Home' Asia Pacific Defence Reporter : APDR February 2016 Contents 36 Asia Pacific Defence Reporter FEB 2016
thrust for the ordinary AL-31F. Other improvements
have been TBO extension to 1,500 hours and lifetime
to 4,000 hours. A thrust-vectoring nozzle is also part of
the Item 117S design. Flight trials proved Item 117S
to be a design success. Its high thrust-to-weight ratio
was rendered good enough even for a fifth generation
fighter. Thus, the engine was selected for the Sukhoi
T-50, also known as the PAKFA. And went into numeric
production at Ufa MPO and Saturn’s plant in Rybinsk.
Replacing AL-31F by an experimental Item 117S
gave the Su-27M side 710 extra thrust at transonic
regimes. This fact encouraged Sukhoi to research
whether the aircraft can actually stay supersonic at
“military power” setting (maximum non-reheated thrust).
Calculations showed that it could, provided the canards
were removed and the center of gravity shifted to
reduce losses from aerodynamic drag. This was the
justification to resume the program and rework the
Su-35 so as to abolished the earlier “integral triplane
concept” (Su-30MKI, Su-33 and Su-27M) of classic
aerodynamic design to reduce drag at transonic and
RUSSIAN AIR FORCE GOES FOR THE
Sukhoi resumed work on the Su-35 in 2005, focusing
on the accommodation of more modern radar and more
powerful engines. The MAKS’2007 show provided a
convenient platform to exhibit a demonstrator aircraft
statically. It flew for the first time in February 2008.
At first, funding for the program was largely
commercial, provided by leading Russian banks in the
belief that the Su-35 international sales campaign may
win interest from foreign buyers, Venezuela and China
Even though the intended customers liked the aircraft,
they hesitated to play the role of a launch customer.
Subsequently, Sukhoi went back to the Russian defense
ministry. It was more successful this time.
The ministry placed an initial order for 48 aircraft
in 2009, due for delivery in 2012 through 2015. The
version for the Russian air force was given designation
The relaunched Su-35 attracted the Chinese.
They filed a formal application to buy the type in
2011. According to Russian sources, the exportable
Su-35 was offered at $85 million apiece. Preliminary
agreement on the sale was reached the following year,
but contractual work on financial and technical issues
proceeded slowly. Russia suspected that if China
bought only a small quantity it would reverse-engineer
the Su-35 and launch a copy into production locally, as
it did with the Su-27SK. For its part, China requested
that Sukhoi integrate Chinese avionics and mission
equipment onto a customized Chinese version.
The sides managed to find a compromise but not
before the Russian air force accepted 40 aircraft,
including the last four in late October – early November
2015. By the time Singapore Airshow 2016 opens, the
launch order for 48 aircraft is expected to be fulfilled.
In January this year, the Moscow-based Vedomosti
newspaper wrote, referring to unnamed sources in the
industry, that the Russian defense ministry and United
Aircraft Corporation had agreed terms of the follow-on
order for 50 more aircraft worth Rouble 60 billion.
Briefly, the Su-35S differs from other members of the
prolific Sukhoi “Flanker” family in the following ways.
First. Much more powerful radar with considerably
longer detection ranges.
Second. Extended arsenal of PGMs that now includes
long-range radar-guided missiles.
Third. Supercruise capability thanks to more powerful
Item 117S engines.
Fourth. Smarter pilot’s station with a wide-view HUD,
two huge MFDs and new-generation HMS.
Fifth. Modern EW features by way of modern radar
technologies and podded systems.
Sixth. Advanced electro-optics.
Seventh. Various refinements in aerodynamics and
FCS resulting in better maneuvering qualities.
Eighth. Larger inner tanks for longer range.
Ninth. A long lifetime and low maintenance,
comparable with the best designs from the West.
The above are “extra” qualities to the already
recognized merits of the Su-27/30 Flanker family. These
Superb maneuverability through the use of vectored
thrust (Su-30MKI/MKM/SM); admirable payload-range
performance, exceeding that of many competing fighter
designs; ruggedness and maintainability; and proven
service record. Also, many manuals, instructions and
training tools have been prepared and service-proven,
including top-standard procedure and flight simulators,
maintenance and combat planning software.
Like any other product, the Flanker family has some
weak points. Among those are relatively high fuel burn
compared to smaller jets, and the need for higher-grade
aerodromes. Unlike earlier Russian engines, the AL-31F
engine family is sensitive to the quality of fuel and
lubricants. Unlike many second and third generation
Russian fighter designs, the Flanker is, overall, a rather
complex aircraft, requiring regular, skilled maintenance
done by dedicated professionals. Its missiles are
air-launched weapons made in Russia and Ukraine. Use
of NATO standard bombs and missiles is possible only
in theory. A special effort to integrate them could prove
costly but may be successful should all sides involved
According to Sukhoi, the Su-35S is an aviation system
able to fill the role of heavyweight multirole fighter until
fifth-generation aircraft become mature enough and
available in worthwhile numbers. At the same time, the
Su-35S uses some technologies developed for fifth
generation fighters since the late 1980s, when the work
began in Soviet Union (and then in Russia).
Sukhoi often calls the Su-35 “a sort of testbed
to prove some solutions for use in future on the
PAKFA”. As such, the Su-35S has a digital information
management system [IUS] that includes two central
onboard computers. Computing power is provide by
Baget-53-31M central processors.
The Su-35 is advertised as a truly multifunctional
aircraft able to perform both air-to-air and ground attack
missions. Maximum takeoff weight is 38.8 tons. The
aircraft has twelve hard points to carry up to eight tons
of external loads. Also, it retains the GSh-301 single-
barrel 30-mm rapid-fire cannon from the Su-27, with
150 rounds of ammunition.
The Su-35 has a wing with “quasi adaptive” leading
and trailing edges for optimal performance at low
speeds and dogfighting. At the same time, the aircraft
has a limited supercruise capability. It is able to fly
supersonically (M=1.1) on “military power” setting.
The refined design of the fuselage allows for an
almost one-fifth increase in internal fuel capacity. The
figure is now 11,500kg against 9,400kg for the Su-27.
The Su-35 can carry two 1,800-litre drop tanks on
underwing pylons to boost fuel capacity to 14,500kg.
The Su-35S can ferry 3,600 km clean and 4,500
km with fuel tanks. The aircraft is equipped with a
telescopic fuel probe for “probe-basket” aerial refueling.
It can refuel mid-air from an Il-78 tanker at a rate of 1,100
liters per minute.
Shaping the Su-35S, Sukhoi engineers tried to
introduce many improvements so as to eliminate or
reduce negative points discovered during the long
service of the Su-27 family (inducted some thirty
years ago). They also tried to make use of some new
technologies now available and do so in such a way to
not change the well-tried design solutions of the original
Su-27. This would reduce the need for lengthy and
Aerodynamics refinements include redesign of air
intakes for higher flow and less drag. The aircraft used
to have a large air brake on the upper fuselage. Its
function is now carried out by differential [inwards]
deflection of the rudders. A larger and heavier forward
fuselage section created the need for a stronger nose
gear strut and the use of two wheels instead of one on
the early Flankers.
The pilot’s station is designed to a HOTAS concept.
It features two large LCDs each measuring 9x12 inches,
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