All posts by Lucy

For Sale: America’s Lethal Nuclear-Powered Submarines?

Manufacturer

General Dynamics Electric Boat Division and Huntington Ingalls Industries Inc. – Newport News Shipbuilding.
Service

USN
Armament

Tomahawk missiles, twelve VLS tubes, MK48 ADCAP torpedoes, four torpedo tubes
Propulsion

One nuclear reactor, one shaft
Speed

25+ knots
Crew

15 officers; 117 enlisted

Forget the J-20, F-22 and F-35, this is a real Super Maneuverable Fighter

Forget the J-20, F-22 and F-35, this is a real Super Maneuverable Fighter

The Sukhoi Su-35 (Russian: Сухой Су-35; NATO reporting name: Flanker-E[N 1]) is a designation for two separate, heavily upgraded derivatives of the Su-27 aircraft. They are single-seat, twin-engine, supermaneuverable multirole fighters, designed by Sukhoi and built by Komsomolsk-on-Amur Aircraft Production Association (KnAAPO).

The first variant was designed during the 1980s, when Sukhoi sought to upgrade its high-performance Su-27, and was initially known as the Su-27M. Later re-designated Su-35, this derivative incorporated aerodynamic refinements with increased manoeuvrability, enhanced avionics, longer range, and more powerful engines. The first Su-35 prototype, converted from a Su-27, made its maiden flight in June 1988. More than a dozen of these were built, some of which were used by the Russian Knights aerobatic demonstration team. The first Su-35 design was later modified into the Su-37, which possessed thrust vectoring engines and was used as a technology demonstrator. A sole Su-35UB two-seat trainer was built in the late 1990s that strongly resembled the Su-30MK family.

In 2003, Sukhoi embarked on a second modernization of the Su-27 to serve as an interim aircraft awaiting the upcoming Sukhoi PAK FA. This derivative, while omitting the canards and air brake, incorporates a reinforced airframe, improved avionics and radar and thrust-vectoring engines. In 2008 the revamped variant, erroneously named the Su-35BM in the media, began its flight test programme that would involve four prototypes, one of which was lost in 2009.

The Russian Air Force has ordered 98 production units, designated Su-35S, of the newly revamped Su-35. Both Su-35 models were marketed to many countries, including Brazil, China, India, Indonesia, and South Korea; only China has so far ordered the Su-35, placing an order for 24 in late 2015. Indonesia expressed an intent to buy between 8-10 Su-35s in 2015, but has yet to sign a final purchase contract. Other countries have since either purchased other aircraft or lost interest in the Su-35. Sukhoi originally projected that it would export more than 160 units of the second modernized Su-35 worldwide, but sales of the Su-35 have been blunted by updated versions of the Sukhoi Su-30.

Redesigned Su-27

The first aircraft design to receive the Su-35 designation had its origins in the early-1980s. At the time, the Su-27 was entering service with the Soviet armed forces in its definitive production version, which has the internal company designation of T-10S. Having entered production with KnAAPO in 1983, this Su-27 version the following year reached operational readiness with the Soviet Air Defence Forces.[7] The preliminary design effort of what would later be called Su-27M (which is known internally as the T-10M) started in 1982 at the direction of Nikolay Nikitin, who would lead the programme during much of its existence.[8] In December 1983, the Soviet Council of Ministers directed Sukhoi to use the Su-27 as a basis for the development of a multi-role fighter.

A distinguishing feature of the Su-27M design is the addition of canards, which are small lifting surfaces, ahead of the wings. First tested in 1985 using an experimental aircraft, the canards, in complement with the fly-by-wire flight-control system, were the primary reason for the aircraft’s manoeuvrability. The canards and the reshaped leading-edge extension redirect the airflow in such a way so as to eliminate buffeting, which reduces the stress on the airframe and allows it to sustain 10-g manoeuvres without the need for additional structural reinforcement. When working with the flight-control system, the aerodynamic layout allows the aircraft to briefly fly with its nose past the vertical. As such, the pilot could theoretically during combat pitch the Su-27M up 120 degrees in under two seconds and fire missiles at the target. Other notable visible changes compared to the T-10S design included taller vertical tails, provisions for in-flight refuelling and the use of two-wheel nose undercarriage to support the heavier airframe.

