Tupolev TB-3
Encyclopedia
The Tupolev TB-3 was a heavy bomber aircraft which was deployed by the Soviet Air Force
Soviet Air Force
The Soviet Air Force, officially known in Russian as Военно-воздушные силы or Voenno-Vozdushnye Sily and often abbreviated VVS was the official designation of one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces...

 in the 1930s and during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. It was the world's first cantilever wing four-engine heavy bomber. Despite obsolescence and being officially withdrawn from service in 1939, TB-3 performed bomber and transport duties through much of World War II. The TB-3 also saw combat as a Zveno project
Zveno project
Zveno was a parasite aircraft concept developed in the Soviet Union during the 1930s. It consisted of a Tupolev TB-1 or a Tupolev TB-3 heavy bomber acting as a mothership for between two and five fighters...

 fighter mothership and as a light tank transport.

Development

In 1925, the Soviet Air Force
Soviet Air Force
The Soviet Air Force, officially known in Russian as Военно-воздушные силы or Voenno-Vozdushnye Sily and often abbreviated VVS was the official designation of one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces...

 approached TsAGI
TsAGI
TsAGI is a transliteration of the Russian abbreviation for Центра́льный аэрогидродинами́ческий институ́т or "Tsentralniy Aerogidrodinamicheskiy Institut", the Central Aerohydrodynamic Institute....

 with a requirement for a heavy bomber with total engine output of 2,000 PS
Horsepower
Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...

 (1,970 hp
Horsepower
Horsepower is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the...

) and either wheeled or float landing gear. Tupolev
Tupolev
Tupolev is a Russian aerospace and defence company, headquartered in Basmanny District, Central Administrative Okrug, Moscow. Known officially as Public Stock Company Tupolev, it is the successor of the Tupolev OKB or Tupolev Design Bureau headed by the Soviet aerospace engineer A.N. Tupolev...

 OKB
OKB
OKB is a transliteration of the Russian acronym for "Опытное конструкторское бюро" - Opytnoe Konstructorskoe Byuro, meaning Experimental Design Bureau...

 started design work in 1926 with the government operational requirements finalized in 1929. Tupolev TB-1
Tupolev TB-1
-See also:-References:* Duffy, Paul and Andrei Kandalov. Tupolev: The Man and His Aircraft. Shrewsbury, UK:Airlife Publishing, 1996. ISBN 1 85310 728 X....

 was taken as the basis for the design and the aircraft was initially powered by Curtiss V-1570
Curtiss V-1570
|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9-External links:...

 "Conqueror" engines generating 600 PS (590 hp) each, with the intent of switching to Mikulin M-17
Mikulin M-17
-See also:-External links:* http://avia.russian.ee/air/russia/index.html...

s (modified BMW VI
BMW VI
|-See also:- External links :...

s) in production. The mock-up was approved on 21 March 1930 and the first prototype was completed on 31 October 1930. The aircraft flew on 22 December 1930 with Mikhail Gromov
Mikhail Gromov (aviator)
Mikhail Mikhaylovich Gromov was a famous Russian aviator and Hero of the Soviet Union.On 12-14 July 1937, Mikhail Gromov, A. B. Yumashev and S. A...

 at the controls and with ski
Ski
A ski is a long, flat device worn on the foot, usually attached through a boot, designed to help the wearer slide smoothly over snow. Originally intended as an aid to travel in snowy regions, they are now mainly used for recreational and sporting purposes...

 landing gear, despite almost crashing owing to vibration causing the throttles to close, the test flight was a success. On 20 February 1931, the Soviet Air Force approved mass production of ANT-6 with M-17 engines.

The prototype was refitted with BMW VIz 500 engines of 730 PS (720 hp) each, larger radiators, and wooden fixed-pitch propellers of TsAGI design. Single-wheel landing gear was deemed too weak and was replaced by tandem
Tandem
Tandem is an arrangement where a team of machines, animals or people are lined up one behind another, all facing in the same direction....

 bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...

s with 1,350×300 mm (53×12 in
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...

