Sukhoi PAK-FA/T-50

**PAK FA
T-50**

 **Primary Users** | Russian Air Force
 **Produced** | 2009 -

The **PAK-FA/T-50**, more often known as the **T-50** or sometimes the **Su-50** is a fifth-generation fighter designed for the Russian Air Force The aircraft is a stealthy, single-seat, twin-engine jet fighter, and was the first operational aircraft in Russian service to use stealth technology. It is a multirole fighter designed for air superiority and attack roles. The fighter also has supercruise, stealth, supermaneuverability, and advanced avionics to overcome the prior generation of fighter aircraft as well as ground and maritime defences.

The T-50 was the successor to the MiG-29 and Su-27 in the Russian Air Force and serve as the basis for the Fifth Generation Fighter Aircraft (FGFA) being co-developed by Sukhoi and Hindustan Aeronautics Limited (HAL) for the Indian Air Force. The T-50 prototype first flew on 29 January 2010 and the first production aircraft began delivery to the Russian Air Force starting in mid-2016. The prototypes and initial production batch was delivered with a highly upgraded variant of the AL-31F used by the Su-27 family as interim engines while a new clean-sheet design powerplant is currently under development. The aircraft is expected to have a service life of up to 35 years.

## Development

### Origins

In the late 1980s, 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 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 program designed to meet these requirements, the MFI, resulted in Mikoyan's selection to develop the MiG 1.44. Though not a participant in the MFI, Sukhoi started its own program in the early 1990s to develop technologies for a next-generation fighter aircraft, resulting in the S-37, later designated as the Su-47. Due to a lack of funds after the collapse of the Soviet Union, the MiG 1.44 program was repeatedly delayed and the first flight of the prototype did not occur until 2000, nine years behind schedule. The MiG 1.44 was subsequently canceled and a new program for a next-generation fighter, PAK FA, was initiated. The program requirements reflected the capabilities of Western fighter aircraft, such as the Eurofighter Typhoon and F-22 Raptor. Following a competition between Sukhoi, Mikoyan, and Yakovlev, in 2002, Sukhoi was selected as the winner of the PAK FA competition and selected to 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 multirole 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 will compete for the definitive second stage engines.

### Procurement

In 2007, Russia and India agreed to jointly develop the Fifth Generation Fighter Aircraft Programme (FGFA) for India. In September 2010, it was reported that India and Russia had agreed on a preliminary design contract where each country invests $6 billion; development of the FGFA fighter was expected to take 8–10 years. The agreement on the preliminary design was to be signed in December 2010.

The Russian Air Force is expected to procure more than 150 PAK FA aircraft, the first of which is slated to be delivered in 2016. India plans on acquiring modified PAK FA as a part of its Fifth Generation Fighter Aircraft (FGFA) program. It originally planned on buying 166 single-seat and 44 two-seat variants, but this has been reduced to 130-145 single-seat aircraft and the requirement for 45-50 twin-seat fighters has been dropped by 2014. The Russian Defence Ministry plan on purchasing the first 10 evaluation example 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. But Yuri Borisov, Russia's deputy minister of defence for armaments stated in March 2015 that the Air Force will slow PAK FA production and reduce its initial order to 12 jets due to the nation's deteriorating economy. Due to the aircraft's complexity and rising costs, the Russian Air Force will retain large fleets of fourth-generation Sukhoi Su-27 and Su-35S.

## Design

The PAK FA is a fifth generation multirole fighter aircraft and the first operational stealth aircraft for the Russian Air Force. Although most information is classified, sources within the Sukhoi company and Defense Ministry have openly stated that the aircraft will be stealthy, supermaneuverable, have supercruise capability, incorporate substantial amounts of composite materials, and possess advanced avionics such as active phased array radar and sensor fusion.

The T-50 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 allow the aircraft to be 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 and the Bell maneuver and flat rotations with little altitude loss. The aircraft's high cruising speed and normal operating altitude is also expected to give it a significant kinematic advantage over prior generations of aircraft.

The T-50 makes extensive use of composites, comprising 25% of the structural weight and almost 70% of the outer surface. Weapons are housed in two tandem main weapons bays between the engine nacelles and smaller bulged, triangular-section bays near the wing root. Internal weapons carriage eliminates drag from external stores and enables higher performance compared to external carriage. Advanced engines and aerodynamics enable the T-50 to supercruise, sustained supersonic flight without using afterburners. Combined with a high fuel load, the T-50 has a supersonic range of over 1,500 km, more than twice that of the Su-27. In the T-50'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.

## Operators

**Operators of the T-50:**

* Albania
* Brazil
* Greece
* Template:Country data Myanmar Myanmar
* Russia
* Serbia
* South Africa