Besides the increase in manoeuvrability, another feature that distinguishes the Su-27M from the original design is the new weapons-control system. The centrepiece of this system is the multi-function N011 Bars pulse-Doppler radar, which is capable of detecting targets below the horizon. First installed on the third prototype, the radar transformed the Su-27M from simply being an air defence aircraft into a multi-role fighter capable of attacking ground targets. Compared to the N001 radar of the Su-27, which could only engage one target at a time, the new radar could track fifteen targets and direct missiles towards six of them simultaneously. It was the N011 radar meant that made the front of the aircraft more heavy, which in turn necessitated the addition of the canards; engineers would only later discover the aerodynamic advantages of these devices. Other changes to the aircraft included the use of marginally-uprated turbofan engines, as well as the increased use of lightweight composites and aluminium-lithium alloys in the aircraft’s structure.
Testing and demonstration

Whereas Sukhoi was responsible for the design of the Su-27M, the actual production of the aircraft was carried out by Komsomolsk-on-Amur Aircraft Production Association (KnAAPO), who built fifteen aircraft until 1995. Of the first twelve development aircraft, several of them (including the first) were prototypes converted from T-10S airframes, and so lacked many of the physical alterations of the new design. The first prototype (designated T10M-1) made its first flight after conversion on 28 June 1988, piloted by Oleg Tsoi, followed by the second prototype in January 1989. The third aircraft (T10M-3), which was the first new-built Su-27M, made its first flight in April 1992. By then, the Soviet Union had disintegrated, and the the ensuing economic crisis in Russia throughout the 1990s meant that the original plan to mass produce the aircraft between 1996 and 2005 was abandoned, with the aircraft to serve as experimental testbeds to validate the canards, the flight-control system and, most notably, thrust-vectoring technology. In addition to the twelve development aircraft, three production-standard Su-27Ms were completed and delivered to the Russian Air Force for weapons testing.

By the time of the disintegration of the Soviet Union, Sukhoi had been demonstrating the Su-27M to senior defence and government officials. With its debut to a Western audience at the 1992 Farnborough Airshow, the company redesignated the aircraft as Su-35. The aircraft would subsequently make flying demonstrations overseas in an effort to attract export orders, starting in 1993 with Dubai, where Viktor Pugachev flew it in a mock aerial engagement with an Su-30MK in front of spectators. The aircraft thereafter flew in Berlin and Paris, and would be a regular feature at Russia’s MAKS Air Show. The Russian government cleared the aircraft for export during Sukhoi’s unsuccessful sales campaign in South Korea during the late 1990s and early 2000s.

As the flight test programme of the Su-27M proceeded, engineers discovered that the pilot was not able to maintain active control of the aircraft during certain manoeuvres, such as the Pugachev’s Cobra. The eleventh Su-27M (T10M-11) was therefore installed with thrust-vectoring engine nozzles in 1995, and the resultant Su-37 technology demonstrator made its first flight in April 1996. Its ability to maintain a high angle of attack while flying at close to zero airspeed attracted considerable public attention. The Su-37 also tested the updated N011M radar, as did the twelfth developmental Su-27M aircraft. It later received different engines and updated fly-by-wire controls and cockpit systems for evaluation.

Apart from the single-seat design, a two-seat aircraft was also constructed. Working in cooperation with Sukhoi, KnAAPO’s own engineers designed the Su-35UB so as to combine thrust-vectoring engines with features of the Su-27M. Modified from an Su-30MKK airframe, the aircraft made its first flight in August 2000, and afterwards served as an avionics testbed.[28] While the original Su-35 never entered serial production due to a lack of funding, Sukhoi refined the Su-35’s use of canards and the Su-37’s thrust-vectoring technology and later applied them to the Sukhoi Su-30MKI.[30] One of the Su-35s, T10M-10, served as a testbed for the Saturn 117 engine intended for the PAK FA jet fighter.
Modernization

With the need to update Russia’s ageing fleet of Su-27 aircraft, Sukhoi in the early 2000s converted existing air force aircraft to include a glass cockpit and an improved weapons-control system to accommodate a larger variety of weapon. The Su-27SM, as the modified aircraft is called, made its first flight in December 2002. The success of this project led Sukhoi to announce in December 2003 a follow-up programme, known internally as T-10BM, aimed at a more thorough redesign of the airframe to narrow the qualitative gap between Russian aircraft and foreign so-called fourth-generation aircraft. The resultant aircraft, which is marketed as Su-35, would serve as an interim solution pending the introduction of the Sukhoi PAK FA fifth-generation fighter, many features of which the aircraft would incorporate. Additionally, the aircraft was to be an alternative to the Su-30 family on the export market.

