Airport in Texas, and the registration is N529B. The Commemorative Air Force is a nonprofit organization that keeps historic military aircraft airworthy.

Doc is a B-29 built in Wichita with the serial number 44-69972. It never saw combat, flew as a radar calibration aircraft and target tug, and in 1956 also ended up as a target at China Lake. From 1987, Air Force veteran Tony Mazzolini drove the rescue effort; after the transfer in 1998, the wreck was dismantled and brought to Wichita. Volunteers restored the aircraft over many years; in 2013 the nonprofit Doc’s Friends took it over. On July 17, 2016, Doc took off in Wichita for its first flight in about 60 years; the registration is N69972.

	FIFI	Doc
Version	B-29A	B-29
Built at	Boeing Renton	Boeing Wichita
Serial number	44-62070	44-69972
Registration	N529B	N69972
Operator	Commemorative Air Force	Doc’s Friends
Back in the air	1971, again in 2010 after a break	2016
Home	Dallas, Texas	Wichita, Kansas

Both aircraft tour the USA during the season, partly offer rides and are regularly seen at major events such as EAA AirVenture in Oshkosh. A meeting of both Superfortresses in the air is rare and an event every time.

The copy from Moscow: Tupolev Tu-4

In 1944, after missions against Japan, four B-29s had to make forced landings in the Soviet Far East or were abandoned; one of them crashed after its crew bailed out. The Soviet Union was still neutral toward Japan at the time, interned the crews and kept the three intact aircraft. Stalin had the Tupolev design bureau derive its own bomber from them – not design a new one, but rebuild it.

The result was the Tu-4. It first flew on May 19, 1947, and appeared before the public at the air parade in Tushino on August 3, 1947. Western observers were stunned at how exactly the copy matched the original. It was powered by Soviet Shvetsov ASh-73TK radial engines, and armament and equipment came from domestic production. By 1952, 847 aircraft had been built.

The significance of the Tu-4 goes far beyond being a clone:

• It gave the Soviet Union its first bomber with strategic range; the Tu-4A version was the first Soviet aircraft to drop an atomic bomb.
• Its technology – pressurized cabin, fire control, production methods – flowed into later Tupolev developments. Prototypes such as the Tu-70 airliner and the Tu-80 and Tu-85 bombers built directly on it.
• The line continues to the Tu-95 “Bear”, which still flies today.
• China received Tu-4s from 1953; the last one left service there only in 1988, and some were converted to turboprops in the 1970s.

You can see a Tu-4 at the Central Air Force Museum in Monino near Moscow, and more are on display in China.

How to recognize a B-29

The Superfortress is surprisingly distinctive for a four-engine warbird if you check three things.

Feature	B-17	B-29	B-50	Avro Lancaster
Engines	4 radials	4 radials	4 radials (R-4360)	4 inline engines
Landing gear	Tailwheel	Nose wheel	Nose wheel	Tailwheel
Nose	Glass nose plus cockpit step	All-glass, no step	All-glass, no step	Glass nose plus canopy
Tail	Single, large	Single, tall	Single, much taller	Twin
Fuselage	Rather narrow	Round, long	Round, long	Angular

The British counterpart is covered on the Avro Lancaster page, and twin-engine warbird bombers like the B-25 Mitchell have a page of their own. General tips for vintage aircraft are in How to recognize historic aircraft.

Where to see a B-29 on the ground

Around two dozen B-29s are preserved, almost all in the USA. A selection worth a spotter trip:

Place	Aircraft	Note
Imperial War Museum Duxford, England	B-29A “It’s Hawg Wild” (44-61748)	only B-29 on display in Europe, in the American Air Museum
Udvar-Hazy Center, Chantilly	Enola Gay (44-86292)	Hiroshima aircraft, in the large main hangar
National Museum of the US Air Force, Dayton	Bockscar (44-27297)	Nagasaki aircraft; plus a walk-through fuselage
Museum of Flight, Seattle	“T Square 54” (44-69729)	at Boeing Field, where the XB-29 first flew
Pima Air & Space Museum, Tucson	“Sentimental Journey” (44-70016)	part of one of the largest aircraft collections in the world

For Europeans, Duxford is the obvious address: the B-29 stands there in the American Air Museum among many other US military aircraft. The airfield and its airshows are covered on the pages IWM Duxford as a spot and Duxford airshows. In Seattle you can combine the B-29 with the active flight operations at the Museum of Flight at Boeing Field, and in Tucson with the huge Pima Air & Space Museum.

Displays change because of restorations or hangar renovations. Before you visit, check whether the aircraft is currently accessible.

Tips for photos and visits

• Indoors: With a 43-meter wingspan, a B-29 barely fits in the frame. A wide-angle lens and some distance help; find an elevated vantage point if possible. Plan detail shots of the glass nose, turrets, sighting blisters and serial number.
• At airshows: For spinning propellers you need longer shutter speeds and clean panning shots. Photographing propellers shows how it works. Photographing airshows explains choosing your position and gear.
• At engine start: The start-up of the big radial engines with smoke and backfires is a subject of its own. Stay near the parking area for it.
• Document it: Note the serial number and registration and post the sighting with photo and location. That way your warbird collection grows in a traceable way.

If you would like to pitch in yourself: many preserved bombers exist only thanks to volunteers. How you can take part in such projects is in the article Volunteering at aviation museums.

Conclusion

The B-29 Superfortress stands for a technical leap – pressurized cabin, remote-controlled turrets, enormous range – and at the same time for the darkest chapter of air war history. It gave rise to American bombers, tankers and airliners, and in the Soviet Union, through the Tu-4, to the beginning of a long-range bomber line of its own. Today you mostly meet it in a museum, with Duxford as the only address in Europe. Only FIFI and Doc still get them into the air.