) tires. The first pre-production TB-3-4M-17 flew on 4 January 1932 with A. B. Yumashev and I. F. Petrov at the controls. Unexpectedly, subsequent mass-produced aircraft were found to be 10-12% heavier than the prototype which significantly hampered performance. The discrepancy was discovered to be due to high positive tolerances on raw materials which resulted in steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 sheetmetal, pipes, and wires being much thicker than on the carefully constructed prototypes. The aircraft were also more crudely painted with a thick layer of camouflage and lacquer. The factories asked the workers for suggestions on reducing the weight, paying 100 roubles for each kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...

 (2.2 lb
Pound (mass)
The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...

) removed from the aircraft. In combination with OKB efforts, this resulted in weight savings of almost 1000 kilograms (2,204.6 lb). Despite this, production aircraft could differ from each other by as much as several hundred kilograms.

In 1933, a single TB-3-4M-17F was streamline
Streamliner
A streamliner is a vehicle incorporating streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor "bullet trains". Less commonly, the term is applied to fully faired recumbent bicycles...

d with removal of turret
Turret
In architecture, a turret is a small tower that projects vertically from the wall of a building such as a medieval castle. Turrets were used to provide a projecting defensive position allowing covering fire to the adjacent wall in the days of military fortification...

s and bomb
Bomb
A bomb is any of a range of explosive weapons that only rely on the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy...

 shackle
Shackle
A shackle, also known as a gyve, is a U-shaped piece of metal secured with a clevis pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism...

s, covering of all openings, and fitting of wheel spats. This resulted in only a 4.5% increase in top speed and a similar increase in the range. Tupolev concluded that streamlining was minimally beneficial for large and slow aircraft
Slow flight
Slow flight is a portion of an airplane's performance envelope above the speed at which the plane will stall, but below the aircraft's endurance speed. This part of the performance chart is also known as "the back side of the power curve" because when flying in this area, more power is required in...

. To study the effect of corrugated skin, in January–February 1935 a single TB-3-4AM-34R had the corrugations incrementally covered with fabric. This resulted in a 5.5% gain in top speed and a 27.5% increase in the ceiling. The same aircraft demonstrated a significant increase in climb rate
Rate of climb
In aeronautics, the rate of climb is an aircraft's vertical speed - the rate of change in altitude. In most ICAO member countries , this is usually expressed in feet per minute and can be abbreviated as ft/min. Elsewhere, it is commonly expressed in metres per second, abbreviated as m/s...

 when fitted with experimental four-blade propeller
Single-blade propeller
A single-blade propeller may be used on aircraft to generate thrust. Normally propellers are multiblades but the simplicity of a single-blade propeller fits well on motorized gliders, because it permits the design of a smaller aperture of the glider fuselage for retraction of the powerplant...

s.

Record flights
  • TB-3-4M-34R set a flight endurance record of 18 hours and 30 minutes.
  • TB-3-4AM-34FRN with A. B. Yumashev at the controls set a number of payload-to-altitude records:
    • 11 September 1936 - 5000 kilograms (11,023.1 lb) to 8116 metres (26,627.3 ft), improved to 8980 metres (29,461.9 ft) on 28 October.
    • 16 September 1936 - 10000 kilograms (22,046.2 lb) to 6605 metres (21,669.9 ft)
    • 20 September 1936 - 12000 kilograms (26,455.5 lb) to 2700 metres (8,858.3 ft)

Design

The TB-3 was an all-metal aircraft of steel construction. The frame was composed of V-section beam
Beam (nautical)
The beam of a ship is its width at the widest point. Generally speaking, the wider the beam of a ship , the more initial stability it has, at expense of reserve stability in the event of a capsize, where more energy is required to right the vessel from its inverted position...

s covered with non-stressed corrugated skin ranging from 0.3 to 0.8 mm (1/64 to 1/32 in) in thickness. The corrugations were 13 mm deep (0.51 in) and 50 millimetres (2 in) apart. The cantilever wing was supported by four tube-section spar
Spar
In sailing, a spar is a pole of wood, metal or lightweight materials such as carbon fiber used on a sailing vessel. Spars of all types In sailing, a spar is a pole of wood, metal or lightweight materials such as carbon fiber used on a sailing vessel. Spars of all types In sailing, a spar is a...