In many respects, the T-10BM design outwardly resembles the Su-27 more than the Su-27M. During tests of the thrust-vectoring engines and the Su-27Ms aerodynamic layout, Sukhoi had assessed that the loss of manoeuvrability due to the removal of the canards – which imposed a weight penalty on the airframe – could be compensated for by the addition of thrust-vectoring nozzles. Industry progress in the fields of avionics and radars have also meant that engineers have reduced the weight and size of such components, which shifted the centre of gravity of an aircraft rearward. Therefore, designers removed the canards (as well as the taller vertical fins and dorsal airbrake) found on the Su-27M. At the same time, the increased use of aluminium and titanium alloys and composites meant that the reinforced airframe, which is similar in empty weight to the Su-27, has a higher maximum take-off weight than that of the Su-27M.

Su-35S avionics: head-up display, 2 big displays, aircraft control stick and throttle control knobs

While the Su-27M design had the avionics and sensors to give the aircraft the nominal designation as a multirole fighter, flight tests with the Russian Air Force revealed difficulties in efficiently deploying the aircraft’s armament. Air force pilots described weapons trials with the aircraft in Akhtubinsk and Lipetsk as a “negative experience”. In particular, there were criticisms of the layout of the cockpit and its adverse impact on the workload of the single pilot. With this crucial lesson, Sukhoi had changed the information management system of the avionics suite on the Su-35. The system now has two digital computers which process information from the flight-control system, the radar and various sensors. The information is then displayed on two 9×12 in. multi-function liquid crystal displays,[39] which replaced the three smaller multi-function cathode-ray tube displays found on the Su-27M. The pilot can also view critical flight information on the head-up display, and is equipped with HOTAS (Hands On Throttle-And-Stick) controls.

The Su-35 employs the powerful N035 Irbis-E passive electronically-scanned array radar, which entered development at the same time as the aircraft and constitutes the core of the Su-35’s weapons-control system. It is capable of detecting an aerial target up to 400 km (250 mi) away, and can track thirty airborne targets and engage eight of them simultaneously; in addition, the multi-function radar is capable of mapping the ground using synthetic aperture mode.[41] Engineers had also installed an OLS-35 optoelectronic targeting system ahead of the cockpit to provide other forms of tracking including infra-red search and track.[41] In addition to the multitude of air-to-ground weaponry, the multi-role Su-35 can deploy air-to-air missiles of up to 300-kilometre (190 mi) range, and can carry the heavy Oniks anti-ship cruise missile.
Thrust vectoring nozzles on a Sukhoi Su-35S

The Su-35 is powered by a pair of Saturn izdeliye (Article) 117S (AL-41F1S) turbofan engines. While based on the AL-31F engine of the Su-27M, it shares the more-powerful core design of PAK FA’s Saturn 117 (AL-41F1). The aircraft is equipped with thrust-vectoring nozzles, which has their rotational axes canted at an angle, similar to the configuration on the Su-30MKI. The nozzles operate in one plane for pitch, but the canting allows the aircraft to produce both roll and yaw by vectoring each engine nozzle differently. A similar thrust vectoring system is also implemented on the PAK FA.[46] Radar-absorbent material is applied to the engine inlets and the front stages of the engine compressor to halve the Su-35’s frontal radar cross-section; the canopy was also modified to deflect radar waves.

The engine reportedly gives the Su-35 the ability to sustain supersonic speed without the use of afterburners. According to Dr. Carlo Kopp of the think tank Air Power Australia, such a “supercruise” feature allows the Su-35 to engage an opponent at a greater velocity and altitude and increases the range of its long-range missiles up to 30–40 percent. He cites the aircraft’s mature airframe and carefully-balanced combination of advanced technology as allowing the Su-35 to achieve a favourable exchange rate against the F-35 radar-evading fighter. A RAND Corporation report in 2008 found that the Su-35 could shoot down 2.4 F-35s for every aircraft lost; however, the US Department of Defense and Lockheed Martin had refuted criticisms of the aircraft, claiming that it is 400 percent more effective in air-to-air combat than any other aircraft other than the F-22.
Production and flight testing

