Tupolev Tu-4

From Wikipedia, the free encyclopedia

Tupolev Tu-4
Tupolev Tu-4 at Monino museum
Type	Strategic bomber
Manufacturer	Tupolev
Maiden flight	19 May 1947
Status	Out of service
Primary users	Soviet Air Force PLA Air Force
Produced	1949-1952
Number built	847
Developed from	B-29 Superfortress

The Tupolev Tu-4 (NATO reporting name: Bull) was a piston-engined Soviet strategic bomber which served the Soviet Air Force from the late 1940s to mid 1960s. It was a reverse-engineered copy of the US-made Boeing B-29 Superfortress.

Contents 1 Development 2 Operational history 3 Specifications (Tu-4) 4 References 5 Related content

[edit] Development

Towards the end of World War II, the Soviet Union was envious of the strategic bombing capability of the USAAF. The U.S. regularly conducted bombing raids on Japan, virtually in the Soviet Union's backyard, from distant Pacific forward bases using B-29 Superfortresses. Stalin ordered the development of a comparable bomber.

During 1944, after bombing raids on Japanese Manchuria and Japan, three B-29s were forced (on three different occasions) to land in Soviet territory due to emergencies. The Soviets seized the bombers, and Tupolev OKB dismantled and studied them. Stalin ordered Tupolev and his design bureau to copy the interned B-29s down to their smallest details, and produce a design ready for quantity production as soon as possible. Tupolev duly copied the B-29s bolt-by-bolt where possible, reverse-engineering the design where necessary.

The last B-29 seized by the Soviets was built in Kansas during a shortage of chromate green (a common corrosion-proofing paint for aircraft of the time). White lead was substituted as a "quick fix," which was promptly institutionalized by the duplicators. Even repair patch panels on the B-29s (used to cover anti-aircraft or other damage) were faithfully duplicated on the first Tu-4, as failure to duplicate even non-essential or useless characteristics of the B-29 could be interpreted as a refusal to comply with Stalin's orders to reproduce the B-29 in exact detail. Others have speculated that Tupolev and others at the design bureau added the patches as an ironic joke, irritated at having to essentially copy the B-29 by rote. Additionally, as 1/16th-inch-thick sheet aluminum and corresponding rivet lengths were unavailable in the metric Soviet Union, thicker panels were used and selectively milled to the corresponding proper gauge. The result was an aircraft that weighed somewhat more than the B-29 prototype, giving it less range and payload. Another example of how closely the "copies" matched the original B-29's were the control pedals that still had "Boeing" cast into them.

The resulting bomber was the Tu-4, which first flew on 19 May 1947. Serial production started immediately, and the type entered large scale service in 1949. Entry into service of the Tu-4 threw the USAF into a virtual panic, since the Tu-4 possessed sufficient range to attack Chicago, Los Angeles, and New York City with a worthwhile load on a one-way mission. Some limited attempts to develop midair refueling systems were made to extend the bomber's range, but these were fitted to few aircraft.

[edit] Operational history

847 Tu-4s were built in the Soviet Union by the time production ended in 1952, with some going to China during the later 1950s. Many experimental variants were built and the valuable experience launched the Soviet strategic bomber program. Tu-4s were withdrawn in the 1960s, replaced by their more capable successors, the Tupolev Tu-95 (starting in 1956) and Tupolev Tu-16 (starting in 1954). At the beginning of the 1960s, the only remaining Tu-4s in Soviet use were used in transport aviation and as airborne laboratories. There is at least one confirmed Soviet Tu-4 surviving. It is located at The Monino Air Force Museum, which is located on the grounds of the Yuri Gagarin Air Force Academy, outside Moscow. There are unconfirmed reports of two additional Tu-4s at The Peoples Air Museum. Unconfirmed rumors also claim the existence of at least 15 other Tu-4 airframes somewhere in Russia.

Two Soviet-built Tu-4s survive at the National Air Museum near Beijing, China. One of these aircraft has been converted to an AWACS testbed KJ-1 referred as KJ-1 AEWC, the other carries an unmanned spy plane under each wing; both aircraft have been upgraded with 4,000hp Ivchenko AI-20K turboprops. However, there are rumors that as many as 15 Tu-4s are still in service with the Chinese People's Liberation Army Air Force.

A few derivatives were planned, including an airliner (Tu-70), cargo plane (Tu-75), and refined versions of the basic bomber (Tu-80 and Tu-85), but none of these reached mass production.

[edit] Specifications (Tu-4)

General characteristics

• Crew: 11
• Length: 30.18 m (99 ft)
• Wingspan: 43.05 m (141 ft)
• Height: 8.46 m (27 ft)
• Wing area: 161.7 m² (1,743 ft²)
• Empty weight: 35,270 kg (77,594 lb)
• Loaded weight: 46,700 kg (102,950 lb)
• Max takeoff weight: 65,000 kg (143,000 lb)
• Powerplant: 4× Shvetsov ASh-73TK radial engines, 1,790 kW (2,400 hp) each

Performance

• Maximum speed: 558 km/h at 10,250 m (33,600 ft) (349 mph)
• Range: 6,200 km (with 3,000 kg (6,600 lb) bomb load) (3,875 mi)
• Service ceiling: 11,200 m (36,700 ft)
• Rate of climb: m/s (ft/min)
• Wing loading: 400 kg/m² (82 lb/ft²)
• Power/mass: 0.11 kW/kg (0.07 hp/lb)

Armament

• Guns: 10× 23 mm Nudelman NS-23 aircraft cannons, two each in four turrets and tail barbette
• Bombs:
  • 6× 1,000 kg (2,200 lb) bombs or
  • 1× atomic bomb (Tu-4A) or
  • 2× KS-1 standoff missiles (Tu-4K)

[edit] References

• Tu-4 Photos at airliners.net, including PLAAF examples.

[edit] Related content

Related development

• B-29 Superfortress
• Tupolev Tu-70
• Tupolev Tu-75
• Tupolev Tu-80
• Tupolev Tu-85

Comparable aircraft

• B-32 Dominator
• Avro Lincoln
• Messerschmitt Me 264

Designation sequence

• Tu-1 - Tu-2 - Tu-4 - Tu-6 - Tu-8 - Tu-10 - Tu-12 - Tu-14

Related lists

• List of bomber aircraft
• List of military aircraft of the Soviet Union and the CIS

See also