This article is about the aircraft at one time designated S-37. For the aircraft designated Su-37, see Sukhoi Su-37.
The Sukhoi Su-47 Berkut (Russian: Сухой Су-47 Беркут, lit. 'Golden Eagle') (NATO reporting nameFirkin[1]), also designated S-32 and S-37 (not to be confused with the twin-engined delta canard design[2] offered by Sukhoi in the early 1990s under the designation Su-37) during initial development, was an experimental supersonicjet fighter developed by the JSC Sukhoi Company. A distinguishing feature of the aircraft was its forward-swept wing[3] that gave the aircraft excellent agility and maneuverability. While serial production of the type never materialized and the configuration was not further pursued, the sole aircraft produced served as a technology demonstrator prototype for a number of advanced technologies later used in the 4.5 generation fighter Su-35 and current fifth-generation jet fighterSu-57.
Originally known as the S-37, Sukhoi redesignated its advanced test aircraft as the Su-47 in 2002. Officially nicknamed Berkut (Russian: Беркут) (the Russian word for the golden eagle), the Su-47 was originally built as Russia's principal testbed for composite materials and sophisticated fly-by-wire control systems, as well as new airframe technologies.
TsAGI has 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 retracted allowing the aircraft to retain aileron control. Conversely to more conventional rear-swept wings, forward sweep geometrically 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.
The project was launched in 1983 on order from the Soviet Air Force. But when the USSR dissolved, funding was frozen and development continued only through funding by Sukhoi.[citation needed] Like its US counterpart, the Grumman X-29, the Su-47 was primarily a technology demonstrator for future Russian fighters such as the Sukhoi Su-57. The forward-swept wing configuration was ultimately not pursued because it was mainly advantageous at transonic speeds while an aft-swept wing was superior at supersonic speeds.[4]
Design
Outline of the Sukhoi Su-47
The Su-47 is of similar dimensions to previous large Sukhoi fighters, such as the Su-35. To reduce development costs, the Su-47 borrowed the forward fuselage, vertical tails, and landing gear of the Su-27 family. Nonetheless, the aircraft includes an internal weapons bay, and space set aside for an advanced radar.
Like its immediate predecessor, the Su-37, the Su-47 is of tandem-triple layout, with canards ahead of wings and tailplanes. The Su-47 has two tailbooms of unequal length outboard of the exhaust nozzles. The shorter boom, on the left-hand side, houses ECM system, while the longer boom houses a rear-facing radar.
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 Su-47 has a maximum speed of Mach 1.6 at high altitudes and a 9g capability.[5][unreliable source?]
The swept-forward wing, compared to a swept-back wing of the same area, provides a number of advantages:[5][unreliable source?]
higher lift-to-drag ratio
better agility in dogfight situations
higher range at subsonic speed
improved stall resistance and anti-spin characteristics
improved stability at high angles of attack
a lower minimum flight speed
a shorter take-off and landing distance
Wings
The forward-swept midwing gives the Su-47 its unconventional appearance. A substantial part of the lift generated by the forward-swept wing occurs at the inner portion of the wingspan. This inboard lift is not restricted by wingtip stall and the lift-induced wingtip vortex generation is thus reduced. The ailerons—the wing's control surfaces—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 downside of such a forward-swept wing design is that it geometrically produces wing twisting as it bends under load, resulting in greater stress on the wing than for 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. The plane was initially limited to Mach 1.6. Because the forward sweep was primarily beneficial at transonic speed while losing out to aft-swept wing at supersonic speed, it was not further pursued.
Thrust vectoring
The thrust vectoring (with PFU engine modification) of ±20° at 30°/second in pitch and yaw will greatly support the agility gained by other aspects of the design.
Specifications (Su-47)
Data from Jane's All the World's Aircraft 2000–01[6]
^Buttler, Tony and Gordon, Yefim. "Soviet Secret Projects: Fighters Since 1945". Midland Publishing, 2005. ISBN1-85780-221-7.
