The United Engine Corporation (UEC) of Russia’s Rostec State Corporation will showcase its AL-31FN Series 5 engine at the Zhuhai Airshow 2024 in China, marking the first time this improved engine model will be exhibited outside Russia. Set to run from November 12 to 17, the Zhuhai Airshow offers an international platform for groundbreaking advancements in aerospace technology, with the AL-31FN Series 5 poised to highlight the potential of modernized Russian engines to elevate Chinese fighter capabilities.
The AL-31FN Series 5, a re-engineered variant, was specifically developed by the Salyut division to boost the performance of China’s Chengdu J-10. Promising significant improvements in altitude capabilities, range, and power, the Series 5 is expected to give the J-10 enhanced agility and endurance, bolstering its operational value for the People’s Liberation Army Air Force (PLAAF).
The AL-31FN engine was initially tailored to meet the specifications required for the Chengdu J-10, an aircraft introduced in the early 2000s as a multipurpose, lightweight fighter. Salyut, part of UEC, adapted the AL-31F—primarily designed for the Su-27—by moving the gearbox from the top to the bottom, optimizing the engine for the J-10’s specific configuration.
The initial AL-31FN variant produced approximately 12.7 tonnes-force of thrust, with the Series 3 later increasing this to 13.7 tonnes-force. Now, the Series 5 version showcased at Zhuhai is expected to align closely with the capabilities of the AL-41F1, the engine powering Russia’s advanced Su-57 stealth fighter, which boasts a thrust of 15 tonnes-force. This enhancement could mean significant improvements in the J-10’s operational range, flight ceiling, and agility, offering Chinese forces a potential advantage in high-altitude engagements and long-range missions.
While the full specifications of the AL-31FN Series 5 remain confidential, the model likely shares similarities with Russia’s AL-41F1, suggesting thrust levels close to 15 tonnes-force. Given this thrust increase, the Series 5 can elevate the performance of J-10 fighters to meet modern aerial warfare demands.
- Extended Range and Altitude: Enhanced thrust translates into increased flight range and operational altitude, potentially allowing J-10 fighters to execute long-duration missions without refueling, thereby expanding their strike radius.
- Improved Maneuverability: Higher thrust gives the J-10 agility gains, critical for dogfighting and evading surface-to-air threats.
Potential for Advanced Armament Integration: With greater power, the Series 5 can support heavier weaponry, such as hypersonic missiles, and advanced multispectral pods, which could serve both offensive and defensive roles on the battlefield.
In parallel, India is making strides to modernize its fleet of Su-30MKI fighters under a $7.5 billion upgrade program sanctioned by the Ministry of Defence (MoD) earlier this year. Led by Hindustan Aeronautics Limited (HAL)
with contributions from the Defence Research and Development Organisation (DRDO), this project is set to introduce significant avionics, radar, and electronic warfare advancements to 84 Su-30MKI aircraft.
- Phase 1 will focus on integrating next-generation avionics and Active Electronically Scanned Array (AESA) radar systems.
- Phase 2 aims to enhance flight control mechanisms and potentially introduce new weapon systems.
The centerpiece of the radar upgrade is the Virupaksha AESA radar, an advanced radar platform potentially derived from the Uttam AESA radar used on India’s LCA Tejas Mk-1A. Unlike the Uttam, which includes around 700 transmit-receive (TR) modules, Virupaksha’s larger profile will permit it to incorporate more modules, expanding detection range and target acquisition precision. This will enhance the Su-30MKI’s situational awareness, a crucial edge in modern air combat scenarios.
India’s modernization approach also includes integrating an indigenous infrared search and track (IRST) system. This addition, along with electronic warfare capabilities, aims to provide the Su-30MKI with better tracking and targeting accuracy for both air-to-air and air-to-ground combat.
Despite the scope of these upgrades, the Su-30MKI airframe and engine—particularly the AL-31FP—will remain unchanged, which presents some potential limitations. The AL-31FP, while reliable, produces 12.5 tonnes-force of thrust, lower than the AL-41F1 engine used in Russia’s latest fighters. Thus, the upgraded Su-30MKIs may face power constraints, particularly when equipped with advanced, power-intensive sensors and weaponry.
The decision to retain the AL-31FP has drawn scrutiny, with critics arguing that the more powerful and fuel-efficient AL-41F-1S should have been considered.
- Increased Power and Efficiency: With 16% more thrust and better fuel efficiency, the AL-41F-1S would allow the Su-30MKI to carry heavier weapon systems and advanced surveillance pods, essential for fulfilling future mission requirements.
- Longer Engine Life: Reports from Russian sources suggest that the AL-41F-1S has an extended lifespan, reducing lifecycle costs and offering an operational edge.
- Compatibility with Heavy Ordinance: More powerful engines facilitate the use of heavy, long-range missiles like hypersonic cruise missiles, which are increasingly essential for strategic air dominance.
Such upgrades would have positioned the Su-30MKI to meet emerging threats and align with evolving air combat demands. By contrast, retaining the AL-31FP may restrict the modernized Su-30MKI’s capabilities, potentially affecting the Indian Air Force’s operational flexibility and its ability to carry sophisticated, energy-intensive systems.
China’s methodical improvements to the J-10’s engine reflect a proactive approach to military modernization, with the PLAAF continuously pushing the boundaries of the platform’s potential. This strategy demonstrates a forward-looking vision, contrasting with the Indian Air Force’s more conservative path, which has led some analysts to question why India remains dependent on legacy engines for its frontline fighters despite significant defense budget allocations.
China’s upgrades signify an agile, adaptive approach, wherein each iteration of the J-10 is optimized to leverage new technologies and power capabilities. This has resulted in a fighter jet that, while originally classified as a light multirole aircraft, has become an increasingly formidable platform.
In contrast, the Indian Air Force’s reliance on the AL-31FP for the Su-30MKI fleet, coupled with HAL’s long-term licensing arrangement with Russia, has sparked debate within defense circles. Critics argue that India’s approach reveals missed opportunities for technological advancement and self-reliance, particularly given HAL’s access to AL-31FP technology under the Transfer of Technology (ToT) agreement signed in 2000.
The 2000 agreement between India and Russia, allowing HAL to license-produce AL-31FP engines, was seen as a critical step toward indigenous engine manufacturing. However, analysts argue that HAL could have used this opportunity to advance local engine expertise, perhaps positioning itself to develop improved versions of the AL-31FP or even explore new indigenous designs.
Instead, HAL has largely confined its operations to assembling Russian kits under licensed production, a practice that some say reflects a “sense of entitlement” rather than a proactive effort to innovate. As a result, India remains reliant on Russia for engine technology, despite two decades of production experience.
The recent September 2024 contract between India’s Ministry of Defence and HAL for 240 AL-31FP engines worth over ₹26,000 crore ($2.2 billion) further entrenches this dependence. As per the contract, HAL’s Koraput facility will manufacture 30 engines per year, sustaining India’s Su-30MKI fleet over the next decade.
While this deal secures the operational viability of India’s current Su-30MKI fleet, it reflects India’s preference for continuity over innovation. The additional engines, while critical for maintaining fleet readiness, underscore India’s continued reliance on a dated propulsion system rather than embracing more advanced alternatives like the AL-41F-1S.
