PAK FA
PAK FA T-50
Role	Stealth multirole fighter
National origin	Russia
Manufacturer	Sukhoi
First flight	29 January 2010[1][2][3]
Introduction	2015/2016 (planned)[4][5][6][7]
Status	Test flight / pre-production
Primary users	Russian Air Force Russian Navy[8]
Number built	4 with 3 flown [9][10]
Program cost	US$8–10 billion (est.)[11][12][13]
Unit cost	US$47.5–57 million[14]
Variants	Sukhoi/HAL FGFA

The Sukhoi PAK FA (Russian: Сухой ПАК ФА, Russian: Перспективный авиационный комплекс фронтовой авиации, Perspektivny aviatsionny kompleks frontovoy aviatsii, literally "Prospective Airborne Complex of Frontline Aviation") is a twin-engine jet fighter being developed by Sukhoi for the Russian Air Force. The Sukhoi T-50 is the prototype for PAK FA.^[15] The PAK FA is one of only a handful of stealth jet programs globally.^[16]

The PAK FA, when fully developed, is intended to be the successor to the MiG-29 and Su-27 in the Russian inventory and serve as the basis of the Sukhoi/HAL FGFA being developed with India.^[17][18] A fifth generation jet fighter, the T-50 performed its first flight 29 January 2010.^[3][19] Its second flight was on 6 February and its third on 12 February 2010. By 31 August 2010, it had made 17 flights and by mid-November, 40 in total. The second prototype was to start its flight test by the end of 2010, but this was delayed until March 2011.^{[20][21][22][23][24]}

Sukhoi director Mikhail Pogosyan has projected a market for 1,000 aircraft over the next four decades, which will be produced in a joint venture with India, 200 each for Russia and India and 600 for other countries.^[25] He has also said that the Indian contribution would be in the form of joint work under the current agreement rather than as a joint venture.^[26] The Indian Air Force will "acquire 50 single-seater fighters of the Russian version" before the two seat FGFA is developed.^[27] The Russian Defense Ministry will purchase the first 10 aircraft after 2012 and then 60 after 2016.^[28][29] The first batch of fighters will be delivered with current technology engines.^[30] The PAK-FA is expected to have a service life of about 30–35 years.

Development[link]

In the late 1980s, the Soviet Union outlined a need for a next-generation aircraft to replace its MiG-29s and Su-27s in front line service. Two projects were proposed to meet this need – the Sukhoi Su-47 and the Mikoyan Project 1.44. In 2002, Sukhoi was chosen to lead the design for the new combat aircraft.^[31]

T-50 in-flight at MAKS 2011

The Tekhnokompleks Scientific and Production Center, Ramenskoye Instrument Building Design Bureau, the Tikhomirov Scientific Research Institute of Instrument Design, the Ural Optical and Mechanical Plant (Yekaterinburg), the Polet firm (Nizhny Novgorod) and the Central Scientific Research Radio Engineering Institute (Moscow) were pronounced winners in the competition held in the beginning of 2003 for the development of the avionics suite for the fifth-generation airplane. NPO Saturn has been determined the lead executor for work on the engines for this aircraft.^{[citation needed]}

The Novosibirsk Aircraft Production Association has begun construction of the fifth-generation multirole fighter. This work is being performed at Komsomol'sk-on-Amur together with Komsomolsk-on-Amur Aircraft Production Association; the enterprise's general director, Fedor Zhdanov reported during a visit to NAPO by Novosibirsk Oblast's governor Viktor Tolokonskiy on 6 March 2007. "Final assembly will take place at Komsomol'sk-on-Amur, and we will be carrying out assembly of the fore body of this airplane", Zhdanov specified.^{[citation needed]}

On 8 August 2007, Russian Air Force Commander-in-Chief (CinC) Alexander Zelin was quoted by Russian news agencies that the development stage of the PAK FA program is complete and construction of the first aircraft for flight testing would begin.^[32] Zelin also said that by 2009 there would be three fifth-generation aircraft ready. "All of them are currently undergoing tests and are more or less ready", he said.^[33] In the summer of 2009 the design was approved.^[31]

On 11 September 2010, it was reported that Indian and Russian negotiators had agreed on a preliminary design contract, subject to Cabinet approval. The joint development deal would have each country invest $6 billion and take 8–10 years to develop the FGFA fighter.^[34] The agreement on the pre-design of the fighter was to be signed in December 2010.^[35] The preliminary design will cost $295 million and will be complete within 18 months.^[36] On 17 August 2011, Russian state-run media reported that the new fighter will cost Russia and India $6 billion to develop, and that India would shoulder about 35% of the cost.^[37]