^Russian Aviation Page: Sukhoi S-37 Berkut (S-32) February 13, 2006, at the Wayback Machine
^Butowski, Piotr (2021). Su-57 Felon. Stamford, UK: Key Books. p. 13. ISBN978-1-913870-44-7.
^ abSu-47 (S-37 Berkut) Experimental Fighter Aircraft – Air Force Technology
^Jackson, Paul, ed. (2000). Jane's All the World's Aircraft 2000–01 (91st ed.). Coulsdon, Surrey, United Kingdom: Jane's Information Group. pp. 457–458. ISBN978-0710620118.
^"Су-47 (С-37) "Беркут" (Russian)". testpilot.ru. Retrieved 29 August 2020.
^"Su-47 (S-37 Berkut) Golden Eagle Fighter". airforce-technology.com. Retrieved 25 March 2020.
Bibliography
Gordon, Yefim (2002). Sukhoi S-37 and Mikoyan MFI: Russian Fifth-Generation Fighter Demonstrators – Red Star Vol. 1. Midland Publishing. ISBN978-1-85780-120-0.
Tayor, Michael J. H. (1999). World Aircraft & Systems Directory. Herndon, VA: Brassey's. pp. 78–79.
External links
Wikimedia Commons has media related to Sukhoi Su-47.
S-37 Berkut at Fighter-Planes.com
February 20, 2023
sukhoi, this, article, about, aircraft, time, designated, aircraft, designated, sukhoi, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, remo. This article is about the aircraft at one time designated S 37 For the aircraft designated Su 37 see Sukhoi Su 37 This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Sukhoi Su 47 news newspapers books scholar JSTOR July 2009 Learn how and when to remove this template message The Sukhoi Su 47 Berkut Russian Suhoj Su 47 Berkut lit Golden Eagle NATO reporting name Firkin 1 also designated S 32 and S 37 not to be confused with the twin engined delta canard design 2 offered by Sukhoi in the early 1990s under the designation Su 37 during initial development was an experimental supersonic jet fighter developed by the JSC Sukhoi Company A distinguishing feature of the aircraft was its forward swept wing 3 that gave the aircraft excellent agility and maneuverability While serial production of the type never materialized and the configuration was not further pursued the sole aircraft produced served as a technology demonstrator prototype for a number of advanced technologies later used in the 4 5 generation fighter Su 35 and current fifth generation jet fighter Su 57 Su 47 BerkutThe only Su 47 at an airshow in 2008 Role Experimental aircraft Technology demonstratorManufacturer SukhoiDesigner Mikhail PogosyanFirst flight 25 September 1997Status CancelledPrimary user Russian Air ForceNumber built 1Developed from Sukhoi Su 37 Contents 1 Development 2 Design 2 1 Maneuverability 2 2 Wings 2 3 Thrust vectoring 3 Specifications Su 47 4 Gallery 5 See also 6 References 7 Bibliography 8 External linksDevelopment EditOriginally known as the S 37 Sukhoi redesignated its advanced test aircraft as the Su 47 in 2002 Officially nicknamed Berkut Russian Berkut the Russian word for the golden eagle the Su 47 was originally built as Russia s principal testbed for composite materials and sophisticated fly by wire control systems as well as new airframe technologies TsAGI has 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 retracted allowing the aircraft to retain aileron control Conversely to more conventional rear swept wings forward sweep geometrically 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 The project was launched in 1983 on order from the Soviet Air Force But when the USSR dissolved funding was frozen and development continued only through funding by Sukhoi citation needed Like its US counterpart the Grumman X 29 the Su 47 was primarily a technology demonstrator for future Russian fighters such as the Sukhoi Su 57 The forward swept wing configuration was ultimately not pursued because it was mainly advantageous at transonic speeds while an aft swept wing was superior at supersonic speeds 4 Design Edit Outline of the Sukhoi Su 47 The Su 47 is of similar dimensions to previous large Sukhoi fighters such as the Su 35 To reduce development costs the Su 47 borrowed the forward fuselage vertical tails and landing gear of the Su 27 family Nonetheless the aircraft includes an internal weapons bay and space set aside