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Sukhoi PAK FA / T-50 / Su-57





The Sukhoi PAK FA is a twin-engine jet fighter being developed by Sukhoi OKB for the Russian Air Force. The first prototype flew in 2010.







In 1979, the Soviet Union outlined a need for a next-generation aircraft intended to enter service in the 1990s. The project was designated the I-90 (Russian: Истребитель, Istrebitel, "Fighter") and required the fighter to have substantial ground attack capabilities and would eventually replace the MiG-29s and Su-27s in frontline tactical aviation service.
The subsequent programme resulted in Mikoyan's selection to develop the MiG 1.44. The MiG 1.44 was subsequently cancelled and a new programme for a next-generation fighter, PAK FA, was initiated. In 2002, Sukhoi was selected over Mikoyan as the winner of the PAK FA competition and would lead the design of the new aircraft.
To reduce the PAK FA's developmental risk and spread out associated costs, as well as to bridge the gap between it and older previous generation fighters, some of its technology and features, such as propulsion and avionics, were implemented in the Sukhoi Su-35S fighter, an advanced variant of the Su-27. The Novosibirsk Aircraft Production Association (NAPO) is manufacturing the new multi-role fighter at Komsomol'sk-on-Amur along with Komsomolsk-on-Amur Aircraft Production Association (KnAAPO), and final assembly is to take place at Komsomol'sk-on-Amur.
Following a competition held in 2003, the Tekhnokompleks Scientific and Production Center, Ramenskoye Instrument Building Design Bureau, the Tikhomirov Scientific Research Institute of Instrument Design (NIIP), the Ural Optical and Mechanical Plant (UOMZ) in Yekaterinburg, the Polet firm in Nizhny Novgorod and the Central Scientific Research Radio Engineering Institute in Moscow were selected for the development of the PAK-FA's avionics suite. NPO Saturn is the lead contractor for the interim engines; Saturn and MMPP Salyut were to compete for the definitive second stage engines.
The Su-57 has a blended wing body fuselage and incorporates all-moving horizontal and vertical stabilizers; the vertical stabilizers toe inwards to serve as the aircraft's airbrake. The aircraft incorporates thrust vectoring and has adjustable leading–edge vortex controllers (LEVCONs) designed to control vortices generated by the leading edge root extensions, and can provide trim and improve high angle of attack behaviour, including a quick stall recovery if the thrust vectoring system fails. The advanced flight control system and thrust vectoring nozzles make the aircraft departure-resistant and highly maneuverable in both pitch and yaw, enabling the aircraft to perform very high angles of attack maneuvers such as the Pugachev's Cobra, along with doing flat rotations with little altitude loss. The aircraft's aerodynamics and engines enable it to achieve Mach 2 and is also capable of flying supersonic flight without afterburners, or supercruise. The Su-57 has a climb rate ranging from 330 m/s (1,100 ft/s) to 361 m/s (1,180 ft/s).
Weapons are housed in two tandem main weapons bays between the engine nacelles and smaller bulged, triangular-section bays near the wing root. Advanced engines and aerodynamics enable the Su-57 to supercruise, sustained supersonic flight without using afterburners. Combined with a high fuel load, the fighter has a supersonic range of over 1,500 km (930 mi), more than twice that of the Su-27. Extendible refueling probe is available to further increase its range. In the Su-57's design, Sukhoi addressed what it considered to be the F-22's limitations, such as its inability to use thrust vectoring to induce roll and yaw moments and a lack of space for weapons bays between the engines, and complications for stall recovery if thrust vectoring fails.
The airframe incorporates planform edge alignment to reduce its radar cross-section (RCS); the leading and trailing edges of the wings and control surfaces and the serrated edges of skin panels are carefully angled to reduce the number of directions the radar waves can be reflected. Weapons are carried internally in weapons bays within the airframe and antennas are recessed from the surface of the skin to preserve the aircraft's stealthy shape. The infrared search-and-track sensor housing is turned backwards when not in use and its rear is treated with radar-absorbent material (RAM) to reduce its radar return. To mask the significant RCS contribution of the engine face, the partial serpentine inlet obscures most of the engine's fan and inlet guide-vanes (IGV). The production aircraft incorporates radar-absorbing materials on the walls of the air ducts and radar blockers in front of the engine fan to hide it from all angles. The fuselage of the aircraft is to also use RAM to absorb radar emissions and reduce the reflection back to the source.
