User:Para6371/Su-47

This page is about the aircraft at one time designated S-37. For the aircraft designated Su-37, see Sukhoi Su-37.

Su-47 Berkut
A Su-47B of the VVS at MAKS 2023
General information
Type	Fighter/Multirole
Manufacturer	Sukhoi
Designer	Mikhail Pogosyan
Status	In service
Primary user	Soviet Air Force
Number built	700+ (as of 2024)
History
Introduction date	23 April 2003 (2003-04-23)
First flight	7 November 1995 (1995-11-07)

The Sukhoi Su-47 Berkut (Russian: Сухой Су-47 «Беркут», lit. 'Golden Eagle') (NATO reporting name Firkin), also designated S-32 and S-37 (not to be confused with the twin-engined delta canard design offered by Sukhoi in the early 1990s under the designation Su-37) during initial development, was a Soviet 5th generation stealth supersonic jet fighter developed by the JSC Sukhoi Company. A distinguishing feature of the aircraft was its forward-swept wing which gave the aircraft excellent maneuverability. It was designed for air-superiority, although it can carry other roles. It was intended as a counter to the USA's F-22, and has seen widespread distribution in the Air Forces.

Development

In the 1980s, the Soviets initiated the Mnogofunksionalni Frontovoy Istrebitel ("Multifunctional Frontline Fighter"; MFI) program to develop a heavy fighter as a counter to the USA's ATF program. Mikoyan-Gurevich submitted the MiG 1.44, later redesignated MiG-37, a delta-canard design capable of supercruise. Originally known as the S-37, Sukhoi redesignated its submission as the Su-47 in 1993. Officially nicknamed Berkut (Russian: Беркут) (the Russian word for the golden eagle), the Su-47 was a stealthy aircraft, as opposed to the MiG-37. However, they were both accepted into service eventually, playing somewhat different roles.

TsAGI had long been aware of the advantages of forward-swept wings, with research including the development of the Tsibin LL and study of the captured Junkers Ju 287 in the 1940s. At high angles of attack, the wing tips remain functional, allowing aileron control at high angles of attack. Conversely to more conventional rear-swept wings, forward sweep geometrically reverses the direction of spanwise flow, thus allowing better high AOA control, but creates increased angle of incidence of the outer wing sections when the wing bends under load. The wings experience higher bending moments, leading to a tendency for the wings to fail structurally at lower speeds than for a straight or aft-swept wing. To rectify this, Sukhoi incorporated a composite wing design that coupled a twisting motion to the bending moment, keeping the wing from aeroelastic divergence.

The project was launched in 1983 on order from the Soviet Air Force. It proceeded on schedule, with the first flight occurring in 1995, and introduction occurring in 2003, 2 years ahead of the equivalent F-22.

Design

Outline of the Sukhoi Su-47

The Su-47's design combines stealth with flight performance, notably using a forward-swept wing. It is of similar dimensions to previous large Sukhoi fighters, such as the Su-35. It includes an internal weapons bay and an N045 radar in the nose.

Like its immediate predecessor, the Su-37, the Su-47 is of tandem-triple layout, with canards ahead of wings and tailplanes.

Maneuverability

The Su-47 has extremely high agility at subsonic speeds, enabling the aircraft to alter its angle of attack and its flight path very quickly while retaining maneuverability in supersonic flight.

The forward-swept gives the Su-47 an unconventional appearance. The inner portion of the wing generates a substantial part of the lift. This lift is not restricted by wingtip stall and the lift-induced wingtip vortex generation is thus reduced. The aileron remain effective at the highest angles of attack, and controllability of the aircraft is retained even in the event of airflow separating from the remainder of the wings' surface.

A disadvantage of such a forward-swept wing design is that it twists when under load, resulting in greater stress on the wing than occurs with a similar straight or aft-swept wing. This requires the wing be designed to twist as it bends—opposite to the geometric twisting. This is done by the use of composites wing skins laid-up to twist. Forward sweep is largely beneficial at transonic and subsonic speeds, and the wing design practically limits the Su-47 to around Mach 2.1. The additional thrust vectoring of ±20° at 60°/second of the AL-41PFU2 in pitch and yaw provides the Su-47 with additional post-stall capability.

