| Su-37 | |
|---|---|
 | |
| General information | |
| Type | Air superiority fighterTechnology demonstrator |
| National origin | Russia |
| Designer | Sukhoi Design Bureau |
| Built by | Komsomolsk-on-Amur Aircraft Production Association |
| Status | Out of service and production, prototype, crashed in 2002 |
| Number built | 1[1] |
| History | |
| Introduction date | 25 October 1997 |
| First flight | 2 April 1996; 29 years ago (1996-04-02) |
| Developed into | Sukhoi Su-30MKI (India) Sukhoi Su-30MKM (Malaysia) Sukhoi Su-30SM (Russia) Sukhoi Su-35 (Russia and China) |
TheSukhoi Su-37 (Russian:Сухой Су-37;NATO reporting name:Flanker-F; popularly nicknamed "Terminator"[2]) was a single-seat twin-engine aircraft designed by theSukhoi Design Bureau which served as atechnology demonstrator. It met the need to enhance pilot control of theSu-27M (later renamed Su-35), a further development of theSu-27. The sole example built was originally the eleventh Su-27M (T10M-11) built by theKomsomolsk-on-Amur Aircraft Production Association before havingthrust-vectoring nozzles installed. It also had updated flight- and weapons-control systems. The aircraft made itsmaiden flight in April 1996. Throughout the flight-test program, the Su-37 demonstrated itssupermanoeuvrability at air shows, performing manoeuvres such as a360-degree somersault. The aircraft crashed in December 2002 due to structural failure. The Su-37 did not enter production, despite a report in 1998 which claimed that Sukhoi had built a second Su-37 using the twelfth Su-27M airframe,[3] T10M-11 remained the sole prototype. Sukhoi had instead applied the aircraft's systems to the design bureau's other fighter designs.
The Sukhoi Design Bureau started research on thrust vectoring in 1983,[4] when the Soviet government tasked the bureau with the separate development of the Su-27M.[5] At the insistence of General DirectorMikhail Simonov, who had been the chief designer of the Su-27, Sukhoi and theSiberian Aeronautical Research Institute studiedaxisymmetrical vectoring nozzles. This was in contrast to the focus on two-dimensional nozzles prevailing in the West.Lyulka (laterLyulka-Saturn) also began studies of thrust-vectoring engines in 1985.[6] By the late 1980s, Sukhoi were evaluating their research using its flying test beds.[7]
During test flights of the Su-27Ms, which began in 1988, engineers discovered that pilots failed to maintain active control of the aircraft at highangles of attack due to the ineffectiveness offlight control surfaces at low speeds. Engineers therefore installed thrust-vectoring engines to the eleventh Su-27 (factory code T10M-11), which had been built by theKomsomolsk-on-Amur Aircraft Production Association in thecountry's Far East and was being used as a radar test bed.[8] Following the airframe's completion in early 1995, the aircraft was delivered to the design bureau's experimental plant near Moscow, where engineers started installing the nozzles on the aircraft.[9][N 1] Although Sukhoi had intended the Lyulka-Saturn AL-37FU to power the aircraft, the engine had not yet been flight-cleared. The aircraft was temporarily fitted with the less-powerful AL-31FP engine, essentially an AL-31F engine that had the AL-100 vectoring nozzles of the AL-37FU.[9] The aircraft was rolled out in May.[11] Two months later, the temporary engines were replaced with AL-37FUs; its nozzles could only deflect 15 degrees up or down in thepitch axis, together or differentially.[12]
Apart from the addition of thrust-vectoring nozzles, the Su-37 did not outwardly differ much from the canard-equipped Su-27M. Instead, engineers had focused on the aircraft's avionics. Unlike previous Su-27Ms, the Su-37 had a digital (as opposed to analogue)fly-by-wireflight control system, which was directly linked to the thrust-vectoring control system.[13] Together with the aircraft's overall highthrust-to-weight ratio and the engine'sfull authority digital engine control feature, the integrated propulsion and flight control systems added maneuverability at high angles of attack and low speeds.[14] The aircraft'sweapons-control system had also been improved, as it included anN011M Bars (literally "Panther")pulse-Dopplerphased-array radar that provided the aircraft with simultaneous air-to-air and air-to-ground capability. The radar was capable of tracking twenty aerial targets and directing missiles toward eight of them simultaneously; in comparison, the Su-27M's baseline N011 could only track fifteen aerial targets and engage six of them simultaneously.[15][16] The aircraft retained from the Su-27M the N012 self-defence radar located in the rearward-projecting tail boom.[7]
