Russian Aircraft Corp. Announces Next Generation Engines For Su-57 Fighters to Begin Deliveries Soon

CEO of the Russian State run United Aircraft Corporation Vadim Badekha has announced that a new type of engine being developed for the Su-57 fifth generation fighter under the Product 177 program will begin deliveries and integration “in the coming years.” “Today, the Su-57 fully meets the requirements for a fifth-generation fighter. The next-stage engine is Product 177. We should talk about equipping the Su-57 fighter with it not as a step necessary for the Su-57, but rather as additional capabilities that we will receive. We believe this will happen in the coming years,” he stated. His statement strongly asserted that the AL-41F-1 engines currently integrated already meet the requirements for fifth generation capabilities. Badekha elaborated that the engines are currently undergoing trails, and that their first flight has already taken place.

The Su-57 was reported to have made its first flight with the Project 177 engine in December 2025, with the state defence conglomerate Rostec announcing that specialists “begun flight tests of the ‘Product 177’ engine as part of the fifth-generation Su-57 aviation complex.” Rostec’s statement added that the engine performed within normal parameters while demonstrating its reliability. The nature of Product 177 program remains highly uncertain, with one possibility being that it is the name for a specific variant of the AL-51F engine that was previously announced to be being developed for the Su-57. Another possibility is that work on the AL-51F has been cancelled, and that the new engine is intended as a replacement, possibly due to difficulties meeting the ambitious specifications of the AL-51F.

Although the Soviet Union led the world in fighter engine development throughout the Cold War, with the AL-31F introduced in 1984 for the Su-27 fighter having had a highly competitive performance, progress stalled considerably after the state’s disintegration. The Su-57 as a result has been powered by an enhanced derivative of the AL-31F, which uses technologies from cancelled Soviet fifth generation fighter programs to increase its thrust/weight ratio and reduce its maintenance needs. The AL-41F-1 is nevertheless significantly less sophisticated or efficient than the current industry leaders, the WS-15 that powers China’s J-20 fighter, and the F135 powering the U.S. F-35 fighter. Reliance on a less advanced engine limits the Su-57’s flight performance, reduces its range, increases maintenance needs, and limits the power available for onboard subsystems such as radars and directed energy weapons. 

Rostec in December highlighted that the Product 177 engine had a reduced fuel consumption across all operating modes, and that its service life was greater than those of previous-generation powerplants, while portraying its development as a milestone in ongoing efforts to comprehensively modernise the Su-57. Sukhoi Design Bureau director Mikhail Strelets described this as part of the Su-57’s “evolutionary development.” Elaborating on the new capabilities provided by the powerplant, General Designer of the A. Lyulka Design Bureau responsible for its development, Evgeny Marchukov, observed that new materials and “innovative design solutions” have allowed for the achievement of “significantly improved technical characteristics compared to earlier engines.”

The announcement of continuing work on Project 177 closely coincides with the announcement by Vadim Badekha that the United Aircraft Corporation has begun work on the first flight prototype commissioned for the S-75 fifth generation fighter program, otherwise known as the Light Tactical Aircraft program. While the fighter was previously expected to be powered by the AL-51F, albeit in single configuration as opposed to the Su-57’s twin configuration, the announcement of the new engine’s development raises the possibility that it will power both the Su-57 and its lightweight counterpart the S-75. It remains possible that the AL-51F will also enter service as an alternative powerplant for both fighter types, and that export clients will be offered a choice of both engines, much as the U.S. currently offers both the F110 and less powerful F100 engines for the F-16 Block 70/72 fighter. With the S-75 being marketed as a very low cost fifth generation fighter, offering an option for a lower cost engine could help strengthen its position on export markets.