The Sukhoi Su-35 is a single-seat, twin-engined supermaneuverability multirole fighter. It is a derivative of the Su-27 'Flanker', and was initially known as the Su-27M. More than a dozen of these were built with some used by the Russian Knights aerobatic demonstration team. The Su-35 had been offered to many countries, including India, Brazil and South Korea.
In the 1980s, Sukhoi was looking to upgrade its high-performance Su-27. The resultant Su-35 embodies aerodynamic refinements to give it more manoeuvrability, greatly enhanced avionics, longer range, and a more powerful engine. The first prototype, converted from a production Su-27, made its maiden flight in June 1988. The Su-35 was further developed into the Su-37, which has thrust-vectoring capabilities, and the Su-35BM, classed as 4++ generation fighter by its manufacturer. The new model entered into serial production as the Su-35S for the Russian Air Force in 2010.
Upgraded Su-27
In the early 1980s, as the Su-27 was entering service with the Soviet Air Force, Sukhoi was looking to develop a follow on variant. This variant, originally designated the "Su-27M", would be much more agile and feature greatly improved avionics than the aircraft considered to be the best contemporary fighter. It was also to carry more armament to improve its capacity as an air-to-ground platform.
Known within the design bureau as the "T10-M", development began in the early 1980s. The improved variant featured a host of changes regarding aerodynamic refinements, avionics and propulsion upgrades, construction methods, as well as increased payload carriage. High-strength composites and aluminium-lithium were used not only to reduce weight, but to boost internal fuel volume. Distinguishing features are the canards, which improve airflow over the wings, eliminating buffeting and allowing the aircraft to fly at a very high angle of attack of 120°, i.e., past the vertical. The canards are governed by a new digital fly-by-wire flight control system. It is outfitted with the Luylka Al-31FM engine, also found on the Su-34 tactical bomber. This powerplant is larger, more reliable, and with a thrust of 28,218 lbf (125.52 kN) is more powerful.
Also new was the fire-control system, at the heart of which is the more powerful N-011 Zhuk-27 pulse-Doppler radar. The radar can track 15 aerial targets simultaneously and guide six missiles towards them. To exploit the improved radar, two additional underwing pylons were added. In the aircraft "stinger" is the Phazotron N-012 rear-ward facing radar, which effectively provides the aircraft impunity from attacks from behind. The aircraft can carry a variety of bombs and both air-to-air and air-to-surface missiles. Among the weapons it can carry include the R-27, R-73, R-77, Kh-29, Kh-59, Kh-31, KAB-500 and KAB-1500, along with napalm, dumb and cluster bombs. The cockpit was modernised, equipped with multi-function colour LCD screens, and the pilot sits on the K-36DM ejection seat inclined at 30° to improve g-force tolerance. Range is increased to 4,000 km (2,222 nmi) through additional fuel capacity; with the fitting of an aerial refuelling probe, range can be further extended. The aircraft is characterized by its twin nose wheel – as a result of higher payload – and larger tail fins with horizontal carbon fibre square-topped tips.
Testing
The Su-27M (T-10S-70) prototype first flew on 28 June 1988 at the hands of Sukhoi Chief Test Pilot Oleg Tsoi. The first prototype differed slightly from later examples in: retaining standard Su-27 vertical stabilizers without the cropped top; lacking a fire-control system; having an unusual three-tone grey/blue camouflage scheme, along with minor differences. Designated T10M-1 to T10M-10, the first 10 prototypes were built by KnAAPO in conjunction with Sukhoi, as the Soviet aerospace system was different from Western structure. They slightly differed from another. Four were converted Su-27s and the others being new-builds. The second prototype started flight testing in January 1989, while the third followed in mid-1992. The prototypes were used to validate the new flight-control system and canard fore-planes.
In 1990, the first prototype was displayed to senior Ministry of Defence officials at Kubinka Air Base. The aircraft's first flying demonstration came on 13 February 1992, before the leaders of the CIS republics at Machulishi, Minsk. Later in the year it made its public debut at the Farnborough Airshow. The third prototype, T10M-3, appeared at the Dubai Airshow in 1993, by which time Sukhoi had re-designated its fighter the Su-35. T10M-3 performed an aerobatic display, demonstrating its dogfighting capabilities and tricks, including the Pugachev's Cobra, to potential export customers. Viktor Pugachyov subsequently piloted the prototype in a mock fight with an Su-30MK. The Su-35 performed at numerous air shows during the following years, including the 1993 and 1995 MAKS Airshows and the 1994 ILA. In addition to Su-27 conversions, three production Su-35s were completed in 1996 and delivered to Russian Air Force (VVS) for testing.
During the flight test programme of the Su-35, the aircraft performed manoeuvres such as the Pugachev's Cobra and tailslide. It was discovered that active controls during these performances could not be achieved. The 11th prototype Su-27M, T10M-11, was built by KnAAPO and delivered in 1995 for the installation of exclusive systems and equipments. The resultant aircraft was re-designated Su-37. With thrust vectoring capabilities, it made its first flight in April 1996. A second Su-35 was modified into a Su-37 in the late 1990s.