s. In 1934, thanks to development of stronger steel alloy
High speed steel
High speed steelMost copyeditors today would tend to choose to style the unit adjective high-speed with a hyphen, rendering the full term as high-speed steel, and this styling is not uncommon . However, it is true that in the metalworking industries the styling high speed steel is long-established...

s, wingspan
Wingspan
The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...

 was increased from 39.5 to 41.85 m (129.6 to 137.3 ft) with a concurrent wing area increase from 230 to 234.5 m² (2,475 to 2,524 ft²). Any part of the aircraft could be walked on in soft shoes without damaging the skin, and the leading edge
Leading edge
The leading edge is the part of the wing that first contacts the air; alternatively it is the foremost edge of an airfoil section. The first is an aerodynamic definition, the second a structural one....

s of the wings swung down to form walkways for engine maintenance. Controls were cable-actuated with a variable-incidence tailplane
Tailplane
A tailplane, also known as horizontal stabilizer , is a small lifting surface located on the tail behind the main lifting surfaces of a fixed-wing aircraft as well as other non-fixed wing aircraft such as helicopters and gyroplanes...

 and a trim compensation system in case of engine failures on one side. Fixed main landing gear
Landing Gear
Landing Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...

 was not fitted with brakes. The fuel tank
Fuel tank
A fuel tank is safe container for flammable fluids. Though any storage tank for fuel may be so called, the term is typically applied to part of an engine system in which the fuel is stored and propelled or released into an engine...

s did not have fire or leak protection, although the engines had an internal fire-extinguishing system. The M-17 engines were tuned to provide a maximum theoretical range of 3250 km (1,754.9 nmi; 2,019.5 mi) without spark plug or carburetor
Carburetor
A carburetor , carburettor, or carburetter is a device that blends air and fuel for an internal combustion engine. It is sometimes shortened to carb in North America and the United Kingdom....

 fouling
Fouling
Fouling refers to the accumulation of unwanted material on solid surfaces, most often in an aquatic environment. The fouling material can consist of either living organisms or a non-living substance...

. Defensive armament consisted of light machine gun
Light machine gun
A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...

s in five turret
Turret
In architecture, a turret is a small tower that projects vertically from the wall of a building such as a medieval castle. Turrets were used to provide a projecting defensive position allowing covering fire to the adjacent wall in the days of military fortification...

s — one in the nose, two on top of mid-fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...

, and one retractable "dustbin" under each wing between the engine nacelle
Nacelle
The nacelle is a cover housing that holds engines, fuel, or equipment on an aircraft. In some cases—for instance in the typical "Farman" type "pusher" aircraft, or the World War II-era P-38 Lightning—an aircraft's cockpit may also be housed in a nacelle, which essentially fills the...

s. Later variants moved one of the top fuselage turrets aft
Aft
Aft, in naval terminology, is an adjective or adverb meaning, towards the stern of the ship, when the frame of reference is within the ship. Example: "Able Seaman Smith; lay aft!". Or; "What's happening aft?"...

 of the tail fin.

Operational history

The TB-3 was used operationally during the Battle of Khalkhin Gol
Battle of Khalkhin Gol
The Battles of Khalkhyn Gol was the decisive engagement of the undeclared Soviet–Japanese Border Wars fought among the Soviet Union, Mongolia and the Empire of Japan in 1939. The conflict was named after the river Khalkhyn Gol, which passes through the battlefield...

 and in the Winter War
Winter War
The Winter War was a military conflict between the Soviet Union and Finland. It began with a Soviet offensive on 30 November 1939 – three months after the start of World War II and the Soviet invasion of Poland – and ended on 13 March 1940 with the Moscow Peace Treaty...

