Russia’s state aircraft and engine makers have begun flight testing a new powerplant for the Su-57 fifth-generation fighter jet, marking the first reported sortie of the aircraft equipped with the advanced Product 177 turbofan. The maiden flight took place on December 22, 2025, as part of a joint program between United Engine Corporation and United Aircraft Corporation.
Flight Test Phase Begins
According to Rostec, the Product 177 engine completed its initial flight on the Su-57 without issues, performing reliably and meeting the mission’s requirements. The aircraft used for the test, serial number 052, carried the new engine in place of the current AL-41F1 (Product 117) unit. Honored test pilot Roman Kondratyev flew the jet during the test sortie.
Product 177 is being positioned as a next-generation turbofan for the Su-57, offering higher thrust, better fuel efficiency and longer service life compared with earlier Russian fighter engines. Rostec says increased performance will support further development of the aircraft.
Technical Details
The new engine’s afterburner thrust is reported at about 16,000 kilogram force (roughly 157 kilonewtons), a figure slightly above the output of the Pratt & Whitney F119 that powers the U.S. F-22. Russian sources say the powerplant also shows reduced fuel consumption and improved durability.
Su-57 Fighter with Project 177 Engine Preceding First Flight Product 177 incorporates modern materials and design changes meant to raise performance across operating modes. It also retains advanced electronic controls and thrust vectoring capabilities seen in previous engine efforts.
Context of Upgrade
The Su-57 has flown to date with the AL-41F1, a derivative of older engine designs that served as an interim solution. The introduction of Product 177 represents a planned shift toward purpose-built propulsion for Russia’s top-tier fighter.
Rostec and UAC have displayed the engine and related technologies at recent air shows, highlighting the program as a cornerstone of ongoing upgrades to the Su-57 platform. The manufacturer has tied development work to broader efforts to boost production and expand export opportunities for the aircraft.
What’s Next
Flight testing will continue as engineers gather data on the new engine’s performance across conditions. If Product 177 progresses as planned, it could enter service on later Su-57 production batches and potentially support other Russian combat aircraft in future upgrades.