The combined effect of airframe shape and RAM of the production aircraft is estimated to have reduced the aircraft's RCS to a value thirty times smaller than that of the Su-27. Sukhoi's patent for the Su-57's stealth features cites an average RCS of approximately 0.1 to 1 sq.m, compared to the Su-27's of approximately 10 to 15 sq.m. Like other stealth fighters, the Su-57's low observability measures are chiefly effective against high-frequency (between 3 and 30 GHz) radars, usually found on other aircraft. The effects of Rayleigh scattering and resonance mean that low-frequency radars, employed by weather radars and early-warning radars are more likely to detect the Su-57 due to its size. Such radars are also large, susceptible to clutter and are less precise.
Pre-production T-50 and initial production batches of the Su-57 were to use interim engines, a pair of NPO Saturn izdeliye 117, or AL-41F1. Closely related to the Saturn 117S engine used by the Su-35S, the 117 engine is a highly improved and uprated variant of the AL-31 that powers the Su-27 family of aircraft. The 117 engine produces 93.1 kN (21,000 lbf) of dry thrust, 147.1 kN (33,067 lbf) of thrust in afterburner, and has a thrust to weight ratio of 10.5:1. The engines have full authority digital engine control (FADEC) and are integrated into the flight control system to facilitate maneuverability and handling.
The two 117 engines incorporate thrust vectoring (TVC) nozzles whose rotational axes are each canted at an angle, similar to the nozzle arrangement of the Su-35S. This configuration allows the aircraft to produce thrust vectoring moments about all three rotational axes, pitch, yaw and roll. Thrust vectoring nozzles themselves operate in only one plane; the canting allows the aircraft to produce both roll and yaw by vectoring each engine nozzle differently. The engine inlet incorporates variable intake ramps for increased supersonic efficiency and retractable mesh screens to prevent foreign object debris being ingested that would cause engine damage. The 117 engine is to also incorporate infrared and RCS reduction measures. In 2014, the Indian Air Force openly expressed concerns over the reliability and performance of the 117 engines; during the 2011 Moscow Air Show, a T-50 suffered a compressor stall that forced the aircraft to abort takeoff.
The T-50 prototype has two tandem main internal weapon bays each approximately 4.6 m (15.1 ft) long and 1.0 m (3.3 ft) wide and two small triangular-section weapon bays that protrude under the fuselage near the wing root. Vympel was developing two ejection launchers for the main bays: the UVKU-50L for missiles weighing up to 300 kg (660 lb) and the UVKU-50U for ordnance weighing up to 700 kg (1,500 lb).
The main bays can also accommodate air-to-ground missiles as well as multiple 250 kg (550 lb) KAB-250 or 500 kg (1,100 lb) KAB-500 precision guided bombs. For missions that do not require stealth, the Su-57 can carry stores on its six external hardpoints.
The aircraft has an internally mounted 9A1-4071K (GSh-30-1) 30 mm cannon near the right LEVCON root. The cannon has a 50 kg weight, and can fire up to 1,800 rounds per minute. The cannon can fire blast-fragmentation, incendiary and armor-piercing tracer rounds and is effective against even lightly armored ground, sea and aerial target up to 800 m for aerial target and 1,800 m for ground target. The cannon is equipped with autonomous water cooling system, where water inside barrel jacket vaporized during operation.
The aircraft canopy is made of composite material and 70-90 nm thick metal oxide layers with enhanced radar wave absorbing to minimize the radar return of the cockpit by 30% and protect the pilot from the impact of ultraviolet and thermal radiation.
The Su-57 has a glass cockpit with two 38 cm (15 in) main multi-functional LCD displays similar to the arrangement of the Su-35S. Positioned around the cockpit are three smaller control panel displays. The cockpit has a wide-angle (30° by 22°) head-up display (HUD). Primary controls are the joystick and a pair of throttles. The aircraft uses a two-piece canopy, with the aft section sliding forward and locking into place. The canopy is treated with special coatings to increase the aircraft's stealth.