Design work on the Su-35 had been completed by 2007, paving the way for KnAAPO to construct the first prototype in the summer of 2007. The completed prototype, Su-35-1, was then transferred to the Gromov Flight Research Institute in Zhukovsky Airfield, where preparations were made to prepare the aircraft for its first flight. On 19 February, Sergey Bogdan took the aircraft aloft for its first flight from Zhukovsky, accompanied by an Su-30MK2 acting as a chase plane.[51][53] During the 55-minute flight, the pilot took the Su-35 to a height of 5,000 metres (16,000 ft) while carrying out tests on the aircraft’s stability, controllability and engines.[51] Bogdan would later pilot the second prototype on its maiden flight on 2 October from KnAAPO’s Dzemgi Airport.[54] The flight test programme was initially to involve three flying prototypes, but on 26 April 2009, a day before its scheduled maiden flight, the fourth Su-35 (there’s a static test aircraft) crashed during a taxi run at Dzemgi Airport. The aircraft struck a barrier at the end of the runway and was destroyed by fire; the pilot ejected and sustained burn injuries. A commission was opened to investigate the crash, but several sources initially speculated that the incident had been the result of a brake failure or a faulty fuel pump.
The second prototype of the modernized Su-35 (Bort 902) at the 2009 MAKS Airshow, where the Russian Defence Ministry placed the launch order for the aircraft

During the 2009 MAKS air show, the Russian Defence Ministry signed a US$2.5 billion contract for 64 fighters, which consisted of a launch order for 48 Su-35S aircraft. In addition to the order, the Russian government and its development bank Vnesheconombank also agreed to provide Sukhoi with capital for the production programme. In November that year, KnAAPO started manufacturing the first production aircraft,[60] the general assembly of which was completed in October 2010; by then, pilots and engineers had successfully completed preliminary tests of the aircraft’s systems. The first Su-35S took its maiden flight in May 2011, and would be delivered (along with other aircraft) to Akhtubinsk to start state acceptance tests with the Defence Ministry to prepare the aircraft for service. Because production of the Su-35S occurred alongside trials, some early-production aircraft were later modified as a result of such tests.

In March 2015, it was reported that Russia and India signed an agreement to jointly develop a fifth-generation upgrade to the Su-35. A Russian industry source stated that the upgraded Su-35S will cost about US$85 million each.

A contract for another 50 Su-35s was signed in August 2015, but parent company United Aircraft Corporation (UAC) stated in January 2016 that delays in finalizing the order was due to a lack of clarity in Russia’s 2016 federal budget, which was only signed by Russian President Vladimir Putin in mid-December 2015. The fighters will be delivered at a rate of 10 aircraft per year starting in 2016.

Operational history

Russia

Three production Su-27Ms were completed and delivered to VVS in 1996 for testing. They were operated by 929th State Flight Test Center (GLITS in Russian nomenclature) at Vladimirovka air base, Akhtubinsk, performing weapons trials. During one such flights, a weapon pylon, to which a bomb and rocket were attached, fell into a village in Ryazan; nobody was hurt. In 2001, the Air Force decided that the aerobatics team Russian Knights would receive several Su-27Ms, presumably from GLITS and Sukhoi. After pilots from the team undertook conversion course at Vladimirovka, the first of five aircraft was delivered to the team in July 2003. Due to various reasons, they were used as a source of spare parts for other aircraft in the demonstration fleet.

In late May 2011, Sukhoi delivered the first Su-35S to Akhtubinsk to conduct state joint tests to prepare the aircraft for operational service with the VVS. Before the start of the tests, the aircraft’s Su-35’s avionics and integrated defence systems were reportedly not up to the standard of American aircraft. The first of two stages of the trials commenced in August 2011 with the two Su-35 prototypes, which were later joined by four production aircraft. By March 2012, air force pilots flying the six aircraft were conducting tests of the type’s technical characteristics, which were assessed to have complied with requirements by the end of that year. Of the batch of six production aircraft that were handed over in December 2012, five flew to the Gromov Flight Research Institute where the aircraft would, in February 2013, start the eighteen-month second stage of the trials that would focus on the Su-35’s weapons and manoeuvrability in combat.

Twelve Su-35S fighters were delivered to the VVS in December 2013, followed by another twelve aircraft in February 2014, to be deployed with an air regiment based in Russia’s Far East. By then, 34 of the 48 aircraft originally ordered had been delivered with the remaining 14 due in 2015. The introduction of the Su-35 into service with the Russian Air Force is part of a wider service-wide rearmament programme that was started after 2008. Indeed, the 2009 order for 64 aircraft was the most significant contract that the service had signed at the time. The Su-35 would enter service alongside the heavier Su-34 fighter-bomber, as well as the single-seat Su-27SM and two-seat Su-30M2, the latter of which is used to train pilots for the Su-35.