In August 2011, the Russian Air Force said that the Sukhoi T-50 will enter service in 2014-2015. "We will receive a T-50 prototype in 2013," CinC Zelin told reporters. "Mass produced aircraft will not arrive until 2014-2015."^[38] Former deputy defense minister Vitaly Shlykov has cast doubt on the industrial capacity of Russia to produce the aircraft in significant numbers.^[39]

Flight testing[link]

Prototype T-50 in flight

The T-50's maiden flight had been repeatedly postponed since early 2007 as the aircraft encountered unspecified technical problems. Alexander Zelin admitted as recently as August 2009 that problems with the engine and in technical research remained unsolved.^[40] On 28 February 2009, Mikhail Pogosyan announced that the airframe for the aircraft was almost finished and that the first prototype should be ready by August 2009.^[41] 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.^[42]

On 8 December 2009, Deputy Prime Minister Sergei Ivanov announced that the first trials with the fifth-generation aircraft would begin in 2010.^[43] The first taxi test was successfully completed on 24 December 2009.^[44][45][46] Piloted by Hero of the Russian Federation Sergey Bogdan, the aircraft's 47-minute maiden flight took place on 29 January 2010 at KnAAPO's Dzemgi Airport in the Russian Far East.^{[3][47][48][49]}

A second prototype was first planned to join the flight testing in the fourth quarter of 2010 but was postponed. On 3 March 2011, it was reported that the second aircraft had made a successful 44-minute test flight.^[20] These first two aircraft will lack radar and weapon control systems. The third and fourth aircraft, to be added in 2011, will be fully functional test aircraft.^[50] On 14 March 2011, the aircraft achieved supersonic flight at a test range near Komsomolsk-on-Amur in Siberia.^[51]

PAK FA T-50 with landing gear down, April 2010

The T-50 was displayed publicly for the first time at the 2011 MAKS Airshow. Russian Prime Minister Vladimir Putin was in attendance.^[52][53] In June 2011, an unauthorized video was made of the Sukhoi PAK FA in flight displaying a variety of aerobatic moves.^[54] On 3 November 2011, The PAK FA program achieved its 100th flight.^[55]

The third prototype, T-50-3, was expected to be the first prototype to fly with an AESA radar by the end of 2011.^[56] On 22 November 2011, 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 powerplant checks.^[57] It differs from the other prototypes in the way it lacks a pitot tube.

All 14 test aircraft are scheduled to fly by 2015.^[58]

Naval and other versions[link]

Navalized Sukhoi T-50 PAK FAs will be deployed on the Russian aircraft carrier Admiral Kuznetsov and future Russian aircraft carriers.^[59] There will be a competition between the Sukhoi, Mikoyan and Yakovlev design bureaux to choose the new naval aircraft.^[8]

Alexei Fedorov has said that any decision on applying fifth-generation technologies to produce a smaller fighter (comparative to the F-35) must wait until after the heavy fighter, based on the T-50, is completed.^[60]

Design[link]

NIIP's AESA radar for the PAK FA on display at the 2009 MAKS airshow

Although most of information about the PAK FA is classified, it is believed from interviews with people in the Russian Air Force and Defense Ministry that it will be stealthy,^[12] have the ability to supercruise, be outfitted with the next generation of air-to-air, air-to-surface, and air-to-ship missiles, incorporate a fix-mounted AESA radar with a 1,500-element array^[61] and have an "artificial intellect".^[62]

According to Sukhoi, the new radar will reduce pilot load and the aircraft will have a new data link to share information between aircraft.^[63]

Composites are used extensively on the T-50 and comprise 25% of its weight and almost 70% of the outer surface.^[50] It is estimated that titanium alloy content of the fuselage is 75%. Sukhoi's concern for minimizing radar cross-section (RCS) and drag is also shown by the provision of two tandem main weapons bays in the centre fuselage, between the engine nacelles. Each is estimated to be between 4.9-5.1 m long. The main bays are augmented by bulged, triangular-section bays at the wing root.^[64]

The Moskovsky Komsomolets reported that the T-50 has been designed to be more maneuverable than the F-22 Raptor at the cost of making it less stealthy than the F-22.^[65] One of the design elements that have such an effect is the Leading Edge Vortex Controller (LEVCON).