The Su-57 employs the NPP Zvezda K-36D-5 ejection seat and the SOZhE-50 life support system, which comprises the anti-g and oxygen generating system. The 30 kg (66 lb) oxygen generating system will provide the pilot with unlimited oxygen supply. The life support system will enable pilots to perform 9-g maneuvers for up to 30 seconds at a time, and the new VKK-17 partial pressure suit will allow safe ejection at altitudes of up to 23,000 m (75,000 ft). In November 2018, the system is said to be at the final stage of test -the stage of state flight tests- and the test pilots are already flying in this equipment. The pilot gear also consisted of a digital helmet which connected to on-board photo and video cameras to improve pilot's situational awareness. It also features pupil's movement detection system to allow automatic targeting unlike previous Soviet fighters. There also a survival kit consisting a pan, antenna, signal mirror, 16 cubes of sugar, first aid kit, two match boxes, a signal pistol with charges, 1.5-liter bottle of water, machete knife, radio beacon, and portable radio. The pilot could use the survival kit's container as a boat or water-proof sleeping bag if necessary.
The main avionics systems are the Sh121 multifunctional integrated radio electronic system (MIRES) and the 101KS Atoll electro-optical system.
The Sh121 consists of the N036 Byelka radar system and L402 Himalayas electronic countermeasures system.
On 8 August 2007, Russian Air Force Commander-in-Chief (CinC) Alexander Zelin was quoted by Russian news agencies that the programme's development stage was complete and construction of the first aircraft for flight testing would begin, and that by 2009 there would be three fifth-generation aircraft ready. The prototype's maiden flight was repeatedly postponed from early 2007 after encountering unspecified technical problems. In August 2009, Alexander Zelin acknowledged that problems with the engine and in technical research remained unsolved. In 2009, the aircraft's design was officially approved. The fighter is designed to have supercruise, supermaneuverability, stealth, and advanced avionics to overcome the prior generation fighter aircraft as well as ground and naval defences. The Su-57 is intended to succeed the MiG-29 and Su-27 in the Russian Air Force. On 28 February 2009, Mikhail Pogosyan announced that the air-frame was almost finished and that the first prototype should be ready by August 2009. On 20 August 2009, Pogosyan said that the first flight would be by year's end. Konstantin Makiyenko, deputy head of the Moscow-based Centre for Analysis of Strategies and Technologies said that "even with delays", the aircraft would likely make its first flight by January or February, adding that it would take five to ten years for commercial production.
In 2007, Russia and India agreed to jointly develop the Fifth Generation Fighter Aircraft Programme (FGFA) for India. In early 2018 India pulled out of the FGFA project, which it believed did not meet its requirements for stealth, combat avionics, radars and sensors by that time. This news lead some observers to question the future of the whole Su-57 project. The izdeliye 30 powerplant is designed to be a drop-in replacement for the 117 with minimal changes to the airframe.
The first taxi test was successfully completed on 24 December 2009. Flight testing began with T-50-1, the first prototype aircraft, on 29 January 2010. Piloted by Sergey Bogdan, the aircraft's 47-minute maiden flight took place at KnAAPO's Dzemgi Airport in the Russian Far East. The first production aircraft was expected to be delivered in 2019 with a second to follow in 2020.
On the first prototype, composites comprise 25% of the structural weight and almost 70% of the outer surface. Second stage prototype was to increase the usage of composite material, as well as stronger airframe, elongated tail, wider wingspan and the possibility to install newer engines.
Sukhoi T-50, 2010
The second aircraft was to initially start flight testing in late 2010; this was delayed until early 2011. On 3 March 2011, the second prototype, T-50-2, completed a 44-minute test flight. The first two prototypes lacked radar and weapon control systems. On 14 March 2011, the fighter achieved supersonic flight at a test range near Komsomolsk-on-Amur. The T-50 was displayed publicly for the first time at the 2011 MAKS Airshow. On 3 November 2011, the fighter reportedly performed its 100th flight. More than 20 test flights were made in the next nine months.
In 2011, the Russian Defence Ministry planned on purchasing the first 10 evaluation aircraft after 2012 and then 60 production standard aircraft after 2016. In December 2014, the Russian Air Force planned to receive 55 fighters by 2020. Russian Deputy Minister of Defence Yury Borisov stated in 2015 that the Air Force would slow production, reduce its initial order to 12 fighters, and retain large fleets of fourth-generation fighters due to the nation's economy.
T-50 at the MAKS 2011 air show
On 22 November 2011, the third prototype, T-50-3, took its first flight from KnAAPO's airfield in Komsomolsk-on-Amur, piloted by Sergey Bogdan. The aircraft spent over an hour in the air, and was subjected to basic stability and power-plant checks. It differs from the other prototypes by lacking a pitot tube. At this time all 14 test aircraft were expected to fly by 2015. T-50-3 was the first prototype to fly with an AESA radar. Originally scheduled for the end of 2011, these flights occurred in August 2012, and showed performance comparable to existing radars.
