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Russia’s Su-57 Stealth Fighter Jet Reaches Key 5th-Gen Milestone with New Product 177 Engine Test.
Russia’s Rostec has confirmed the first flight of the Su-57 equipped with the new Product 177 engine, marking the start of dedicated flight testing. The milestone matters because propulsion performance is central to whether the aircraft can fully meet fifth-generation expectations for range, speed, and combat persistence.
On December 22, 2025, the Russian state corporation Rostec announced that the Su-57 fifth-generation fighter successfully completed its first flight equipped with the new “Product 177” engine, marking a significant milestone in the ongoing development of Russia’s most advanced combat aircraft. This announcement, published on Rostec’s official website, signals the transition from bench and ground testing to a dedicated joint flight-test campaign led by the United Aircraft Corporation (UAC) and United Engine Corporation (UEC). At a time when fifth-generation fighters are central to force projection and deterrence strategies, the integration of a new powerplant on the Su-57 is closely watched by foreign defense establishments. The move is presented in Moscow not only as a technological milestone, but also as an indicator of industrial resilience and the future export positioning of the Russian fighter.
Rostec says the Su-57 has completed its first flight using the new Product 177 engine, kicking off a joint UAC and UEC flight test campaign that could shape the fighter’s future performance and export appeal (Picture Source: Rostec)
According to Rostec, specialists from UAC and UEC have “begun flight tests of the ‘Product 177’ engine as part of the fifth-generation Su-57 aviation complex,” with the aircraft piloted by Honored Russian test pilot Roman Kondratyev. The corporation reports that the sortie proceeded normally and that the engine functioned “in штатный режим” (within normal parameters), demonstrating reliable operation within the aircraft. Officially described as an engine for fifth-generation aviation systems, Product 177 delivers 16,000 kgf of thrust in afterburner, while also incorporating reduced fuel consumption across all operating modes and increased service life compared with previous-generation powerplants. Evgeny Marchukov, General Designer of the A. Lyulka Design Bureau within UEC, underlined that new materials and “innovative design solutions” have allowed UEC to achieve “significantly improved technical characteristics compared to earlier engines,” and stated that the first flight marks the beginning of joint work with UAC on Su-57 flight tests with the new engine.
Rostec
Rostec frames this engine milestone within a broader narrative of a combat-proven and continuously modernized Su-57 platform. The corporation recalls that the aircraft has “performed excellently in real combat conditions” and confirmed its compliance with fifth-generation requirements, including stealth characteristics. Built as a multirole frontline aviation complex, the Su-57 is intended to engage air, ground and maritime targets, operating around the clock, in adverse weather and under heavy electronic jamming, with low observability enabling it to strike in the presence of modern air defense systems. Rostec notes that experience gained in the “zone of the Special Military Operation” is feeding directly into modernization work, with expanded capabilities for both weapons and onboard systems. In this context, Sukhoi Design Bureau director Mikhail Strelets describes the Su-57 as “today the most sophisticated fifth-generation fighter,” while stressing that the platform is undergoing “evolutionary development” to increase combat capabilities and integrate new technologies more rapidly as operational needs evolve.
Rostec
From an operational standpoint, the move to Product 177 is intended to provide a tangible performance margin for the Su-57. Higher afterburning thrust, as officially stated, can be translated into improved climb and acceleration, better energy management in air-to-air combat, or the ability to carry heavier internal weapons loads with less impact on performance. Reduced fuel consumption across the flight envelope and extended engine life may support longer on-station endurance, more efficient long-range missions and lower through-life operating costs, factors that are increasingly important for both national and export operators. While Russian sources do not disclose detailed performance parameters, the combination of higher thrust, efficiency and resource suggests that the Su-57 could sustain more demanding mission profiles in heavily defended airspace, converting the extra margin into higher operating altitudes, more aggressive maneuvering or increased stand-off distance for precision weapons. In an environment characterized by dense surface-to-air missile coverage and complex electronic warfare, these incremental advantages can translate into a higher probability of mission success and survivability.
With an afterburning thrust of 16,000 kgf, or roughly 157 kN, Product 177 places the Su-57’s propulsion in a thrust class comparable to that of the F-22’s Pratt & Whitney F119, which is generally quoted at about 35,000 lbf, or 156 kN, in full afterburner. By comparison, the F-35’s F135 engine sits higher, around 43,000 lbf, or 191 kN, of afterburning thrust, giving it a clear edge in absolute power on a lighter single-engine airframe. Among European fourth- and 4.5-generation designs, individual engines such as the Eurofighter Typhoon’s EJ200 (about 90 kN with reheat) and the Rafale’s M88 (around 75 kN with afterburner) are significantly less powerful, which reflects the fact that they are used in pairs on twin-engine platforms. In other words, a single Product 177 should generate substantially more thrust than one EJ200 or M88, while two European engines together provide total installed thrust that is comparable to, or slightly above, what one Su-57 engine delivers.
Where the Russian powerplant will ultimately be judged is not only on peak afterburning thrust, but on how its dry thrust, fuel consumption and thermal and acoustic signatures measure up against benchmarks such as the F119 and F135. If UEC’s claims on reduced specific fuel consumption and increased service life are validated in service, a twin-engine Su-57 equipped with two 16,000-kgf engines would enjoy a very high installed thrust margin, placing it in the upper tier of global fighter propulsion even if it does not match the latest U.S. engines on every parameter.
At the strategic and industrial level, the first flight with Product 177 is presented as part of a long-term effort to anchor Russia’s fifth-generation air combat capability on a fully domestic technological base. Rostec indicates that the United Aircraft Corporation is currently implementing a program to expand production capacity, with the goal of increasing Su-57 deliveries to the Russian armed forces and “actively offering the Su-57 in export configuration to foreign customers.” The corporation adds that the aircraft is generating high interest abroad and claims that export deliveries are already underway, though no clients or quantities are named in the official text. A wide industrial cooperation of Rostec enterprises participates in the aircraft’s production, from airframe and avionics to engine development, reinforcing the message that Moscow intends to maintain sovereign control over critical technologies despite international sanctions.
For Russia’s partners or potential buyers with limited access to Western fifth-generation solutions, a Su-57 equipped with a modern engine such as Product 177 is positioned as an alternative pathway to advanced air combat capabilities. For NATO and its allies, this evolution will be monitored as an indicator of how quickly Russia can translate development work into serially produced aircraft that sustain or enhance its long-range strike and air-superiority posture.
The first flight of the Su-57 with the Product 177 engine thus does more than validate a new powerplant: it confirms that the Russian fifth-generation fighter program is entering a new stage where engine and airframe are being matured together as a single combat system. By pairing combat experience, ongoing upgrades to weapons and onboard electronics, and a higher-thrust, more efficient engine developed within Russia’s own industrial base, Moscow is signalling its intention to keep the Su-57 at the core of its airpower strategy while offering it more assertively on the export market. How quickly the Product 177 progresses through flight testing and into series production will now be a key indicator watched by defense planners, as it will shape both the operational reality of the Russian Aerospace Forces and the competitive landscape of the global fighter market over the coming decade.
Written by Teoman S. Nicanci – Defense Analyst, Army Recognition Group
Teoman S. Nicanci holds degrees in Political Science, Comparative and International Politics, and International Relations and Diplomacy from leading Belgian universities, with research focused on Russian strategic behavior, defense technology, and modern warfare. He is a defense analyst at Army Recognition, specializing in the global defense industry, military armament, and emerging defense technologies.