The Tu-4 Grows Up
By the end of the 1940s, the development of turbine engines had marked the closing of the piston era. Initially, the new turbojets were small, and were not of any use for long-range bombers, but by the early 1950s they had started to develop. So had turboprops.
In the West, the turboprop was confined mainly to commercial aircraft the Bristol Britannia, Vickers Viscount and Lockheed Electra helped to bridge a gap between the piston and jet ages. Some military transports would use turboprops. Particularly well-known is the Lockheed Hercules, and a few mainly carrier-borne strike aircraft such as the Fairey Gannet. But little thought was given to the possibility of using turboprops to power strategic bombers by anyone except Tupolev and his team.
In 1949, he set up a team headed by Nikolai Bazenkov to develop the Tu-85 and make use of the new developments in Soviet turboprops, specifically Nikolai Kuznetsov’s new NK-12, due to be available in 1953, which offered a power of up to 15,000 shaft horsepower (shp). Pending their availability, development work began using TV-2 and TV-12 engines of 12,000shpeach.
Two prototypes were constructed in factory N156 beside the design offices, using, as usual, the design bureau’s specialist engineers working alongside Bazenkov and his team, with Tupolev visiting the works almost every day as was the norm. Although substantially based on the Tu-85, a considerable amount of work was needed to adapt the design for the much higher speeds targeted for the Tu-95. Most important was the wing; the Tu-85 had a maximum speed of 563kph/350mph, but the -95 was expected to achieve 900 to 950kph/559 to 590mph, almost sixty to seventy per cent faster. In an effort to achieve this, Bazenkov developed a wing which measured 51m/167.33 feet from tip to tip, despite a 35° angle of sweep. The 6m/l 9.7-foot-long engines were installed in large nacelles on the wings, with the inner ones having a pod which extended eight metres to the rear into which the four-wheeled undercarriage legs retracted rearwards.
The cabin was pressurised, which improved crew conditions on long-distance flights — cruising at 750kph/466mph, patrols could last up to twenty hours. One thing missing was ejection seats. Although normal equipment in most high-performance military aircraft since the late 1940s, the Tu-95 did not have them. The crew in the forward section had to evacuate by using an emergency lift which would bring them from the cockpit and drop them through a hatch near the nosewheel door while those in the aircraft’s tail exited through escape hatches.
The prototype Tu-95 (called Tu-95/1) was completed by September 1952, and was brought by road to Zhukovski. After reassembly, it began its ground trials early in November; on 12 November, with Aleksei Pereliot in command, the first flight took place. As mentioned earlier, its engines were the 12,000shp TV-2FS. In state tests, they exceeded 900kph/559mph, something considered impossible by many aerodynamic specialists for propeller aircraft. Tupolev gave particular credit for the excellent performance to the design and production of Konstantin Zhdanov’s propeller and gearbox developed at Stupino, near Moscow.
Work proceeded on the second prototype relatively slowly, but late in 1953 the first aircraft crashed due to an engine fire which resulted in the engine falling off. Three people died: Pereliot, a flight engineer and a research scientist; nine escaped by evacuating the aircraft by parachute. The second was completed only in July 1954. Delays in engine production meant that it did not receive its TV-12s until the end of the year. Early in 1955, the Tu-95/2 was rolled out at Zhukovski for its pre-flight trials, including engine runs and taxying tests. It made its first flight on 16 February, flown by Mikhail Nukhtikov.
Meanwhile, serial production of the Tu-20, as the VVS designated it, had been set up at Kuibyshev factory N18 under General Director Mitrofan Yevshin. Work started in January 1955 and the first two production aircraft were completed in October and began state tests. They were powered by the first production examples of Kuznetsov’s NK-12, which gave 12,000shp. As was usual in the Soviet system, production examples were not built to the same standards as the virtually hand-made prototypes, and Soviet designers made allowances for this. The production Tu-95, with lower powered engines and higher weight, was measured to have a performance of 882kph/548mph in speed, a range with a five tonne payload of 15,040km/9,346 miles, and a service ceiling of 11,300m/37,075 feet – not quite up to VVS requirements. The second production aircraft was fitted with the NK-12M, a higher powered version which gave 15,000sph and a lower fuel consumption. With these, performance improved to a maximum speed of 905kph/562mph, range to 16,750km/10,408 miles, and ceiling to 12,150m/39,864 feet. These figures met the requirements.
