Russia’s Su-57 stealth fighter jet has achieved a pivotal fifth-generation milestone with the successful first flight of its new Product 177 engine. ROSTEC, the Russian state corporation, confirmed on 22 December 2025 that the aircraft, piloted by honoured test pilot Roman Kondratyev, completed the sortie without issues.

The engine operated in normal mode, or normal parameters, marking the shift from ground tests to a dedicated flight-test campaign led by the United Aircraft Corporation (UAC) and United Engine Corporation (UEC).

This development underscores propulsion as the cornerstone of fifth-generation performance, influencing range, speed, and combat endurance. The Product 177, described as a fifth-generation powerplant, delivers 16,000 kgf (approximately 157 kN) of afterburning thrust. It promises reduced fuel consumption across all modes and extended service life compared to predecessors.

Evgeny Marchukov, General Designer at the A. Lyulka Design Bureau within UEC, highlighted innovative materials and design solutions. These enable significantly improved characteristics over earlier engines. The first flight initiates joint UAC-UEC efforts to integrate and validate the engine on the Su-57 platform.

ROSTEC positions this within the Su-57’s broader narrative as a combat-proven multirole fighter. The aircraft has excelled in real combat during the Special Military Operation, affirming its stealth and fifth-generation compliance. It engages air, ground, and maritime targets in all weather, under jamming, and amid modern air defences.

Sukhoi Design Bureau director Mikhail Strelets calls the Su-57 the most sophisticated fifth-generation fighter today. Ongoing evolutionary development incorporates combat lessons into weapons and avionics upgrades. This ensures rapid adaptation to emerging operational demands.

Operationally, Product 177 enhances climb rates, acceleration, and energy management for air-to-air engagements. It supports heavier internal payloads without compromising performance. Lower fuel use and longer engine life enable extended loiter times, efficient long-range strikes, and reduced lifecycle costs—critical for national and export fleets.

The engine’s 157 kN thrust rivals the F-22 Raptor’s Pratt & Whitney F119 at about 156 kN in afterburner. It surpasses the F-35’s F135 (191 kN) on a per-engine basis but reflects twin-engine design differences. Compared to single engines in European 4.5-generation fighters like the Eurofighter Typhoon’s EJ200 (90 kN) or Rafale’s M88 (75 kN), Product 177 offers superior individual power.

Twin Product 177s turbofans on the Su-57 would yield high installed thrust, placing it among global leaders. Success hinges on dry thrust, fuel efficiency, and signature management versus benchmarks like F119 or F135. Validation of UEC’s claims could enable demanding missions in contested airspace, boosting survivability.

Strategically, this milestone reinforces Russia’s domestic technological sovereignty amid sanctions. ROSTEC emphasises expanded Su-57 production via UAC, targeting higher deliveries to the Aerospace Forces. The fighter is actively marketed for export, with claims of underway deals, though details remain undisclosed.

A robust ROSTEC ecosystem—from airframes to engines—underpins production resilience. For partners excluded from Western fifth-generation options, the upgraded Su-57 offers advanced capabilities. NATO observers will track its progress as a gauge of Russia’s airpower sustainment and strike potential.

This flight test validates not just the engine but the Su-57 as an integrated system. Combat experience, avionics evolution, and efficient propulsion position it centrally in Moscow’s strategy. Export assertiveness signals competitive intent in the global market.

The pace of Product 177’s flight trials and serial production will shape outcomes. Delays could limit operational impact; swift integration would enhance Russia’s deterrence and appeal to buyers. Defence planners worldwide will monitor closely over the next decade.

Based On ROSTEC Report