In total, 15 flight-capable Su-35 (Su-27M) aircraft were produced, including a Su-35UB two-seat prototype. The original Su-35 never entered serial production due to a lack of funding, and the Russian Air Force continued to use its Su-27 fleet. The Su-35's automatic control of canards and the Su-37's thrust-vectoring engine nozzles with some changes were applied to the Sukhoi Su-30MKI.
Further development
From the mid-2000s, Sukhoi and its KnAAPO division further developed the Su-35 concept and improved it with additional cutting-edge technologies eyeing potential foreign sales, marketing it as Su-35BM (Bolshaya Modernizatsiya, or "Big Modernization"). The experiences of 2008 South Ossetia war has also opened its prospects to replace ageing Su-27 fighters in the Russian Air Force's fleet. The modernized Su-35 will serve as an interim design until the fifth generation Sukhoi PAK FA fighter enters service. The modernized Su-35 is considered to be 4++ generation by Sukhoi.
The modernized Su-35 was presented at the 2007 MAKS Airshow. The new features of the aircraft include a reinforced airframe with a more extensive use of titanium alloys, thus increasing the airframes durability to some 30 years or 6,000 service hours, a reduced radar signature from the front, and an improved passive electronically scanned array radar. It is now capable of supercruise. The aircraft featured many other upgrades to its avionics and electronic systems, including digital fly-by-wire and a rear-looking radar for firing semi-active radar homing missiles. The new Su-35 omits the canard and speedbrake; to maintain manoeuvrability equal to or greater than canard-equipped fighters, the Su-35 uses the new 117S engine with fully rotating vectoring thrust nozzles.
The new Su-35 version first flew on 19 February 2008. On 14 April 2009, a Su-35BM prototype crashed during a high-speed ground test. The test pilot escaped unharmed. According to Sukhoi, the fighter's brakes failed during landing, resulting in the speeding aircraft going off the runway and the left engine catching fire. On 18 August of the same year, the Russian Defense Ministry announced a contract for 48 Su-35S (Serial) fighters along with 16 Su-27/30 fighters to be delivered by 2015. Sberbank agreed, in September 2010, to provide funding for the Su-35 program. In November 2009, Sukhoi started manufacturing on the first serial aircraft. On 14 October 2010, Sukhoi announced that the first production Su-35S had completed general assembly and that the first aircraft would be delivered to the Russian Ministry of Defense by the end of the year. In May 2011, the first production model Su-35S was flown for the first time. In 2009, Sukhoi estimated that the Su-35 would be manufactured at a rate of 24 to 30 aircraft each year from 2010 to 2020.
General characteristics
- Crew: 1
- Length: 21.9 m (72.9 ft)
- Wingspan: 15.3 m (50.2 ft)
- Height: 5.90 m (19.4 ft)
- Wing area: 62.0 m² (667 ft²)
- Empty weight: 18,400 kg (40,570 lb)
- Loaded weight: 25,300 kg (56,660 lb)
- Max takeoff weight: 34,500 kg (76,060 lb)
- Powerplant: 2 × Saturn 117S with TVC nozzle turbofan
- Dry thrust: 8,800 kgf (86.3 kN, 19,400 lbf) each
- Thrust with afterburner: 14,500 kgf (142 kN, 31,900 lbf) each
Performance
- Maximum speed: Mach 2.25 (2,390 km/h, 1,490 mph) at altitude
- Range: 3,600 km (1,940 nmi) ; (1,580 km, 850 nmi near ground level)
- Ferry range: 4,500 km (2,430 nmi) with external fuel tanks
- Service ceiling: 18,000 m (59,100 ft)
- Rate of climb: >280 m/s (>55,100 ft/min)
- Wing loading: 408 kg/m² (84.9 lb/ft²)
- Thrust/weight: 1.1
Armament
- 1 × 30 mm GSh-30 internal cannon with 150 rounds
- 2 × wingtip rails for R-73 air-to-air missiles or ECM pods
- 12 × wing and fuselage stations for up to 8,000 kg (17,630 lb) of ordnance, including a variety of air-to-air missiles, air-to-surface missiles, rockets, and bombs such as:
- Vympel R-27: R-27R, R-27ER, R-27T, R-27ET, R-27EP, R-27AE
- Vympel R-77: R-77, and the proposed R-77M1, R-77T
- Vympel R-73: R-73E, R-73M, R-74M
- Kh-31: Kh-31A, Kh-31P Anti-Radiation Missile
- Kh-59
- Kh-29: Kh-29T, Kh-29L
- KAB-500L laser-guided bomb
- KAB-1500 laser-guided bomb
- LGB-250 laser-guided bomb
- FAB-250 250 kilograms (550 lb) unguided bombs
- FAB-500 500 kilograms (1,100 lb) unguided bombs
- S-25LD laser-guided rocket, S-250 unguided rocket
- B-8 unguided S-8 rocket pods
- B-13 unguided S-13 rocket pods
Avionics
- Irbis-E passive phased array radar