Avionics[link]

The PAK FA's SH121 radar complex includes three X-band AESA radars located at the front and sides of the aircraft. These will be accompanied by L-band radars on the wing leading edges.^[66][67] L-band radars are proven to have increased effectiveness against very low observable, or stealthy, targets which are optimized only against X-band frequencies, but their longer wavelengths reduce their resolution. However the initial prototypes will use legacy passive electronically scanned array radar.^{[68][verification needed]}

The PAK FA will feature an infra-red search and track optical/IR search and tracking system, based on the OLS-35M which is currently in service with the Su-35S.^{[citation needed]}

Engines[link]

PAK FA was expected to use a pair of Saturn 117S engines on its first flights. In fact, the PAK FA used a completely new engine 117 (AL-41F1) in its first flight, as stated by NPO Saturn.^[69] The 117S (AL-41F1A) is a major upgrade of the AL-31F based on the AL-41F intended to power the Su-35BM, producing 142 kN (32,000 lb) of thrust in afterburner and 86.3 kN (19,400 lb) dry. The engine is not based on the Saturn 117S

The 117 (AL-41F1) is a new 5th generation engine custom built for Russia’s fifth-generation stealth fighter jet PAK-FA according to Sukhoi director Mikhail Pogosyan. Pogosyan has clarified that claims that fifth-generation fighter allegedly has an old engine are wrong. Such claims are made by people with limited knowledge, he said. Though most parameters of the new fifth-generation engine remains classified, Pogosyan provided some information on the new engine, The engine thrust was increased by 2.5 tonnes when compared with the AL-31 engine, while the engine weight was cut by 150 kilograms (330 lb). That allowed the new jet to supercruise, or sustain supersonic cruise speed without afterburning.^[70]

The Saturn Research and Production center made digitally controlled system (FADEC) of Project 117 Engine. The new engine produces 33,000 lbs (147 kN) of thrust in afterburner has a Dry weight of 1420 kilogram and T:W ratio of 10.5:1^[71]

Mikhail Pogosyan further mentioned that this engine (117) meets the Russian Air Force's requirements. This is not an intermediate product made particularly for test flights. The engine will be installed in production PAK-FA fighter which will be supplied to the Russian Air Force and prospective foreign clients he said.^[72] The engine generates a larger thrust and has a complex automation system, to facilitate flight modes such as maneuverability. It is expected that each engine will be able to independently vector its thrust upwards, downward or side to side. Vectoring one engine up with the other one down can produce a twisting force. Therefore the PAK FA would be the first fifth generation fighter with full 3-D thrust vectoring along all three aircraft axes: pitch, yaw and roll. These engines will incorporate infrared and RCS reduction measures.^[73][74]

Armament[link]

The PAK FA has a reported maximum weapons load of 7,500 kg.^[75] It has an apparent provision for a cannon (most likely GSh-301), and could possibly carry two 30 mm cannons.^[30] The PAK FA has two internal bays estimated at 4.6-4.7 metres by 1-1.1 metres.^[76] Some sources suggest two auxiliary internal bays for short range AAMS and six external hardpoints.^{[citation needed]}

Two Izdeliye 810 Extended beyond visual range missiles per weapons bay. Multiple Izdeliye 180 / K77M beyond visual range missiles. K74 and K30 within visual range missiles can also be carried.^[76] Two KH38M or KH58 USHK air-to-ground missiles per weapons bay. Multiple 250–500 kg precision guided bombs per weapons bay,^[76] with a maximum of 10 bombs in internal bays.^[75] Other possible loads include one 1,500 kg bomb per weapons bay or two 400 km+ range anti-AWACS weapons (such as the RVV-BD ) on external hardpoints.^[77][78]

PAK FA chief designer Alexander Davydenko has said that the possibility of the installation of BrahMos supersonic missile on the PAK FA and its FGFA derivative. However, it is unclear how these missiles will be installed, though it can be one or two missiles only due to heavy weight of the BrahMos.^[79]

The initial weapons for the PAK FA include Kh-35UE (AS-20 "Kayak"), Kh-38ME, Kh-58UShKE (AS-11 "Kilter"), and RVV-MD (AA-11 "Archer") missiles.^[80]

Operational history[link]

Testing[link]

The first flight video shows that PAK FA has no conventional rudders, its vertical tails are fully movable.^[81] This special tail fin design is mechanically similar to V-tails used by the Northrop YF-23 in 1990s,^[82] but is supplemented by dedicated horizontal stabilators (as on the F-22). The T-50 has wing leading-edge devices above the jet engine intakes that have been called a challenge for signature control.^[83]