In December 2012, Russian officials commented that the Swifts and Russian Knights aerobatics teams would receive new aircraft to replace the Mikoyan MiG-29 and Su-27, respectively. The Swifts was expected to receive the Su-30SM and the Russian Knights receive the Su-35. However, the Russian Knights’ Su-27 would eventually be replaced by the Su-30SM.

In January 2016, Russia, for the first time in combat conditions, deployed four Su-35S planes to its Khmeimim air base; on 1 February the Russian Defence Ministry said the aircraft had begun to participate in the Russian air operations in Syria.

China

Since the early 1990s, an extensive sales arrangement of the Su-35 to China has been discussed. Sukhoi officials, in 1995, announced their proposal to co-produce the Su-35 with China, contingent on Beijing’s agreement to purchase 120 aircraft.[82] However, it was alleged that the Russian Foreign Ministry blocked the sale of the Su-35 and Tupolev Tu-22M bombers over concerns about the arrangements for Chinese production of the Su-27.

In 2006, China was showing interest in the modernized Su-35, and was negotiating with Moscow for a purchase of the fighter. At the 2007 MAKS air show, a number of Chinese delegates were seen taking photos and videos of the Su-35 prototypes. In November 2010, Russia, through Rosoboronexport, was ready to resume talks with China on the sale of the Su-35. China reciprocated in 2011 by presenting a proposal on the purchase of the fighter.

In March 2012, the Russian media reported that the two countries were in final contract negotiations for 48 Su-35s; the remaining obstacle is reportedly Moscow’s demand that Beijing guarantee proper licensing for its Su-35 production. China denied this deal because it did not want the Su-35, but only shown slight interest in its 117S engine; at the 2012 Zhuhai Air Show Russia approached China with its 117S engine in a failed attempt to sell Su-35.

In late 2012, it was reported that China wanted to purchase only 24 units, which was less than what Russia deemed to be worthwhile, thus stalling negotiations. By late 2012, the negotiations resumed, this time involving 24 aircraft. During the next three years, negotiations would prove to be protracted, with several false reports claiming that a deal had been reached between the two countries; for example, in March 2013, it was reported that both sides had signed an initial agreement for 24 Su-35s and four submarines prior to Chinese President Xi Jinping’s visit to Russia.[94][95][96] Negotiations concluded in November 2015, when a contract for 24 fighters worth $2 billion, was signed. The first aircraft will be delivered to China in 2016. One motive for China’s purchase of the Su-35 is its thrust-vectoring 117S engine; while China has recently developed modern fighters, its engines still lag behind Russia and the West despite heavy investments by China in domestic engine programs during recent years to catch up. The desire to obtain advanced jet engines through the acquisition of the Su-35 is evidenced by the aircraft’s marginally better performance in maneuverability, range, and payload compared to domestic fighters like the J-11D while having a less sophisticated PESA radar. According to Russian National Defense magazine, China will not order additional Su-35s but will instead focus on its domestic fighter programs especially its fifth generation fighters.

Indonesia

Also in September 2015, Indonesia’s Ministry of Defence selected the Su-35 to replace the Indonesian Air Force’s aging F-5E Tiger II fleet.[103][104] The Su-35 competed with several western fighters including Eurofighter Typhoon, Dassault Rafale, F-16V Viper, and Saab JAS 39 Gripen. As of November 2016, Indonesia were in negotiations with Russia for the purchase of nine or ten aircraft.[105] No contract had been signed by March 2017, although Rostec’s Director of International Cooperation and Regional Policy, Viktor Kladov stated that “… the contract for Su-35 … will be signed in the upcoming months”.

On 6 June 2017, Russia and Indonesia announced the contract for an unknown number of Su-35 aircraft was finalized and that it was to be signed later that year. On 12 June 2017, Defense Minister confirmed that Indonesia will buy 10 Su-35s, and Russia’s Sukhoi will open a factory for spare parts as with the contract.
Others

In May 2006, it was reported that Venezuela planned to purchase dozens of Su-30 and Su-35 fighters, and as many as 100 T-90 tanks. There were unconfirmed reports in October 2008 that the Venezuela government had ordered 24 Su-35s for the Venezuelan Air Force. In July 2012, Venezuelan President Hugo Chávez repeated his interest in acquiring the Su-35 fighters.