The fourth prototype had its first flight on 12 December 2012 and joined the other three aircraft in testing near Moscow a month later. By the end of 2013, five prototypes were flown, with the fifth prototype having its first flight on 27 October 2013; with this flight the programme has amassed more than 450 flights. The first aircraft for State testing was delivered on 21 February 2014.
The 929th State Flight Test Centre (GLITS) received its first T-50 prototype for further testing and state trials in March 2014, and external weapon trials started in May 2014.
On 10 June 2014, the fifth flying prototype, aircraft T-50-5, was severely damaged by an engine fire after landing. The pilot managed to escape unharmed. Sukhoi stated that the aircraft will be repaired, and that the fire "will not affect the timing of the T-50 test program".
On 8 February 2018, then Deputy Minister of Defence Yury Borisov said that the first stage of state trials had been concluded and that the combat trials were on schedule. He also reported that the contract for an initial batch of 12 aircraft was to be signed in 2018. First two serial units were ordered in August 2018, with term of delivery by 2020. State trials were to be complete in 2019.
The fifth prototype, T-50-5 hull number 055, was severely damaged by an engine fire after landing in June 2014. The aircraft was returned to flying condition after cannibalizing components from the unfinished sixth prototype.
The sixth prototype first flew on 27 April 2016.
On 5 December 2017, the first flight of the second Su-57 prototype (T-50-2, bort no. 052) fitted with the izdeliye 30 engine took place at the Gromov Flight Research Institute. The 17–minute test flight was carried out by Sergei Bogdan, Sukhoi chief test pilot. The izdeliye 30 engine was installed on the port-side engine position while the izdeliye 117 engine remained on the starboard side. The izdeliye 30 features a new serrated nozzle compared to flat one on 117, and is slightly shorter than the izdeliye 117 nozzle.
On 21 February 2018, two Su-57s were spotted landing at the Russian Khmeimim air base in Syria. The aircraft were deployed along with four Sukhoi Su-35 fighters, four Sukhoi Su-25s, and one Beriev A-50 AEW&C aircraft. Three days later two more Su-57s were reported to have arrived in Syria. On 1 March 2018, the Russian Defence Minister Sergey Shoygu confirmed that the two Su-57s spent two days in Syria and successfully completed a trials program, including combat trials during which parameters of weapons work were monitored.
On 25 May 2018, the Russian Defence Ministry revealed that during the February 2018 deployment to Syria, a Su-57 fired a cruise missile in combat, likely a Kh-59MK2.
On 18 November 2018, the Russian Defence Ministry posted a video of the fighters’ flights on Twitter, and announced that Su-57 performed 10 flights during its trip to Syria. However, the video did not specify when the test flights took place.
In April 2018, it was reported that India is withdrawing from the program. India has become increasingly disappointed with the project's progress after years of negotiations, delays, and struggles with Russia. India is also not satisfied with the capabilities of Su-57, the basis of the FGFA with one of the main issues being the Su-57's insufficient stealth design.
117 engine compressor stall at MAKS-2011
On 22 August 2018, during the International Military-Technical Forum «ARMY-2018», the Russian Defence Ministry and the JSC Sukhoi signed the first contract for delivery of two serial Su-57 fighters. The deliveries of the first two such aircraft are scheduled for 2019 and 2020, respectively.
In January 2019, the third flyable Su-57 prototype (bort. no 053) was being actively used as a flying laboratory for testing of onboard radio-electronic systems of the new sixth-generation Sukhoi Okhotnik UCAV.
On 28 March 2019, the export version of the Su-57, dubbed Su-57E, "E" for Eksportny ("Export"), was first promoted to international customers during the 2019 Langkawi International Maritime and Aerospace Exhibition. The aircraft was officially unveiled at the 2019 MAKS International Aviation and Space Salon.
On 15 May 2019, Russian President Vladimir Putin announced that 76 aircraft will be purchased and delivered to the Air Force by 2028. This came after the price of the Su-57 and equipment was reduced by 20%. The contract for the 76 aircraft was formally signed on 27 June 2019 at the International Military-Technical Forum «ARMY-2019».

