The Russian Aerospace Forces will receive first units of the Sukhoi T-50 (PAK FA – «Multifunctional Frontline Fighter») fifth-generation fighter aircraft in 2017, Col. Gen. Viktor Bondarev, the Russian Aerospace Forces Commander-in-Chief, said on June 4.
Russia’s new stealth fighter made an eyebrow-raising surprise appearance on June 5 – soaring over the Crimean Peninsula (Chauda practice range), taking part in the 2016 Aviadarts.
«There are five T-50 fighters being tested at the Chkalov flight testing center to enter service in 2017», Bondarev told reporters.
The aircraft is a stealthy, single-seat, twin-engine, supermaneuverable, multirole fighter with supercruise capability, designed for air superiority and attack roles. It possesses advanced avionics such as active phased array radar and sensor fusion.
The plane has the following general characteristics: crew – 1 person, maximum speed – 2600 km/h, climbing speed – 330 km/h, maximum flying distance – 5500 km, operational endurance – up to 5.8 hours, operational ceiling – 20 km, maximum take-off weight – 35480 kg, maximum operational load – 10 tons. During testing the aircraft managed to achieve a 384 meters per second climbing rate. Such a climbing speed would’ve allowed the warplane to reach an altitude equal to the peak of Mount Everest, the highest mountain on Earth, in a mere 23 seconds.
The T-50 has a blended wing body fuselage and incorporates all-moving horizontal and vertical stabilizers. The advanced flight control system and thrust vectoring nozzles make the aircraft highly maneuverable in both pitch and yaw, enabling it to perform very high angles of attack maneuvers.
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.
Internal weapons carriage eliminates drag from external stores and enables higher performance compared to external carriage. The airframe incorporates planform edge alignment to reduce its radar cross-section; the leading and trailing edges of the wings and control surfaces and the serrated edges of skin panels are carefully aligned at several specific angles in order to reduce the number of directions the radar waves can be reflected. The aircraft uses radar absorbing material. The canopy is treated with a coating to minimize the radar return of the cockpit and pilot. The production aircraft incorporates radar blockers in front of the engine fan to hide it from all angles.
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, its predecessor). Pre-production and initial production batches of the T-50 will use interim engines, a pair of NPO Saturn AL-41F1 (the Izdeliye 117). The engine has a thrust to weight ratio of 10.5:1.
The two 117 engines incorporate thrust vectoring nozzles whose rotational axes are each canted at an angle. 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 by the engines.
The PAK FA will carry an impressive array of missiles capable of engaging other aircraft such as AWACS, C4ISTARs (Command, Control & Communication, Intelligence, Surveillance, Target Acquisition and Reconnaissance) and fighters at long ranges, in addition to ships, radars, and other surface targets. For air-to-air combat, the T-50 is expected to carry four beyond-visual-range missiles in its two main weapons bays and two short-range missiles in the wing root weapons bays. The primary medium-range missile is the active radar-homing K-77M – an upgraded R-77 (Vympel) variant with an active electronically scanned array seeker and conventional rear fins.
The short-range missile is the infrared-homing («heat seeking») K-74M2, an upgraded R-74 variant with reduced cross-section for internal carriage.
A clean-sheet design short-range missile designated K-MD is being developed to eventually replace the K-74M2. For longer ranged applications, four large beyond-visual-range missiles can be carried, with two in each main weapons bay. The main bays can also accommodate air-to-ground missiles such as the Kh-38M, as well as multiple 250 kg KAB-250, or 500 kg KAB-500 precision guided bombs.
For missions that do not require stealth, the T-50 can carry stores on its six external hardpoints. PAK FA chief designer Alexander Davydenko has said that there is a possibility of the installation of BrahMos supersonic cruise missile on the PAK FA and its FGFA derivative.
Only one or two such missiles may be carried due to heavy weight of the BrahMos.
The aircraft has an internally mounted 9A1-4071K (GSh-301) 30 mm cannon near the right LEVCON root.
The T-50 has a glass cockpit with two 38 cm (15 in) main multi-functional LCD displays. Positioned around the cockpit are three smaller control panel displays. The cockpit has a wide-angle (30° by 22°) head-up display, and Moscow-based Geofizika-NV provides a new NSTsI-V helmet-mounted sight and display for the ZSh-10 helmet. 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 T-50 prototypes are currently fitted with the Saturn 116 engine, NIIP Irbis radar, and certain avionics that are also on the Su-35s.
These components will be phased out after 2020 when the upgraded components are ready for production. The new engine, the Izdeliye 30, will enter service in 2020.
Many of the technical details are still classified, especially since the program is still not in the main production stage. However, the general consensus is that the T-50 is more maneuverable than the US rivals – the F-35 and F-22. The plane has a comparative advantage in air engagements. Compared to the F-22, the PAK FA is faster, has a longer operational range, and better target detection. «It certainly has greater agility with its combination of thrust vectoring, all moving tail surfaces, and excellent aerodynamic design, than does the F-35», said former US Air Force intelligence chief Lt. General David Deptula.
All told, the aircraft has the following distinctive features that meet the requirements for the fifth generation fighter: supermaneuvrability (thanks to engines with controlled thrust vector), in-flight refueling system, the ability to cruise at supersonic speed without the use of afterburner, low-radar cross-section, short take-off and landing and versatility in combat employment.
The aircraft is going through testing, but India and Vietnam are already on the list of potential buyers.
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After the fall of the Soviet Union the Russian aircraft industry faced hard times. No one in the middle of the 1990s could even imagine that such achievements were possible. Aviation is a very complicated industry. Despite all the snags on the way, Russia has created several unique aircraft. Now it is testing the fifth generation aircraft that is second to none in the contemporary world. The emergence of the Russian Sukhoi PAK-FA marks the end of the United States' quarter century long monopoly on the design of very low observable (VLO) or stealth aircraft.