In January 2015, North Korea has expressed interest in the fighter. But due to the international sanctions imposed on North Korea the delivery of fighters is unlikely in the near future.[

Vietnam and Algeria are also interested in this aircraft. In February 2015, a Su-35 was tested at Tamanrasset Airport in Algeria. According to Kommersant, the Algerian military were satisfied with the fighter’s flight characteristics and now Moscow is waiting for a formal application. It is expected that the first phase will focus on the acquisition of at least 12 aircraft. Egypt and Pakistan had also expressed interest in ordering the Su-35. A Russian official stated the nation was not in talks with Pakistan about the Su-35.[120]

In February 2017, the United Arab Emirates has agreed to purchase a batch of advanced Sukhoi Su-35 fighters from Russia, according to Sergei Chemezov, Chief of Rostec. No other details given about how many Su-35s the UAE has ordered or when the aircraft would be delivered. The UAE also recently signed an agreement to co-develop a new fifth-generation fighter with Russia.

Brazil

In 2001, Brazil under President Fernando Henrique Cardoso announced the F-X tender to procure a replacement for its aging aircraft including the Dassault Mirage IIID/E and Northrop F-5. Sukhoi partnered with Avibras to submit the Su-27M for the US$700 million tender that would see at least twelve aircraft delivered to the Brazilian Air Force. Other contenders were the Mirage 2000, F-16, MiG-29, and JAS Gripen. Any contract would have been accompanied by an offset agreement that would see the winning bidder provide input to Brazil’s aviation industry. Had the Su-35 won, Russia would have purchased 50 Embraer airliners for use by Aeroflot. The Su-35 and Mirage 2000 were the front-runners to the program, but the former was favoured for its superior flight characteristics. According to the Centre for Analysis of Strategies and Technologies, the Su-35 would have been the first heavy supersonic fighter to be delivered to Latin America. The tender was suspended for much of 2003 as the newly elected President Luiz Inácio Lula da Silva focused more on social welfare. The tender was again suspended in 2005, pending the availability of new fighters.

In 2007, Russia submitted the modernized Su-35 for Brazil’s relaunched F-X2 competition. The tender this time attracted the participation of the Boeing F/A-18E/F Super Hornet, Lockheed Martin F-16BR, Saab JAS Gripen NG, Dassault Rafale, and Eurofighter Typhoon. Brazil was looking to purchase at least 36, and up to 120, aircraft to replace Northrop F-5BRs, Alenia/Embraer A-1Ms, and Dassault Mirage IIIs. In October 2008, the Brazilian Air Force selected the Boeing F/A-18E/F Super Hornet, Dassault Rafale, and Saab Gripen NG as the three finalists.[131] In October 2009, Rosoboronexport declared that Russia would provide 120 Su-35s and full technology transfer to Brazil. The Su-35 was expected re-enter the tender after Brazilian President Dilma Rousseff postponed the programme in January 2011 due to fiscal concerns. In December 2013, the Brazilian government selected the Gripen NG for procurement.

Others

At the 1996 Seoul Air Show, Russia submitted the Su-35 (Su-27M) and Su-37 for South Korea’s F-X procurement programme, a 40-aircraft requirement to replace the Republic of Korea Air Force’s F-4D/Es, RF-4Cs, and F-5E/Fs. The Su-35 competed against the Dassault Rafale, Eurofighter Typhoon, and F-15K Slam Eagle. The proposed Su-35 featured a phased grid radar and AL-31FP vectoring-thrust engines; final assembly would have taken place in South Korea, the offer included a full technology transfer. The US$5 billion contract may have been partially financed through a debt-reduction deal on money Russia owed to South Korea. The Su-35 was reportedly the cheapest aircraft to purchase and maintain, however it was eliminated early in the bidding process, along with the Typhoon. The F-15K, viewed as the competition’s front-runner due to South Korea’s ties with the United States, was chosen in 2002. Reports have claimed that, had South Korea not chosen the F-15K, the United States would have refused to integrate American weapons on the selected aircraft.

In 2002, Sukhoi offered Su-30 family aircraft to Australia, including the Su-35. However Australia opted for the F-35 to replace the F-111 and F/A-18. Russia has offered the Su-35 to India, Malaysia, Algeria and Greece; no firm contracts have materialised, with the first three countries having been occupied with other fighter projects and unlikely to procure the modernized Su-35. In 2010, Libya was expected to sign a contract for twelve Su-35s as part of a bigger military transaction that would have included S-300PMU-2 surface-to-air missiles, Kilo-class submarines, and T-90 tanks. The civil war in Libya and the resulting military intervention caused Rosoboronexport to miss out on US$4 billion in arranged contracts as they were never signed.

Source : wikipedia.org/wiki/Sukhoi_Su-35