Russia’s Sukhoi Su-57, entered serial production under the terms of a contract signed June 2019 United Aircraft Corporation was to produce 76 Su-57s, with the first jet likely to enter service before the end of 2019. JSC Sukhoi started the serial production of the aircraft in late July 2019.
The Su-57 will also be a launch platform for the Kinzhal (“Dagger”) hypersonic missile.
Prototype for static ground testing
Prototype for integration testing
Fuselage number 051
First flyable prototype; first flight on 29 January 2010.
Fuselage number 052
Second flyable prototype; first flight on 3 March 2011, first supersonic flight on 24 March. First prototype flight-tested with an izdeliye 30 engine, first flight on 5 December 2017.
Fuselage number 053
Third flyable prototype; first flight on 22 November 2011. In 2012, became the first prototype to be equipped with AESA radar, first tested in flight on 8 August 2012.
Fuselage number 054
Fourth flyable prototype, and the first one equipped with the complete set of avionics; first flight on 12 December 2012.
T-50-5 / T-50-5R
Fuselage number 055
Fifth flyable prototype, first flight on 27 October 2013. Heavily damaged by fire in June 2014, repaired and renamed to T-50-5R, first flight after repairs on 16 October 2015.
Cannibalized for parts to repair T-50-5.
Second-stage prototype for static ground testing.
(also called T-50-6)
Fuselage number 056
Sixth flyable prototype (first flyable second-stage prototype); first flight on 27 April 2016. The fuselage cover panels are partially replaced by composite materials. The rear part of the fuselage (in which the EW complex is located) was elongated, the shape of the lower fuselage in the tail section, the hatches and airbleed doors were also changed.
Fuselage number 058
Seventh flyable prototype (second flyable second-stage prototype); first flight on 17 November 2016.
Fuselage number 509
Eighth flyable prototype (third flyable second-stage prototype); first flight on 24 April 2017. Testing final version of avionics intended for serial production.
Fuselage number 510
Tenth flyable prototype, first flight on 23 December 2017. It is supposed to be the last prototype.
Fuselage number 511
Ninth flyable prototype, first flight on 6 August 2017. Testing version of the airframe intended for serial production.
Engines: 2 × Saturn AL-41F1 (initial production) turbofans with thrust vectoring, 93.1 kN (20,900 lbf) thrust each dry, 147.2 kN (33,100 lbf) with afterburner
2 × izdeliye 30 (later production) turbofans with thrust vectoring, 107.9 kN (24,300 lbf) thrust each dry, 176.6 kN (39,700 lbf) with afterburner
Wingspan: 13.95 m (45 ft 9 in)
Length: 19.8 m (65 ft 0 in)
Height: 4.74 m (15 ft 7 in)
Wing area: 78.8 sq.m (848 sq ft)
Empty weight: 18,000 kg (39,683 lb)
Typical mission weight, 29,270 kg (64,530 lb) at full load
Max takeoff weight: 35,000 kg (77,162 lb)
Fuel capacity: 10,300 kg (22,700 lb) internally
Maximum speed: Mach 2 (2,120 km/h; 1,320 mph) at altitude
Supercruise: Mach 1.6 (1,710 km/h; 1,060 mph) at altitude
Range: 3,500 km (2,200 mi, 1,900 nmi) subsonic, 4,500 km from 2 outboard fuel tanks
Supersonic range: 1,500 km (930 mi, 810 nmi)
Service ceiling: 20,000 m (66,000 ft)
g limits: +9.0
Wing loading: 317 kg/sq.m (65 lb/sq ft) typical mission weight
AL-41F1: 1.02 (1.19 at typical mission weight)
izdeliye 30: 1.15 - 1.2 (1.36 at typical mission weight)
Guns: 1 × 30 mm Gryazev-Shipunov GSh-30-1 autocannon in right LEVCON root
Hardpoints: 12 hardpoints (6 × internal, 6 × external)
Crew: 1


Engines: 2 x 147 kN AL-41F1 turbofans
Max Take-off weight: 37000 kg / 81571 lb
Empty weight: 18500 kg / 40786 lb
Wingspan: 14 m / 46 ft 11 in
Length: 19.8 m / 66 ft 0 in
Height: 6.05 m / 20 ft 10 in
Wing area: 78.8 sq.m / 848.20 sq ft
Max. speed: 2100-2500 km/h / 1305 - 1553 mph
Ceiling: 20000 m / 65600 ft
Rate of climb: 350 m/sec








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