Russia's United Engine Corporation (UEC), part of the state-owned Rostec, has presented India with a proposal for a new engine: the Izdeliye 177S (also referred to as Product 177S).
This advanced engine is being offered as a potential solution for two key Indian Air Force (IAF) programs: the ongoing Super-30MKI upgrade and the future Advanced Medium Combat Aircraft (AMCA) Mk2. The engine was showcased at the Aero India 2025 exhibition.
The Izdeliye 177S represents a substantial upgrade from the existing AL-41F1 engine, which currently powers both Russia's Su-57 fighter jet and India's large fleet of over 260 Su-30MKI aircraft.
The 177S reportedly generates a maximum thrust of 142 kN (approximately 14,500 kgf), a significant increase over the 123 kN thrust of the AL-31FP engines currently used in the Indian Su-30MKIs.
The new engine also boasts an improved thrust-to-weight ratio of 9.5:1. It incorporates technology derived from the AL-51 engine, intended for the second-stage (Izdeliye 30) version of the Su-57.
Key improvements include thrust vector control (TVC) nozzles with stealth treatments to minimize radar and infrared signatures, greater fuel efficiency, and a longer operational lifespan, projected to surpass the 4,000-hour service life of the AL-31FP.
UEC has stated that the 177S is designed as a "drop-in" replacement, compatible with the existing Su-30MKI assembly lines at Hindustan Aeronautics Limited (HAL), and has offered local manufacturing options under India's "Make in India" initiative.
For the Super-30 upgrade program, which initially targets the modernization of 84 Su-30MKIs, the 177S engine, combined with the indigenously developed Virupaksha AESA radar, could significantly enhance the aircraft's capabilities. This upgrade would effectively transform the Su-30MKIs into 4.5-generation fighters with some 5th-generation characteristics.
In the longer term, the 177S could serve as an interim engine for the AMCA Mk2. While the AMCA Mk1 is slated to use the General Electric F414 engine (producing 98 kN of thrust), India's long-term objective is to develop an indigenous engine in the 110-130 kN thrust class, likely in collaboration with either Safran or Rolls-Royce, with a target availability date in the mid-2030s. The 177S could bridge the gap until this indigenous engine is ready.
However, there's a caveat to Russia's proposal. Reports, including discussions on social media platform X, suggest that Russia may not proceed with flight testing of the 177S until a firm commitment is received from potential customers like India. This approach, reminiscent of some Cold War-era Soviet practices, prioritizes securing funding before completing development.
This contrasts with the development path of the Su-57, which underwent flight testing with the AL-41F1 before the introduction of the AL-51 (Izdeliye 30), which first flew in 2022.
Currently, the 177S exists only as a ground-tested prototype. Rostec's reluctance to invest further without a confirmed order could be due to budgetary pressures, potentially exacerbated by Western sanctions imposed since 2022, or a strategy to secure India's commitment.
This development strategy differs significantly from those used in the United States and China. For instance, the F-35's F135 engine underwent flight testing in 2000, years before entering full-scale production. Similarly, China's WS-15 engine has been tested on J-20 prototypes by 2023.
For India, the situation presents a strategic choice: commit to an engine that has not yet been flight-tested, with the promise of co-production and technology transfer, or wait for flight data that might not materialize without an initial investment.
The Russian offer comes at a critical juncture for India. The Super-30 upgrade program, which has faced delays, including those related to engine supply (HAL's delivery of only two Tejas Mk1As in 2024 was partially attributed to shortages of GE engines), requires a dependable and powerful engine to ensure the Su-30MKI fleet remains operational and effective beyond 2035.
The enhanced thrust and stealth capabilities of the 177S could provide a significant advantage over the F-16s and JF-17s operated by Pakistan's Air Force, particularly when combined with upgraded avionics and the integration of BrahMos missiles.
Online speculation also suggests that the 177S could potentially rival the thrust of China's J-20, although the capabilities of the J-20's WS-15 engine remain uncertain.
