The Tupolev Tu-12 (development designation Tu-77) was an experimental
Soviet
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...
jet-powered medium bomber developed from the successful piston-engined
Tupolev Tu-2
The Tupolev Tu-2 (development names ANT-58 and 103; NATO reporting name Bat) was a twin-engine Soviet high-speed daylight and frontline (SDB and FB) bomber aircraft of World War II vintage. The Tu-2 was tailored to meet a requirement for a high ...
bomber after the end of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. It was designed as a transitional aircraft to familiarize
Tupolev
Tupolev (russian: Ту́полев, ), officially Joint Stock Company Tupolev, is a Russian aerospace and defence company headquartered in Basmanny District, Moscow.
Tupolev is successor to the Soviet Tupolev Design Bureau (OKB-156, design off ...
and the
VVS with the issues involved with jet-engined bombers.
Development
The
Tupolev Tu-73
The Tupolev '73', (''samolyot'' 73), was a Soviet trijet medium bomber of the late 1940s. It lost out to the Ilyushin Il-28 'Beagle'.
Development
The Tupolev OKB continued to develop the Tu-2 line with the advent of gas turbine power-plants. The ...
jet-engined bomber project was suffering delays in early 1947 and Tupolev suggested re-engining the Tu-2 medium bomber with imported British
Rolls-Royce Nene
The Rolls-Royce RB.41 Nene is a 1940s British centrifugal compressor turbojet engine. The Nene was a complete redesign, rather than a scaled-up Rolls-Royce Derwent"Rolls-Royce Aero Engines" Bill Gunston, Patrick Stephens Limited 1989, , p.111 w ...
jet engines to produce a jet bomber as quickly as possible. Design work began well before official approval was received on 31 May 1947 for one Tu-2S to be converted in the OKB's workshop and another five to be converted at Zavod (Factory) Nr. 23, but construction of the prototype had already begun in early May under the bureau designation Tu-77.
Changes from the standard Tu-2 were minimized to speed production and they consisted of the following:
[Gordon & Rigamant, p. 118]
* Two Nene jet engines replaced the standard
Shvetsov ASh-82
The Shvetsov ASh-82 (M-82) is a Soviet 14-cylinder, two-row, air-cooled radial aircraft engine developed from the Shvetsov M-62. The M-62 was the result of development of the M-25, which was a licensed version of the Wright R-1820 Cyclone.
Desi ...
FN
radial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...
s.
* The wing
dihedral was reduced to 3° from 6°.
* The fuselage was lengthened and the rear fuselage was heightened by .
* A new tricycle
undercarriage
Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include:
*The landing gear of an aircraft.
*The ch ...
was fitted, with the main gear units retracting into the engine nacelles.
* Additional fuel tanks were fitted and the design of the tanks was changed to accommodate the change from
gasoline
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...
to
kerosene
Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...
.
* The control system was revised and
trim tab
Trim tabs are small surfaces connected to the trailing edge of a larger control surface on a boat or aircraft, used to control the trim of the controls, i.e. to counteract hydro- or aerodynamic forces and stabilise the boat or aircraft in a pa ...
s were fitted to the
elevators
An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They are ...
.
* The wing and tail were reinforced.
* The
ShVAK cannon
The ShVAK ( ru , ШВАК: Шпитальный-Владимиров Авиационный Крупнокалиберный, Shpitalnyi-Vladimirov Aviatsionnyi Krupnokalibernyi, "Shpitalny-Vladimirov Aviation Large-calibre") was a 20 mm autocann ...
were removed from the
wing root
The wing root is the part of the wing on a fixed-wing aircraft or winged-spaceship that is closest to the fuselage,Peppler, I.L.: ''From The Ground Up'', page 9. Aviation Publishers Co. Limited, Ottawa Ontario, Twenty Seventh Revised Edition, 1996 ...
s and a
Nudelman-Suranov NS-23
The NS-23 was a aircraft cannon designed by A. E. Nudelman, A. Suranov, G. Zhirnykh, V. Nemenov, S. Lunin, and M. Bundin during World War II as a replacement for the Volkov-Yartsev VYa-23 cannon. It entered service in 1944. The NS-23 round was d ...
cannon was mounted in an external fairing on the starboard side of the nose.