Exports[link]

Russia was said to be interested in offering the PAK-FA for South Korea's next generation jet fighter.^[84] South Korea's defence procurement agency confirmed that the Sukhoi PAK-FA was a candidate for the Republic of Korea Air Force's next-generation fighter (F-X Phase 3) aircraft,^[85] however Sukhoi failed to enter the bidding competition by the January 2012 deadline.^[86]

Russia's Centre for Analysis of World Arms Trade predicts that the PAK FA will be available for export in 2025.^[87] Though this "export version" may refer to the Sukhoi/HAL FGFA.^[88]

Ruslan Pukhov, director of the Centre for Analysis of Strategies and Technologies, has projected that Vietnam will be the second export customer for the fighter.^[89]

Specifications[link]

Т-50 3 views diagram

Because the aircraft is in development, these specifications are preliminary and are taken as estimates from the available images.

Data from warfare.ru,^[90] pravda.ru^[91]

General characteristics

• Crew: 1
• Length: 19.8 m (65.9 ft)
• Wingspan: 14 m (46.6 ft)
• Height: 6.05 m (19.8 ft)
• Wing area: 78.8 m² (848.1 ft²)
• Empty weight: 18,500 kg (40,785 lb)
• Loaded weight: 26,000 kg (57,320 lb)
• Useful load: 7,500 kg (combat load) (16,534 lb)
• Max. takeoff weight: 37,000 kg (81,570 lb)
• Powerplant: 2 × AL-41F1 for prototypes^{[N 1][92]} turbofan, 147 kN (33,047 lb) for prototypes;^[93] 157+ kN (34,620+ lbf) for definitive engine version^[93] each
• Fuel capability: 10,300 kg (22,711 lb)^[90]

Performance

• Maximum speed: Mach 2+, 2,100-2,600 km/h^[90][94][92] (1,300-1,560 mph) ; at 17,000 m (45,000 ft) altitude
• Cruise speed: 1,300-1,800 km/h^[92] (808-1,118 mph)
• Ferry range: 5,500 km^[77] (3,417 mi)
• Service ceiling: 20,000 m (65,600 ft)
• Rate of climb: 350 m/s (68,900 ft/min)
• Wing loading: 330-470 kg/m² (67-96 lb/ft²)
• Thrust/weight: 1.19^[90]
  
• Maximum g-load: 9+ g^[90]

Armament

• Guns: None on prototype. Apparent provision for a cannon (most likely GSh-301). Possible two 30 mm cannons.^[30]
• Hardpoints: Two internal bays^[76] Other sources suggest two auxiliary internal bays for short range AAMS and six external hardpoints.

Avionics
N036 BRLS AFAR/AESA built by Tikhomirov NIIP and based on Tikhomirov NIIP N035 Irbis-E. It will be the second aircraft based AESA Radar to be built by Russia, the first being the Phazotron NIIR ZHUK-A Radar in the MiG-35.^[95]

See also[link]

Aviation portal

Related development

• Sukhoi/HAL FGFA
• Mikoyan Project 1.44
• Sukhoi Su-35BM^{[N 2]}
• Sukhoi Su-47
  

Aircraft of comparable role, configuration and era

• Chengdu J-20
• Lockheed Martin F-22 Raptor
• Mikoyan LMFS
• Northrop YF-23
• Advanced Medium Combat Aircraft
  

Related lists

• List of fighter aircraft
• List of military aircraft of the Soviet Union and the CIS
  

References[link]

Notes

Citations

Bibliography

External links[link]

Wikimedia Commons has media related to: PAK FA

Official websites

• Sukhoi Company — Primary contractor

General information

• PAK FA - Global Security.org
• The T-50's Flight to the Future - GrandeStrategy
• PAK FA info & pictures - Paralay.com (Russian)
• PAK FA - Russian Military Analysis
• Sukhoi PAK FA - Redstar.gr

Technology

• Т-50: технологии взлёта - Technical development video (Russian)

News reports and articles

• FARNBOROUGH 2008: Russian air force to receive Sukhoi PAK FA - to be equivalent of the F-22 Raptor
• Article from India Times
• Article on Flight International website with artistic image of PAK FA from NPO Saturn (April 04 2007)
• Brazil, Russia to build jet fighter, Associated Press
• Australian Analysis of PAK-FA

Flight videos and photos:

• Maiden flight video on YouTube
• Another video on YouTube
• Photos of the first and second prototype of PAK FA (Т-50) in flight (2010-2011).