Sukhoi Su-37

Sukhoi Design Bureau

Industry	Aerospace, defense
Founded	1939
Founder	Pavel Sukhoi
Headquarters	Moscow , Russia
Products	Military aircraft, including Su-27 family fighters

Not to be confused with the S-37 Berkut (Su-47) forward-swept wing prototype.

The Sukhoi Su-37 (Russian: Сухой Су-37; NATO reporting name: Flanker-F; commonly referred to as the "Terminator") was a single-seat, twin-engine fighter developed by the Sukhoi Design Bureau as a technology demonstrator. It was created to improve pilot handling over the Su-27M (later designated Su-35), itself an advanced iteration of the Su-27. The only unit produced originated as the eleventh Su-27M airframe (T10M-11), constructed by the Komsomolsk-on-Amur Aircraft Production Association, before being equipped with thrust-vectoring exhaust nozzles and upgraded flight and weapons control systems. Its inaugural flight occurred in April 1996. Throughout its testing phase, the Su-37 showcased exceptional supermaneuverability at various air displays, executing complex moves such as the 360-degree somersault. The prototype was lost in a structural failure accident in December 2002. Despite reports in 1998 suggesting a second Su-37 had been assembled using the twelfth Su-27M frame, T10M-11 remained the sole prototype produced. Instead of mass production, Sukhoi integrated many of the Su-37’s advanced systems into other fighter platforms developed by the bureau.

Design and development

File:SukHoi-37.jpg

Front view of the aircraft

Research into thrust vectoring began at the Sukhoi Design Bureau in 1983, following a Soviet government directive to develop an enhanced version of the Su-27M. Under General Director Mikhail Simonov, who had led the original Su-27 design, Sukhoi collaborated with the Siberian Aeronautical Research Institute to explore axisymmetric thrust vectoring nozzles — a different approach compared to Western focus on two-dimensional nozzles. Concurrently, Lyulka (later known as UEC Saturn) initiated investigations into thrust-vectoring engines in 1985. By the late 1980s, Sukhoi had begun validating this research through testbed aircraft.

During flight trials of early Su-27Ms starting in 1988, it became apparent that pilots struggled to maintain control at high angles of attack due to limited effectiveness of conventional flight controls at low speeds. To address this challenge, engineers fitted thrust-vectoring engines onto the eleventh Su-27 airframe (T10M-11), which had been manufactured by the Komsomolsk-on-Amur Aircraft Production Association in Russia's Far East and initially served as a radar test platform. After completing the airframe in early 1995, it was transferred to Sukhoi’s experimental facility near Moscow for installation of vectoring nozzles. Although originally intended to be powered by the Lyulka-Saturn AL-37FU engine, which was not yet certified for flight, the aircraft was temporarily equipped with less powerful AL-31FP engines—AL-31F variants fitted with AL-100 vectoring nozzles from the AL-37FU. The plane was unveiled in May and replaced with AL-37FUs two months later; these engines allowed nozzle deflections of up to 15 degrees along the pitch axis either simultaneously or independently.

Aside from incorporating thrust-vectoring nozzles, externally the Su-37 closely resembled the canard-equipped Su-27M variant. The primary advancements were concentrated in avionics upgrades. Unlike prior Su-27Ms that utilized analog fly-by-wire systems, the Su-37 featured a fully digital flight control system integrated directly with its thrust vectoring mechanism. Coupled with its high thrust-to-weight ratio and full authority digital engine control technology, these integrated systems greatly enhanced maneuverability at elevated angles of attack and reduced speeds. Its weapons control suite included an upgraded N011M Bars pulse-Doppler phased-array radar capable of simultaneous air-to-air and air-to-ground operations. This radar could track up to twenty airborne targets while engaging eight concurrently—an improvement over the baseline N011 radar on earlier models that tracked fifteen targets and engaged six simultaneously. The aircraft also retained from the Su-27M a rear-facing N012 self-defense radar housed within its tail boom.

Significant cockpit enhancements were implemented as well. In addition to a head-up display (HUD), four color multi-function liquid crystal displays arranged in a "T" layout replaced older monochrome cathode-ray tube screens found on previous models. These provided comprehensive data on navigation, system status, and weapon selection. The pilot’s seat was reclined at a thirty-degree angle to improve tolerance against g-forces during intense maneuvers.

The aircraft sported a disruptive camouflage pattern composed of sand and brown colors and initially carried the code 711 Blue, later changed to 711 White. After completing ground testing at the Gromov Flight Research Institute, its maiden sortie took place on April 2, 1996 from Zhukovsky Airfield near Moscow with pilot Yevgeni Frolov at the controls. During its first five flights, nozzle deflections remained fixed. Due to insufficient funding from Russian military sources, Sukhoi financed development internally by allocating proceeds from exports of earlier Su-27s sold to China and Vietnam. The aircraft was publicly revealed later that year at Zhukovsky and officially redesignated as the Su-37.

Operational history

During the subsequent flight testing phase, the Su-37's enhanced agility, attributed to its thrust-vectoring control system, became evident. Simonov noted that this capability would enable pilots to devise innovative combat maneuvers and tactics, significantly improving performance in close-range aerial engagements. One such maneuver, the Super Cobra—a variation of the Pugachev's Cobra—was showcased during the aircraft’s international premiere at the Farnborough Airshow in September 1996. Under Frolov’s control, the aircraft executed a 180-degree pitch-up, briefly maintaining a tail-first orientation, theoretically allowing missile engagement of an adversary. This maneuver later evolved into the kulbit or somersault, where the Su-37 completed a full 360-degree loop with a turning radius roughly equal to the aircraft's length. Test pilot Anatoly Kvochur highlighted that thrust vectoring would provide a substantial advantage in close dogfights. However, some critics questioned the practical utility of these maneuvers; while enabling early missile lock-on, they also caused rapid kinetic energy depletion, potentially leaving the aircraft vulnerable if the initial attack failed.

The Su-37 was presented at the Paris Air Show in 1997. Although it performed only on the final day, event organizers recognized it as the highlight of the exhibition. Subsequently, the aircraft took part in several other air shows including Moscow's MAKS (air show), Dubai's International Defence Exhibition, and Santiago's FIDAE air show, as part of efforts to promote exports. Upon reaching the end of its engines’ operational lifespan, the original AL-37FUs were replaced with standard AL-31F engines lacking thrust-vectoring nozzles. To compensate for this loss, enhancements were made to the fly-by-wire flight control system. Additionally, foreign avionics components were substituted with domestically developed systems. Testing resumed in October 2000.

The flight test program concluded on 19 December 2002 when structural failure occurred during a high-g maneuver near Shatura, close to Moscow. The port tailplane detached due to cumulative stress exceeding design limits over six years of testing, causing a crash. Pilot Yuri Vashuk ejected safely. Despite participation in fighter procurement competitions in Brazil and South Korea, the Su-37 did not secure any export orders. In the mid-1990s, India funded development leading to the Su-30MKI, a two-seat fighter incorporating canards, N011M radar, and thrust-vectoring technologies evaluated on the Su-37. Moreover, tests on both the Su-27M and Su-37 demonstrated that thrust vectoring could compensate for maneuverability losses caused by removing canards, which added weight penalties to the airframe. The upgraded Su-35 model omitted canards entirely and first flew in February 2008; it featured advanced flight control systems similar to those used on experimental platforms and retained options for thrust vectoring.

Prominent media appearances

Main article: Aircraft in fiction § Sukhoi Su-27 and derivatives

External links

• Information on the Su-37 at EnemyForces.com
• Analysis of the Su-37 on Russian Military Analysis