Testing and evaluation
The prototype was completed in July and was first flown on 27 July 1947. Two aircraft were shown at the
Tushino Aviation Day parade
In the life of Soviet Union, air shows were a highly regarded type of parade, almost always of military nature. They happened on various occasions and anniversaries, in many locations across the country. A notable air show was the Tushino Air Show ...
on 3 August 1947. It completed manufacturer's trials in September and underwent the state acceptance trials from 4 October 1947 to 27 February 1948 when it was redesignated as the Tu-12. The NII VVS (''Naoochno-Issledovatel'skiy Institoot Voyenno-Vozdooshnykh Seel'' – Air Force Scientific Test Institute) report summarized the differences between the Tu-2 and Tu-12 as "a considerable gain in speed, an improved rate of climb, a higher service ceiling, but poorer field performance and a considerably greater fuel load required to achieve the same range as the Tu-2."
[Gordon & Rigamant, p. 120] Both the lack of a pressurized cabin that greatly reduced its effectiveness at high altitude and the lack of
deicing
Deicing is the process of removing snow, ice or frost from a surface. Anti-icing is the application of chemicals that not only deice but also remain on a surface and continue to delay the reformation of ice for a certain period of time, or preve ...
equipment for the wing and tail leading edges and the cockpit glazing were noted as major problems. At high speeds it was virtually impossible to traverse and elevate the manually-operated VUB-68 and Lu-68 gun turrets. The vibration of the NS-23 cannon when firing rendered the equipment in the navigator's cabin unusable and damaged the cabin glazing. Turning on the
Identification friend or foe (IFF) system adversely affected the intercom system and the radios. New generators had to be installed as the originals did not produce enough electrical power.
[
The trials conducted by the NII VVS included engagements between the Tu-12 and the Soviet ]MiG-9
The Mikoyan-Gurevich MiG-9 (russian: Микоян и Гуревич МиГ-9, USAF/DoD designation: Type 1, NATO reporting name: Fargo) was the first turbojet fighter developed by Mikoyan-Gurevich in the years immediately after World War II. ...
and Yak-23
The Yakovlev Yak-23 (russian: Яковлев Як-23; USAF/DoD reporting name Type 28, NATO reporting name Flora) was an early Soviet Union, Soviet jet engine, jet Fighter aircraft, fighter with a straight wing. It was developed from the Yakovlev ...
jet fighters which were very useful in evaluating the offensive armament of the fighters, the defensive armament of the bomber and the proper tactics involved for both types of aircraft. The tests demonstrated the inferiority of the current armament and meant that every Soviet bomber henceforth would have a defensive armament using power-operated turrets that carried 20 mm or larger guns.[
The five aircraft modified by the factory were given the Klimov RD-45 engine, the Soviet unlicensed copy of the Nene engine, and all six aircraft were used by the VVS for aircrew familiarization and training. The aircraft completed were later relegated to test duties. One aircraft was used for drone tests and another, redesignated as the Tu-12LL, mounted various ]pulse jet engine
300px, Diagram of a pulsejet
A pulsejet engine (or pulse jet) is a type of jet engine in which combustion occurs in pulses. A pulsejet engine can be made with few or no moving parts, and is capable of running statically (i.e. it does not need t ...
s on a pylon above the fuselage.[Gunston 1995b, p. 137]
Operators
;
*Soviet Air Force
The Soviet Air Forces ( rus, Военно-воздушные силы, r=Voyenno-vozdushnyye sily, VVS; literally "Military Air Forces") were one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces. The Air Forces ...
Specifications (Tu-12)
References
Notes
Bibliography
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*
*
{{good article
1940s Soviet bomber aircraft
Tu-0012
Twinjets
Aircraft first flown in 1947