Considerable improvement had also been made to the cockpit layout. In addition to thehead-up display, the Su-37 had fourSextant Avioniquemulti-function colourliquid crystal displays arranged in a "T" configuration; they had better backlight protection than the Su-27M's monochromecathode-ray tube displays. The displays presented to the pilot information about navigation, systems status, and weapons selection. The pilot sat on anejection seat that was reclined to 30 degrees to improveg-force tolerance.[7][17]
Painted in a disruptive sand and brown scheme, the aircraft was given the code711 Blue, later changed to711 White.[17] Following ground checks at theGromov Flight Research Institute, the aircraft made itsmaiden flight on 2 April 1996 fromZhukovsky Airfield outside Moscow, piloted byYevgeni Frolov. The nozzles were fixed during the first five flights.[16][N 2] Due to the lack of funding from theRussian Air Force, Sukhoi was compelled to finance the project with its own funds; according to Simonov, the company channelled revenue from the exports of the Su-27s to China and Vietnam towards the project.[7][18] The aircraft was publicly unveiled at Zhukovsky later in the year, and was redesignated Su-37.[16]
During the subsequent flight-test programme, the Su-37's supermaneuverability as a result of thrust-vectoring controls became apparent. According to Simonov, such a feature would allow pilots to develop new combat manoeuvres and tactics, greatly enhancing its effectiveness in dogfights.[19] Among the new manoeuvres was the Super Cobra, which was a variation of thePugachev's Cobra and was demonstrated during the aircraft's international debut at theFarnborough Airshow in September 1996. Piloted by Frolov, the aircraft pitched up 180 degrees and maintained the tail-first position momentarily, which would theoretically allow the aircraft to fire a missile at a combat opponent.[16] The Super Cobra evolved into thekulbit (somersault), in which the Su-37 performed a 360-degree loop with an extremely tight turning radius the length of the aircraft.[20] According to test pilotAnatoly Kvochur, thrust vectoring would have given the aircraft a considerable advantage in close-indogfights.[21] Nonetheless, critics have questioned the practical benefits of such manoeuvres; although they would allow an earlymissile lock-on, it would come at the expense of a rapid loss ofkinetic energy, which would leave the aircraft vulnerable when pilots missed their first shot.[22]
The aircraft was demonstrated at theParis Air Show in 1997. Although it was only able to perform on the last day of the show, the organisers recognised the Su-37 as the standout performer at the event.[23] The aircraft thereafter participated in theMAKS air show in Moscow, theInternational Defence Exhibition in Dubai, and theFIDAE air show inSantiago, Chile, as authorities sought to export the aircraft.[24] With the expiration of the engines' service lives, the aircraft had the AL-37FUs replaced with standard production AL-31F engines which lacked movable nozzles. The loss of thrust vectoring was partially mitigated by an update to the fly-by-wire flight control system. The aircraft's foreign avionics were also replaced with indigenous designs. It resumed test flights in October 2000.[25]
The flight-test programme ended on 19 December 2002 when the aircraft's porttailplane broke off during a high-g manoeuvre, leading to it crashing atShatura, near Moscow. The structural failure was caused by repeated exceeding of the aircraft'sdesign load during six years of testing.[26] The pilot Yuri Vashuk ejected safely.[27][28] Despite the entry of the Su-37 into Brazilian andSouth Korean fighter tenders, the aircraft failed to gain any foreign customers. India in the mid-1990s funded the development of what would result in theSu-30MKI, which is a two-seat fighter design that incorporated the canards, N011M radar and thrust-vectoring technology that were present and evaluated on the Su-37.[29] In addition, through tests of the Su-27M and the Su-37, engineers had determined that thrust vectoring could compensate for the loss of manoeuvrability brought about by the removal of canards, the design of which imposed a weight penalty on the airframe.[30] The modernized Su-35, without canards,[31] made its first flight in February 2008.[32]
Data from Gordon,[33] Novichkov[13]
General characteristics
Performance
Armament
Avionics
Related development
Aircraft of comparable role, configuration, and era
Related lists
This was popularly termed 'Su-37 Terminator' ...
