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.
Variants
Tu-95/1
The first prototype
powered by Kuznetsov 2TV-2F coupled turboprop engines.
Tu-95/2
The second prototype powered by
Kuznetsov NK-12 turboprops.
Tu-95
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.
Tu-95K
Experimental version for air-dropping a
MiG-19 SM-20 jet aircraft.
Tu-95K22
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.
Tu-95K/Tu-95KD
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.
Tu-95KM
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.
Tu-95LAL
Experimental
nuclear-powered aircraft project.
Tu-95M
Modification of the serial Tu-95 with
the NK-12M engines. 19 were built.
Tu-95M-55
Missile carrier.
Tu-95MR
Bear-A modified
for photo-reconnaissance and produced for Naval Aviation. Known to NATO as the
Bear-E.
Tu-95MS/Tu-95MS6/Tu-95MS16
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.
Tu-95MS6
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.
Tu-95MS16
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.
Tu-95MSM
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.
Tu-95N
Experimental version for air-dropping
an RS ramjet powered aircraft.
Tu-95RT
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.
Tu-95U
Training variant,
modified from surviving Bear-As but now all have been retired. Known to NATO as
the Bear-T.
Tu-95V
Special carrier aircraft to test-drop
the largest thermonuclear weapon ever designed, the Tsar Bomba.
Tu-96
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.
