The Sukhoi Su-37 (NATO reporting name: 'Flanker-F') is a Russian experimental multi-role jet fighter aircraft. It is a single seat fighter modified from the 1st generation Su-35 prototypes for thrust vector control testing.
The Su-37 is not to be confused with the S-37 (Su-47) forward-swept wing technology demonstrator.
The Su-37 is derived from the first-generation Su-35, which was initially designated Su-27M. A Su-27M prototype (T-10S-70) first flew in 1988. Changes from the Su-27 include canards, upgraded engines, new radar, and a digital fly by wire flight control system. Sukhoi changed the Su-27M's designation to Su-35 in 1993. Later Su-35 prototypes added a glass cockpit and modified tailfins.
The Su-35 design was modified into the Su-37 by adding 2D thrust vectoring nozzles. The first Su-37 test aircraft made its maiden flight in April 1996 equipped with vectoring nozzles. The Su-37 appeared at the 1996 Farnborough airshow piloted by Sukhoi test pilot Yevgeny Frolov. A second Su-37 was similarly converted in 1998.
Su-37 never reached production stage; by mid-2000, Sukhoi introduced several modernizations of Su-27, such as Su-30MKI and 2nd generation Su-35/Su-35BM, which feature similar improvements such as improved avionics and radar systems, and thrust vectoring engines.
The Su-37 is a single-seat, all-weather fighter and ground attack prototype aircraft, derived from the Su-27. The Su-37 includes several updates over the Su-27, including all-weather multi-mode passive electronically scanned array radar with synthetic aperture, terrain avoidance, terrain mapping and a rear-facing radar. The airframe includes a percentage of parts made from composites, unlike the all-metal Su-27. Additionally, the Su-37 incorporates the AL-31FP engines equipped with thrust vectoring. The Su-37’s nozzles are variable in pitch and travel plus or minus 15 degrees, they can be operated differentially to provide a rolling moment.
In the cockpit the aircraft is the first Russian fighter with the Hands On Throttle and Stick, or HOTAS, system and the first with side-stick. The weapon system shares much with the Su-30"MK", but it lacks the large display in the rear cockpit occupied by the weapons system officer. The cockpit features four multi-function displays (MFDs) instead of traditional dial-type analogue instruments and has an ejection seat inclined 30 degrees backwards to help counter the effects of high g-forces. The two-grip flying control configuration was designed to prevent the pilot from flailing around when the aircraft engaged in fast vectored-thrust manoeuvres. Both the fixed throttle and the side-stick controller provide secure points for the pilot to brace his hands.
 Avionics and propulsion
The engine not only incorporates a new generation 3D TVC but also is tough and resistant to engine surge even during classic, inverted and flat spins, giving better reliability and maneuverability, such as when the angle of attack is as high as 180 degrees.
The Su-37 can carry air-to-air and air-to-surface weapons on 12 stations. The number of missiles and bombs carried can be increased to 14 with the use of multi-payload racks.
* Russian Air Force
 Specifications (Su-37)
Data from Gordon and Davison
* Crew: 1, pilot
* Length: 22.183 m (72 ft 9 in)
* Wingspan: 14.7 m (48 ft 3 in)
* Height: 6.43 m (21 ft 1 in)
* Wing area: 62.0 m² (667 ft²)
* Empty weight: 18,500 kg (40,790 lb)
* Max takeoff weight: 35,000 kg (77,160 lb)
* Powerplant: 2× Lyulka AL-31FP turbofans, 145 kN (32,000 lbf) each
* Maximum speed: Mach 2.5 (2,970 km/h at high altitude) (1,550 mph )
* Range: 3,700 km (2,230 mi)
* Service ceiling: 18,000 m (59,100 ft)
* 1 × 30 mm GSh-30 cannon with 150 rounds
* 12 × wing and fuselage stations for up to 8,200 kg (18,080 lb) of ordnance