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Sukhoi S-37 ``Berkut`` 5^th Generation Russian Fighter

A. Sukhoi S-37 “Berkut”, Russian’s 5^th generation fighter. New in Sukhoi fighters forward-swept wing design integrated into the tandem triplane configuration. Visible in the tail section of the aircraft are two “stringers”. A rather interesting element: the “stringers” are of different length. At first it might appear that this is an optical illusion, however, after a closer examination the difference in length of the “stringers” is obvious. It is reasonable to conclude that the longer “stringer” contains a spin-recovery parachute. However, the difference in size of the “stringers” can also be explained by a possibility of an aft facing radar.

B. The S-37 fighter is designed to use the thrust-vectoring AL-37FU engines, however, during the first test flights it was used the more powerful D-30F6 engines from MiG-31, Russia’s most advanced high-speed interceptor aircraft. The original, 1991 S-37 project was a smaller aircraft with a delta wing design and a single AL-41F engine. This apparently was not the case with the 1997 S-37 “Berkut”: the new aircraft is significantly larger, it is equipped with two engines, and employs a forward-swept wing design. The combined thrust of S-37’s engines is 25 tons.

C. The basic dimensions and weight of the S-37 “Berkut” are similar to those of Su-37. While the main advantage of the forward-swept wing design is the improved maneuverability at subsonic speeds and high angles of attack, its primary drawbacks are the reduced lift and handling problems at supersonic speeds. A natural way to counter such problems is by using more powerful engines and advanced thrust-vectoring controls. The 1991 S-37 project was designed with very powerful AL-41F engines in mind. The AL-441F would be able to satisfy the power requirements of the S-37.

D. The S-37 has large canards mounted on the intake side, close to the leading edge of the forward-swept wing. It is also apparent that the vertical stabilizers are canted slightly outward, and not inward. Two large auxiliary intake doors are located on the centre fuselage section. It previously suggested that the nose section of the S-37 was similar to the one of Su-27 family. However, later it became clear that it is rather similar to the original S-37 design announced in 1991 and later canceled. It is now clear that the S-37 fighter is intended to become Russia’s fifth generation fighter.

Main characteristics:

- 75 feet long

- inverted-arrow wing design

- two thrust-vectoring engines

- tandem triplane configuration

- reduced RCS airframe

- airframe is covered with radio wave absorbent.

Dimensions:

Wingspan 15.65m

Length 22.2m

Height 6.36m

Powerplant:

Two afterburning, thrust-vectoring Saturn/Lulka AL-37FU with digital controls;

Thrust (each): 83.35kN dry; 142.2kN with afterburning;

Thrust-vectoring in pitch -20* to 20* at 30* per second.

Weight:

Normal take-off 26000kg

MTOW 34000kg

Performance:

Max level speed at sea level 760kt (1400km/h)

Max rate of climb at sea level 230m/sec

Service ceiling 18800m

Range (armed, internal fuel) 3880km

Required runway length 1200m

Armament:

One GSh-30 30mm cannon with 150 rounds;

Two R-73 and two R-27 missiles carried under the fuselage on special conformal suspensions. There are no armaments under the wing, but as need be it can be placed on underwing pylons.