for an advanced radar Like its immediate predecessor the Su 37 the Su 47 is of tandem triple layout with canards ahead of wings and tailplanes The Su 47 has two tailbooms of unequal length outboard of the exhaust nozzles The shorter boom on the left hand side houses ECM system while the longer boom houses a rear facing radar Maneuverability Edit 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 Su 47 has a maximum speed of Mach 1 6 at high altitudes and a 9g capability 5 unreliable source The swept forward wing compared to a swept back wing of the same area provides a number of advantages 5 unreliable source higher lift to drag ratio better agility in dogfight situations higher range at subsonic speed improved stall resistance and anti spin characteristics improved stability at high angles of attack a lower minimum flight speed a shorter take off and landing distanceWings Edit The forward swept midwing gives the Su 47 its unconventional appearance A substantial part of the lift generated by the forward swept wing occurs at the inner portion of the wingspan This inboard lift is not restricted by wingtip stall and the lift induced wingtip vortex generation is thus reduced The ailerons the wing s control surfaces 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 downside of such a forward swept wing design is that it geometrically produces wing twisting as it bends under load resulting in greater stress on the wing than for 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 The plane was initially limited to Mach 1 6 Because the forward sweep was primarily beneficial at transonic speed while losing out to aft swept wing at supersonic speed it was not further pursued Thrust vectoring Edit The thrust vectoring with PFU engine modification of 20 at 30 second in pitch and yaw will greatly support the agility gained by other aspects of the design Specifications Su 47 EditData from Jane s All the World s Aircraft 2000 01 6 General characteristicsCrew 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 Soloviev D 30F6 7 afterburning turbofan engines 93 1 kN 20 900 lbf thrust each engines with 2 dimensional and 3 dimensional thrust vectoring nozzles planned for testing dry 153 kN 34 000 lbf with afterburnerPerformance Maximum speed 2 200 km h 1 400 mph 1 200 kn M2 21 at altitude1 400 km h 870 mph 760 kn M1 12 at sea level dd dd dd 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 8 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 dd dd dd Thrust weight 0 92 max take off weight1 21 normal take off weight dd dd dd Armament provision for conformal weapon storageAvionics provision for mission radar in nose and ECM in tail radomesGallery Edit 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 Edit Aviation portalRelated development Sukhoi Su 27 Sukhoi Su 30 Sukhoi Su 33 Sukhoi Su 34 Sukhoi Su 35 Sukhoi Su 37 Sukhoi Su 57 Sukhoi HAL FGFAAircraft of comparable role configuration and era KB SAT SR 10 Grumman X 29 Mikoyan Project 1 44References Edit Su 47 S 37 Berkut www globalsecurity org Retrieved 2016 01 10 Buttler Tony and Gordon Yefim Soviet Secret Projects Fighters Since 1945 Midland Publishing 2005 ISBN 1 85780 221 7 Russian Aviation Page Sukhoi S 37 Berkut S 32 Archived February 13 2006 at the Wayback Machine Butowski Piotr 2021 Su 57 Felon Stamford UK Key Books p 13 ISBN 978 1 913870 44 7 a b Su 47 S 37 Berkut Experimental Fighter Aircraft Air Force Technology Jackson Paul ed 2000 Jane s All the World s Aircraft 2000 01 91st ed Coulsdon Surrey United Kingdom Jane s Information Group pp 457 458 ISBN 978 0710620118 Su 47 S 37 Berkut Russian testpilot ru Retrieved 29 August 2020 Su 47 S 37 Berkut Golden Eagle Fighter airforce technology com Retrieved 25 March 2020 Bibliography EditGordon 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 amp Systems Directory Herndon VA Brassey s pp 78 79 External links Edit Wikimedia Commons has media related to Sukhoi Su 47 S 37 Berkut at Fighter Planes com Retrieved from https en wikipedia org w index php title Sukhoi Su 47 amp oldid 1135446919, wikipedia, wiki, book, books, library,
