Sukhoi Su-57

Sukhoi Su-57, single-seat, twin-engine Russian heavyweight multirole combat aircraft that first flew in 2010. It was developed by the Sukhoi design bureau, creator of the Flanker series, a line of aircraft that serves as the backbone of the Russian Aerospace Forces (VKS). The maximum takeoff weight of the Su-57 “Felon” is about 35 metric tons, and the top speed is Mach 2. Though the Su-57 is sometimes described as a “fifth generation” fighter, the generational terms used for fighter aircraft are somewhat vague.

Development

The Su-57 was developed after two (initially Soviet) proposals for new-generation fighters failed to reach the production stage: a canard-delta configuration developed by the Mikoyan design bureau and a forward-swept-wing canard design from Sukhoi. In 1999 Russia launched a combat aircraft initiative, the PAK FA (Russian: ПАК ФА; Perspektivnyi Aviatsionnyi Kompleks Frontovoi Aviatsyi, “Prospective Aviation Complex of Frontline Aviation”). This resulted in the selection of a new Sukhoi design that featured a cropped delta wing and twin tails. India was a partner country for the project from 2007 to 2018. The proposed variant was to be developed as the Fifth Generation Fighter Aircraft (FGFA) program; although India left this arrangement, it may order the Su-57 in the future.

As Russia’s most advanced fighter, the Sukhoi Su-57 has a smaller radar cross section than the Su-27 “Flanker,” helping the aircraft avoid detection by enemy defense systems. This is achieved through its airframe shape, choice of materials, and inclusion of an internal weapons bay. Carrying weapons internally also reduces drag, which aids supercruise, the ability to achieve and sustain a supersonic speed without recourse to afterburners.

Whether it offers a large enough jump in capability over the Sukhoi Su-35 “Flanker-E” (itself intended to fill the gap between legacy Flankers and Felons) to justify what is assumed to be a much higher cost remains to be seen. U.S. levels of low radar observability, which require aircraft to have immaculately smooth outer surfaces, are incompatible with the traditional Russian “rough-and-ready” doctrines. Instead, the design emphasizes high performance, supermaneuverability (extreme “post-stall” maneuverability), and a counter-stealth capability (using unique, low-band wing-root antennae).

Defensive measures and sensors

The Su-57 carries a comprehensive defensive suite, which includes missile approach warning (MAW) sensors. It is probably the first fighter aircraft fitted with a directed infrared countermeasures (DIRCM) system, a defensive aid that “blinds” hostile infrared missiles. (DIRCM is essentially a focused infrared light—it fires a beam directly into the seeker head of a threatening missile to transfix and neutralize it.) The Su-57 has two DIRCM 101KS-O sensors. In addition, the aircraft can use the infrared search-and-track ability of the passive (non-emitting) sensor 101KS-V (OLS-50M), which also features a laser range finder. As with all fighter aircraft, the Su-57 carries chaff (thin strips of radar-reflective material), to confuse hostile radars, and flares, to distract infrared-guided missiles. An L402 Himalayas active jammer is contained in the aircraft’s tail cone.

The main aircraft sensor is the N036 Belka (Russian: Белка, “Squirrel”), an active electronically scanned array (AESA) radar system developed by Tikhomirov Scientific Research Institute of Instrument Design (NIIP). It consists of a primary X-band (8–12 gigahertz) radar, called the N036-1-01, mounted on the nose. There are two smaller elliptical sideways-looking antenna arrays under hexagonal dielectric panels on the sides of the nose. Two long, thin L-band (1–2 gigahertz) N036L-1-01 antenna arrays are in the wing’s leading edge and the leading-edge vortex controller (LEVCON). The LEVCON is an innovative control surface used by the Su-57 and is visible on the inner sections of the wing’s leading edges; another distinctive feature of the Su-57 is the all-movable vertical tail fins.

Airframe, engines, and armament

Unlike the U.S. F-22 Raptor, which features side-by-side engines buried within the airframe and a flat underside, the Su-57 employs widely spaced engine nacelles that are similar to those of the Su-27. The aircraft is powered by two AL-41F turbofan engines, which are planned to be replaced with the more modern AL-51F1. For extreme maneuvers, the aircraft may steer with the use of 2.5D thrust vectoring nozzles. Although the aircraft is currently considered to have a large “un-stealthy” rear hemisphere radar signature, a flatter type of exhaust nozzle will likely be integrated later and should reduce this. Working in conjunction with a stealthy unmanned combat air vehicle (UCAV), such as Sukhoi’s S-70 Okhotnik (“Hunter”)-B, may provide a solution to some of the Su-57’s perceived shortcomings. The S-70 was designed in parallel with the Su-57 and shares some features and technologies.

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The Su-57 has 12 hard points for ordnance or stores, six internal and six external. The Su-57’s armament includes an internal 30-mm caliber 9-A1-4071K GSh-30-1 automatic cannon with 150 rounds. Weighing approximately 50 kg (110 pounds), this cannon is one of the lightest in its class and has a maximum theoretical rate of fire of 1,500 rounds per minute. The aircraft can be fitted with various guided air-to-air weapons, including the R-77M medium-range active radar-guided missile, R-74M2 infrared-guided missile, and R-37M long-range radar-guided missile. Air-to-surface missile options include the Kh-38 standoff missiles, Kh-35U anti-ship missiles, and Kh-31AD/PD and Kh-58 anti-radiation missiles to destroy radars. It is also compatible with the KAB series of guided bombs, including the large KAB-1500, which weighs approximately 1,500 kg (3,300 pounds).

Operational history

The Su-57 has yet to see large-scale introduction. About 30 production aircraft had been delivered to the Russian Aerospace Forces (VKS) by the start of 2025, with an expressed desire for a total of 76. The Su-57’s slow integration is partly because of the funding crisis in Russia caused by its aggression toward neighboring Ukraine (which Russia invaded in 2014 and expanded the invasion from 2022), technical issues with the project, and the adequacy of existing platforms such as the Su-35.

Its use in combat has been somewhat unclear. It was likely deployed briefly in Syria for operational testing, and its use in the invasion of Ukraine has been mostly limited to firing long-range missiles from within Russian airspace. Three Ukrainian one-way attack (OWA) drones damaged at least one Su-57 on the ground at the 929th VP Chkalova State Flight Test Centre in Akhtubinsk in 2024. No Su-57s have yet been exported, though Algeria has ordered it, and Vietnam may also receive some.