Serial Production of Super cruising Su-57 with Stage 2 Engine Started in Early 2023Ten Su-57 fighters delivered to the RuAF in 2023 were powered by Stage 2 Izdeliye 30 engines, according to a TASS source.All Su-57 aircraft delivered in 2024 will feature the Stage 2. The Stage 2 engine features serrated exhaust nozzle, also referred to as chevron nozzle, which improves thrust efficiency, stability, maneuverability and performance, while reducing engine noise. Most importantly, serrated exhaust nozzles can contribute to reduction in infrared (IR) and radar signatures of the aircraft. By altering the exhaust plume's temperature distribution and shape, serrated nozzles can make the fighter harder for IR and radar sensors to detect and track the aircraft.According to the Wikipedia, the Stage 2 engine offers 11 tonnes (107.9 kN) dry and 17 tonnes (167 kN) in afterburner.The Stage 1 L-41F1 produces 9 tonnes (88.3 kN) of dry thrust and 14.5 tonnes (142.2 kN) of thrust in afterburner. A Su-57 powered by the Stage 2 engine can supercruise at Mach 1.5 to Mach 1.6. All production Su-57 fighters transferred to the Russian Aerospace Forces (VKS) in 2024 will receive second-stage engines. This was reported to TASS by two high-ranking sources close to the Russian Aerospace Forces.“The engine of the second stage has been tested and is ready for operation,” said one of the agency’s interlocutors. The second source confirmed this information and added that “all production fifth-generation Su-57 aircraft transferred to the Aerospace Forces in 2024 will receive a fifth-generation engine.”TASS does not have official confirmation of this information.According to the agency’s interlocutor, in 2023, more than 10 Su-57s with first-stage engines have already been transferred to the Aerospace Forces. They successfully solve problems in the special military operation zone. “There are no plans to replace the first-stage engines on the Su-57s already transferred to the Aerospace Forces with new engines,” he said, explaining that even with the first-stage engine, the Su-57 surpasses the American F-35 in its characteristics.Earlier, specialists from the A. M. Lyulka Design Bureau explained that the first stage engine provides the Su-57 with such characteristics as super-maneuverability, thrust-to-weight ratio, and low visibility. Another advantage is the oxygen-free plasma ignition system of the main and afterburner combustion chambers.