https://en.wikipedia.org/wiki/Sukhoi_Su-47
The Sukhoi Su-47 Berkut (Russian: ????? ??-47 ??????, 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 an experimental
supersonic jet fighter developed by Sukhoi Aviation Corporation. A
distinguishing feature of the aircraft was its forward-swept wing that gave the
aircraft excellent agility and maneuverability. While serial production of the
type never materialized, 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-35BM and current fifth-generation jet fighter Sukhoi
Su-57.
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.
Though similar in overall concept to the Grumman X-29 research aircraft of the
1980s, the Su-47 is larger and far closer to an actual combat aircraft than its
US counterpart.
Like its immediate predecessor, the Su-37, the Su-47 is of tandem-triple layout,
with canards ahead of wings and tailplanes. Interestingly, the Su-47 has two
tailbooms of unequal length outboard of the exhaust nozzles. The shorter boom,
on the left-hand side, houses rear-facing radar, while the longer boom houses a
brake parachute.
Role
Experimental/Technology demonstrator
Manufacturer
Sukhoi
First flight
25 September 1997
Status
Cancelled
Primary user
Russian Air Force
Number built
1
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.
The swept-forward wing, compared to a swept-back wing of the same area, provides
a number of advantages:
* 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
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
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
by the use of composites wing skins laid-up to twist. The plane was initially
limited to Mach 1.6.
Specifications (Su-47)
General characteristics
Crew: 1
Length: 22.6 m (74 ft 2 in)
Wingspan: 15.16 m to 16.7 m (49 ft 9 in to 54 ft 9 in)
Height: 6.3 m (20 ft 8 in)
Empty weight: 16,375 kg (36,100 lbs)
Loaded weight: 25,000 kg (55,115 lb)
Max. takeoff weight: 35,000 kg (77,162 lb)
modification) turbofans Dry thrust: 83.4 kN (18,700 lbf) each
Thrust with afterburner: 142.2 kN (32,000 lbf) each
Performance
Maximum speed: Mach 1.65 (Achieved in test flights) (1,717 km/h, 1,066 mph)
At sea level: Mach 1.16 (1,400 km/h, 870 mph)
Range: 3,300 km (2,050 mi)
Service ceiling: 18,000 m (59,050 ft)
Rate of climb: 233 m/s (46,200 ft/min)
Thrust/weight: 1.16 (loaded) / 1.77 (empty)
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