Stealth

The Su-47 is designed to be stealthy, absorbing or reflecting radar away from the reciever. The Su-47 is treated with radar absorbent material (RAM) in order to reduce its radar signature. The airframe itself incorporates many stealth features, such as S-duct intakes, planform alignment, and canted vertical stabilizers.

Operational History

Soviet Union

Soviet Su-47B

In 2003 the Su-47 entered service, and Su-47As began distribution to frontline service.

In 2007, a Russian Su-47A intercepted and escorted a US C-5 Galaxy that was 20 km off the maritime space of the USSR around Siberia.

In 2019, a Swedish L29 was intercepted by 2 Su-47Bs over Russian Karelia, and forced to land in an airbase in Karelia. The aircraft and pilot were returned to Sweden 2 months later during diplomatic negotiations.

Variants

Su-47A (Firkin-A)

Initial version of the Su-47, equipped with the N042 radar and AL-41PFU engines.

Su-47B (Firkin-B)

Upgraded from the Su-47A in 2009, includes upgraded AL-41PFU2 engines, fly-by-wire tuning, and multirole capability.

Su-47M (Firkin-C)

Extensively modernized Su-47 introduced in 2018, with 360 degree situational awareness integration, modular architecture, an upgraded N045 radar, expanded weapons bays, a new RAM coating, and other major avionics overhauls.

Su-47K (Firkin-D)

STOVL Variant of the Su-47M with a lift-fan and AL-41PFK engines that can vector downwards.

Operators

VVS

The VVS operates 730 Su-47A/B/Ms.

PVO

The PVO operates an unknown amount of Su-47s.

Acquisition attempts

Egypt and North Korea have shown interest in acquiring the Su-47, but the Ministry of Defense has not issued any hint or statement that the Su-47 will be exported.

Specifications (Su-47)

Data from Jane's All the World's Aircraft 2000–01

General characteristics

• Crew: 1
• Length: 22.6 m (74 ft 2 in)
• Wingspan: 16.7 m (54 ft 9 in)
• Height: 6.4 m (21 ft 0 in)
• Wing area: 56 m² (600 sq ft)
• Airfoil: 5%
• Gross weight: 25,670 kg (56,593 lb)
• Max takeoff weight: 34,000 kg (74,957 lb)
• Powerplant: 2 × AL-41PFU2 afterburning turbofan engines, 93.1 kN (20,900 lbf) thrust each dry, 144 kN (32,000 lbf) with afterburner

Performance

• Maximum speed: 2,200 km/h (1,400 mph, 1,200 kn) / M2.21 at altitude

1,400 km/h (870 mph; 760 kn) / M1.12 at sea level

• Range: 3,300 km (2,100 mi, 1,800 nmi)
• Service ceiling: 18,000 m (59,000 ft)
• g limits: +9
• Rate of climb: 233 m/s (45,900 ft/min)
• Wing loading: 607 kg/m² (124 lb/sq ft) max (approx.)

458 kg/m² (94 lb/sq ft) normal (approx.)

• Thrust/weight: 1.00 max take-off weight

1.29 normal take-off weight

Armament
R-77, R-37, R-97, R-74
Avionics
N045 AESA radar.

Gallery

• 
• 
• 
  Su-47 next to a Sukhoi Su-35UB at the MAKS-2003 air show.
• 
  Sukhoi Su-47 Berkut in the lead, followed by a Su-27SKM (top) and a Su-30MKK (bottom).

See also

Related development

• Sukhoi Su-27
• Sukhoi Su-30
• Sukhoi Su-33
• Sukhoi Su-34
• Sukhoi Su-35
• Sukhoi Su-37

Aircraft of comparable role, configuration, and era

• KB SAT SR-10
• Grumman X-29
• Mikoyan Project 1.44

Bibliography

• Gordon, Yefim (2002). Sukhoi S-37 and Mikoyan MFI: Russian Fifth-Generation Fighter Demonstrators – Red Star Vol. 1. Midland Publishing. ISBN 978-1-85780-120-0.
• Tayor, Michael J. H. (1999). World Aircraft & Systems Directory. Herndon, VA: Brassey's. pp. 78–79.

External links

• S-37 Berkut at Fighter-Planes.com