The Tu-95 was first shown to the public at the 1955 Aviation Day air show at Tushino, in Moscow’s north-west, in August, when the second prototype made a flypast. The VVS accepted delivery of its first Tu-95s in August 1957, and it went into service as a long-range strategic bomber. It was armed with six pairs of AM-23 cannons, providing almost complete coverage: one pair was in the nose, two above the fuselage, just behind the cockpit and forward of the tail, one was in a tail turret and the others under the fuselage. Some of these could be remotely operated by a gunner who sat between two glazed blisters in the rear fuselage. The bomb load varied from a maximum range version with five tonnes to fifteen tonnes with a fall off in range; it was possible to carry two nuclear bombs, or conventional warheads.
An accident in March 1957, when the failure of one engine plus a problem in propeller feathering caused the loss of the aircraft and the death of the crew, resulted in the installation of NK-12MVs, modified versions of the engine with automatic and manual systems of feathering. Production of the Tu-95 continued until 1959, in several different versions listed below.
Production totalled 173 aircraft plus the two prototypes. All these were strategic aircraft. While most of them continued in service until the late 1980s/early 1990s, the effects of the Strategic Arms Limitations Talks (SALT) caused many of them to be cut up in the 1990s. Some of the Tu-95s – or, to give them their worthy NATO codename, Bear – were modified after their withdrawal from front-line bomber units to carry missiles or for reconnaissance roles. Two Tu-95s were removed from the production line in 1958 and were completed as Tu-116s. By the mid-1990s all Tu-95s were grounded or scrapped.
Later, the Tu-95 would appear again as the nonstrategic Tu-142. Although differing mainly in equipment from the Tu-95, the -142 was not a bomber, and so did not come under the auspices of the SALT treaty. Its story is related later.
A Tu-95 was modified as a Tu-95LAL (=Letavshaia Atomnaia Laboratoriya = Flying Atomic laboratory). Although no engine power was generated from atomic sources, the aircraft carried a VVR-100 reactor, and made 42 flights to test ecological problems; after these tests, the decision was taken not to proceed with the Tu-119 which remained a paper project.
The first prototype powered by Kuznetsov 2TV-2F coupled turboprop engines.
The second prototype powered by Kuznetsov NK-12 turboprops.
Basic variant of the long-range strategic bomber and the only model of the aircraft never fitted with a nose refuelling probe. Known to NATO as the Bear-A.
Experimental version for air-dropping a MiG-19 SM-20 jet aircraft.
Conversions of the older Bear bombers, reconfigured to carry the Raduga Kh-22 missile and incorporating modern avionics. Known to NATO as the Bear-G.
Designed to carry the Kh-20 air-to-surface missile. The Tu-95KD aircraft were the first to be outfitted with nose probes. Known to NATO as the Bear-B.
Modified and upgraded versions of the Tu-95K, most notable for their enhanced reconnaissance systems. These were in turn converted into the Bear-G configuration. Known to NATO as the Bear-C.
Experimental nuclear-powered aircraft project.
Modification of the serial Tu-95 with the NK-12M engines. 19 were built.
Bear-A modified for photo-reconnaissance and produced for Naval Aviation. Known to NATO as the Bear-E.
Completely new cruise missile carrier platform based on the Tu-142 airframe. This variant became the launch platform of the Raduga Kh-55 cruise missile and put into serial production in 1981. Known to NATO as the Bear-H and was referred to by the U.S. military as a Tu-142 for some time in the 1980s before its true designation became known.
Capable of carrying six Kh-55, Kh-55SM or Kh-555 cruise missiles on a rotary launcher in the aircraft’s weapons bay. 32 were built.
Fitted with four underwing pylons in addition to the rotary launcher in the fuselage, giving a maximum load of 16 Kh-55s or 14 Kh-55SMs. 56 were built.
Modernized version of MS16 with advanced radio-radar equipment as well as a target-acquiring/navigation system based on GLONASS. Four underwing pylons for up to 8 Kh-101/102 stealth cruise missiles. 19 aircraft have been modernized as of late December 2018. Its combat debut was made on 17 November 2016 in Syria.
Experimental version for air-dropping an RS ramjet powered aircraft.
Variant of the basic Bear-A configuration, redesigned for maritime reconnaissance and targeting as well as electronic intelligence for service in the Soviet Naval Aviation. Known to NATO as the Bear-D.
Training variant, modified from surviving Bear-As but now all have been retired. Known to NATO as the Bear-T.
Special carrier aircraft to test-drop the largest thermonuclear weapon ever designed, the Tsar Bomba.
Long-range intercontinental high-altitude strategic bomber prototype, designed to climb up to 16,000-17,000 m. It was a high-altitude version of the Tupolev Tu-95 aircraft with high-altitude augmented turboprop TV-16 engines and with a new, enlarged-area wing. Plant tests of the aircraft were performed with non-high altitude TV-12 engines in 1955–1956.