SOURCE: AFI
India’s reliance on foreign engine technology for its frontline fighter jets has long been a strategic vulnerability. Among these, the Russian AL-31F engine, which powers the Indian Air Force’s (IAF) Su-30MKI fleet, represents a pivotal piece of technology that India has been unable to indigenize or reverse-engineer. Despite decades of operation and maintenance experience, India has not successfully developed an indigenous alternative, a situation that could have serious repercussions on India’s defense programs, especially as it advances toward its ambitious Advanced Medium Combat Aircraft (AMCA) project.
This article explores why failing to indigenize the AL-31F could set back India’s defense capabilities, how detuned versions of the AL-31F could have supported the AMCA, and a comparison with China’s achievements in reverse engineering engines for its J-20 stealth fighter program.
The AL-31F, a product of Russia’s Ufa Engine Industrial Association (UMPO), is a highly capable afterburning turbofan engine that provides 123 kN of thrust, enabling the Su-30MKI’s agility and power. India’s Hindustan Aeronautics Limited (HAL) has mastered only the licensed assembly and overhaul of the AL-31F but lacks rights to the engine’s core intellectual property. Unlike China, which has aggressively reverse-engineered foreign engines, India has refrained from this approach due to technical and legal constraints.
While the AL-31F has served India well on the Su-30MKI, the lack of an indigenous equivalent has made the IAF susceptible to geopolitical dependencies and supply chain disruptions. Moreover, as India strives for a fifth-generation fighter platform, the Advanced Medium Combat Aircraft (AMCA), the absence of a domestically developed or adapted AL-31F derivative limits India’s ability to create an indigenous powerplant, risking delays in AMCA’s deployment and escalating costs associated with foreign dependencies.
As India looks to field its AMCA stealth fighter, an indigenous engine is a crucial factor in realizing the program’s independence and cost-effectiveness. India’s GTRE Kaveri engine, originally planned for the Light Combat Aircraft (LCA) Tejas, has faced years of development challenges, rendering it unsuitable for AMCA’s higher power requirements. A detuned or enhanced AL-31F could have provided an interim solution, offering a reliable, proven power source to accelerate the AMCA program without immediate reliance on new, complex engine designs.
If India had embarked on reverse-engineering the AL-31F in parallel with Russian cooperation, it might have developed a ‘detuned’ or optimized AL-31F variant suitable for the AMCA’s twin-engine configuration. A detuned AL-31F could have delivered slightly reduced thrust at a much lighter weight, supporting the AMCA’s design needs while ensuring compatibility with India’s industrial capabilities. This approach would have not only saved considerable time and resources but also enabled India to phase in advanced indigenous engines in the future once their development was fully realized.
In contrast, China’s approach to engine development has been aggressive and strategic. The Chinese J-20, a fifth-generation stealth fighter developed by Chengdu Aerospace Corporation, was initially powered by Russian AL-31FN engines. However, to break dependency on Russian supplies and achieve self-reliance, China invested heavily in reverse engineering and developing its own engines.
China’s WS-10 and WS-15 engine programs are notable examples of its ambitious efforts to replace foreign engines. Although the WS-10 initially suffered from reliability issues, China succeeded in refining it, deploying it on its J-10, J-11, and J-16 aircraft. Today, China’s WS-15 engine, designed specifically for the J-20, is nearing operational status. Despite a long, challenging development path, China’s WS-15 aims to match the power and efficiency of the American F119 engine used in the F-22 Raptor, and with sustained support and investment, it is likely that China will soon fully power its J-20 with indigenous engines.
China’s focus on reverse engineering has enabled it to advance its aerospace capabilities by not only replicating but also innovating upon existing designs. In contrast, India’s conservative stance has delayed such efforts, leaving it reliant on foreign suppliers to meet its advanced combat jet needs.
The Risks of Failing to Indigenize Engine Technology
The lack of an indigenous engine for AMCA and other advanced platforms poses several long-term strategic risks for India:
Reduced Export Potential: An indigenous AMCA equipped with a foreign engine will have limited export appeal due to licensing restrictions and dependence on foreign suppliers. Indigenous engines would enhance the platform’s self-sufficiency and exportability.
Operational Vulnerability: India’s reliance on Russian engines, especially amid geopolitical shifts, exposes its fleet to potential supply chain disruptions. Without a backup, Indian platforms could be grounded if Russian supplies were interrupted.
Increased Costs and Delays: Every delay in indigenous engine development adds to program costs. Procuring engines from abroad for AMCA could cost millions in foreign exchange and delay project timelines.
Technological Dependence: Dependence on foreign engines restricts India’s ability to customize and upgrade its engines according to its operational needs. Engine development is also a bedrock of aerospace knowledge, which India risks forfeiting by not focusing on reverse engineering.