 with Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

. Although it was officially withdrawn from service in 1939, at the start of the Great Patriotic War on 22 June 1941, the Soviet Air Force
Soviet Air Force
The Soviet Air Force, officially known in Russian as Военно-воздушные силы or Voenno-Vozdushnye Sily and often abbreviated VVS was the official designation of one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces...

 had 516 operational TB-3s, with an additional 25 operated by the Soviet Navy
Soviet Navy
The Soviet Navy was the naval arm of the Soviet Armed Forces. Often referred to as the Red Fleet, the Soviet Navy would have played an instrumental role in a Warsaw Pact war with NATO, where it would have attempted to prevent naval convoys from bringing reinforcements across the Atlantic Ocean...

. Stationed far from the USSR's western border, the ТB-3s avoided catastrophic losses during the first German air strikes, after which TB-3s from 3rd TBAP (Heavy Bomber Regiment) began flying night bombing missions on 23 June. Shortage of combat-ready aircraft also required daytime use of TB-3s without fighter escort and in this role the bombers, operating at low-to-medium altitudes, suffered heavy losses to enemy fighters and ground fire. By August 1941, TB-3s made up 25% of the Soviet bomber force and, operated by elite air force crews, were flying up to three combat missions per night. The aircraft participated in all major battles through 1943, including the first Battle of Smolensk
Battle of Smolensk (1941)
The Battle of Smolensk was a largely successful encirclement operation by the German Army Group Centre's 2nd Panzer Group led by Heinz Guderian and the 3rd Panzer Group led by Hermann Hoth against parts of four Soviet Fronts during World War II...

, the Battle of Moscow
Battle of Moscow
The Battle of Moscow is the name given by Soviet historians to two periods of strategically significant fighting on a sector of the Eastern Front during World War II. It took place between October 1941 and January 1942. The Soviet defensive effort frustrated Hitler's attack on Moscow, capital of...

, the Battle of Stalingrad
Battle of Stalingrad
The Battle of Stalingrad was a major battle of World War II in which Nazi Germany and its allies fought the Soviet Union for control of the city of Stalingrad in southwestern Russia. The battle took place between 23 August 1942 and 2 February 1943...

, the Siege of Leningrad
Siege of Leningrad
The Siege of Leningrad, also known as the Leningrad Blockade was a prolonged military operation resulting from the failure of the German Army Group North to capture Leningrad, now known as Saint Petersburg, in the Eastern Front theatre of World War II. It started on 8 September 1941, when the last...

, and the Battle of Kursk
Battle of Kursk
The Battle of Kursk took place when German and Soviet forces confronted each other on the Eastern Front during World War II in the vicinity of the city of Kursk, in the Soviet Union in July and August 1943. It remains both the largest series of armored clashes, including the Battle of Prokhorovka,...

. On 1 July 1945, 18th Air Army still had ten TB-3s on the active roster.

The TB-3 served extensively as a cargo and paratroop transport, carrying up to 35 soldiers in the latter role. In the first five months of the war, the aircraft transported 2,797 tons of cargo and 2,300 personnel.

The TB-3 was also used in several special projects as a fighter mothership in the Zveno project
Zveno project
Zveno was a parasite aircraft concept developed in the Soviet Union during the 1930s. It consisted of a Tupolev TB-1 or a Tupolev TB-3 heavy bomber acting as a mothership for between two and five fighters...

 and for delivering light T-27
T-27
The T-27 was a tankette produced in the 1930s by the Soviet Union. It was based on the design of the Carden Loyd tankette, bought under license from the United Kingdom in 1930.-Design:...

, T-37
T-37 tank
The T-37A was a Soviet amphibious light tank. The tank is often referred to as the T-37, although that designation was used by a different tank which never left the prototype stage.The T-37A was the first series of mass-produced fully amphibious tanks in the world.The tank was first created in...

