Russia has reportedly delivered two newly built Su-57 Felon stealth fighters to its Aerospace Forces, marked with tail numbers “25” and “26.” These aircraft are believed to be the first Su-57s delivered in 2025, signaling a continued commitment to the fifth-generation fighter program despite ongoing production hurdles.
Images surfaced on social media on April 10, showing the two Su-57s being transferred to an undisclosed Russian airbase under tight security. Notably, neither the Russian Ministry of Defence nor the state defense conglomerate Rostec has officially acknowledged the deliveries, fueling speculation about the operational status and readiness of these aircraft.
The absence of formal announcements is consistent with the program’s history of secrecy and challenges. The Su-57 program has been plagued by delays, technical obstacles, and production inefficiencies, limiting the number of operational aircraft. As of late 2024, reports indicated that 22 Su-57s were in service, with plans to increase the fleet to 76 by 2028 .
The slow production rate of the Su-57 is attributed to several factors, including overlapping industrial demands, technological shortfalls, and persistent geopolitical constraints. Western sanctions, intensified after Russia’s 2022 invasion of Ukraine, have severely restricted access to foreign-manufactured avionics, AESA radars, high-performance sensors, and advanced electronic warfare systems . Consequently, Russia has had to rely on domestically developed substitutes, many of which are still in the prototype phase or do not meet fifth-generation operational benchmarks.
The Komsomolsk-on-Amur Aircraft Plant (KnAAPO), the primary assembly facility for the Su-57, is also tasked with producing Su-35 multirole fighters and the next-generation Su-75 “Checkmate” prototype. This has placed significant strain on technical personnel and production throughput.
A notable development in the Su-57 program is the integration of the AL-51F1 engine, also known as “Product 30.” This second-stage engine is designed to provide the Su-57 with supercruise capability—the ability to fly at supersonic speeds without afterburners—enhancing its stealth and combat effectiveness. The AL-51F1 delivers a thrust of 11,000 kgf in dry mode and up to 18,000 kgf with afterburners, allowing the Su-57 to cruise at Mach 2 while reducing its infrared signature .
The engine features advanced technologies, including flat nozzles and ceramic turbines, contributing to improved fuel efficiency and reduced radar cross-section. These enhancements are critical for the Su-57 to meet the full suite of fifth-generation fighter requirements.
Despite production challenges, Russia is actively seeking international buyers for the Su-57. At the Aero India 2025 exhibition, Rosoboronexport’s chief, Alexander Mikheev, announced that the Su-57 would be delivered to its first foreign buyer in 2025, though the purchasing country was not disclosed . Speculation suggests that Algeria may be the first export customer, with potential interest from India and North Korea .
However, concerns remain about Russia’s ability to scale up production to meet international demand, especially given the current limitations in manufacturing capacity and technological components.
The Su-57 program’s future hinges on overcoming production bottlenecks and fully integrating advanced technologies like the AL-51F1 engine. Successful deployment and operation of the Su-57 will not only enhance Russia’s air combat capabilities but also influence global fifth-generation fighter dynamics.
As the program progresses, attention will focus on the Su-57’s performance in operational settings, its integration with unmanned systems like the S-70 Okhotnik-B, and its competitiveness in the international arms market. The coming years will be critical in determining whether the Su-57 can fulfill its strategic promise and establish a significant presence in modern air warfare.
Despite production challenges, Russia is actively seeking international buyers for the Su-57. At the Aero India 2025 exhibition, Rosoboronexport’s chief, Alexander Mikheev, announced that the Su-57 would be delivered to its first foreign buyer in 2025, though the purchasing country was not disclosed . Speculation suggests that Algeria may be the first export customer, with potential interest from India and North Korea.
However, concerns remain about Russia’s ability to scale up production to meet international demand, especially given the current limitations in manufacturing capacity and technological components.
The Su-57 program’s future hinges on overcoming production bottlenecks and fully integrating advanced technologies like the AL-51F1 engine. Successful deployment and operation of the Su-57 will not only enhance Russia’s air combat capabilities but also influence global fifth-generation fighter dynamics.
As the program progresses, attention will focus on the Su-57’s performance in operational settings, its integration with unmanned systems like the S-70 Okhotnik-B, and its competitiveness in the international arms market. The coming years will be critical in determining whether the Su-57 can fulfill its strategic promise and establish a significant presence in modern air warfare.