. and T-38 tanks. On 1 August 1941, a pair of TB-3s in Zveno-SPB configuration, each with two Polikarpov I-16
Polikarpov I-16
The Polikarpov I-16 was a Soviet fighter aircraft of revolutionary design; it was the world's first cantilever-winged monoplane fighter with retractable landing gear. The I-16 was introduced in the mid-1930s and formed the backbone of the Soviet Air Force at the beginning of World War II...

 fighters carrying a pair of 250 kilograms (551.2 lb) bombs, destroyed an oil depot with no losses. On 11 August and 13 August 1941, Zveno-SPB successfully damaged the King Carol I Bridge
King Carol I Bridge
The Anghel Saligny Bridge was built between 1890 and 1895 in Romania over the Danube and Borcea branch of the Danube, and when it was completed it then became the longest bridge in Europe and the third longest in the world...

 over Danube
Danube
The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

 in Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

. Zveno operations ended in the fall of 1942 due to high vulnerability of the motherships.

In recognition of the role TB-3 played during the war, three aircraft were included in the first post-war air parade on 18 June 1945.

Variants

Source: Shavrov
TB-3-4M-17F
The first production version, comprised about half of all TB-3s built.

TB-3-4M-34
Mikulin AM-34
Mikulin AM-34
The Mikulin AM-34 was the Soviet Union’s first indigenous mass-produced, liquid-cooled, aircraft engine. Its initial development was troubled, but it eventually became one of the most successful Soviet aircraft engines of the 1930s...

 engines with revised radiators, added oil coolers, several dozen built.

TB-3-4M-34R
Mikulin AM-34R engines with reduction gearboxes providing significantly improved performance, additional turret aft of the tail fin, tail wheels with hydraulic brakes, aerodynamic refinements of the wing-fuselage join and radiators, retractable wind generators.

TB-3-4AM-34RD
A series of long-range demonstration aircraft with streamlined fuselages and wheel brakes. Some aircraft had single main gear wheels 2 metres (6.6 ft) in diameter and three-blade metal propellers. Used for flights to Warsaw
Warsaw
Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...

, Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

, and Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

 in 1933-1934.

TB-3-4AM-34RN
High-altitude version with AM-34RN engines, four-blade propellers on inboard engines and two-blade on outboard, 2 metres (6.6 ft) single main wheels, turrets upgraded to ShKAS machine gun
ShKAS machine gun
The ShKAS is a 7.62 mm machine gun widely used by Soviet aircraft in the 1930s and during World War II...

s, top speed 288 km/h (147 kn; 179 mph) at 4200 metres (13,779.5 ft), service ceiling 7740 metres (25,393.7 ft). Tested in August–October 1935 but did not enter production as the basic TB-3 design was becoming obsolete.

TB-3-4AM-34FRN/FRNV
AM-34FRN/FRNV engines with increased power output and four-blade propellers, aerodynamic refinements including streamlined turrets, 2 metres (6.6 ft) main wheels with brakes, top speed over 300 km/h (153.1 kn; 186.4 mph).

TB-3D
Proposed variant with Charomsky AN-1 diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

s of 750 PS (740 hp) and projected range of 4,280 km (2,310 nm, 2,660 mi), did not enter production as other performance characteristics were inferior to TB-3-4AM-34RN.

G-2
Retired TB-3s with M-17 and M-34 engines converted for freight duties with Aeroflot
Aeroflot
OJSC AeroflotRussian Airlines , commonly known as Aeroflot , is the flag carrier and largest airline of the Russian Federation, based on passengers carried per year...


ANT-6-4M-34R "Aviaarktika"
TB-3 modified for the 1937 expedition to the North Pole
North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets its surface...

 with enclosed cockpit, single 2 metres (6.6 ft) main wheels, three-blade metal propellers.

Operators

  • Nationalist China Air Force

  • Aeroflot
    Aeroflot
    OJSC AeroflotRussian Airlines , commonly known as Aeroflot , is the flag carrier and largest airline of the Russian Federation, based on passengers carried per year...

  • Soviet Air Force
    Soviet Air Force
    The Soviet Air Force, officially known in Russian as Военно-воздушные силы or Voenno-Vozdushnye Sily and often abbreviated VVS was the official designation of one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces...


Specifications (TB-3-4M-17F, 1934 model)

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