SOURCE: AFI
The recent unveiling of China’s sixth-generation stealth fighter jet with a trijet engine configuration has sparked discussions among defense analysts regarding the country’s progress in high-thrust jet engine technology. Defense analyst Ranesh Rajan, speaking to AFI, suggested that this design choice reflects China’s ongoing challenges in developing engines capable of producing the thrust required for a strike-optimized stealth fighter-bomber.
Rajan noted that the trijet configuration is an unusual choice for a modern stealth platform, where twin-engine designs are typically preferred for their efficiency and streamlined stealth profiles. This choice, according to him, indicates that the WS-10C engines currently in use are unable to deliver the required thrust for a twin-engine configuration.
For comparison The Pratt & Whitney F135, which powers the Lockheed Martin F-35 Lightning II, generates a maximum thrust of 181 kN. The B-21 Raider, a stealth bomber unveiled by the United States, employs two F135-like engines, with an estimated combined thrust sufficient for its maximum takeoff weight (MTOW) of 81,647 kg.
Based on the trijet design, Rajan estimates that the Chinese stealth fighter-bomber has an MTOW of approximately 50,000 kg. This is significantly lower than the MTOW of the B-21 Raider, suggesting that the aircraft is optimized for shorter strike missions with a relatively modest payload.
The use of three engines instead of two indicates that China has yet to achieve a breakthrough in producing engines with a thrust range of 150-180 kN—a capability critical for powering larger and more versatile stealth aircraft.
While the trijet design compensates for the lack of a high-thrust engine, it likely comes at the cost of reduced stealth, higher maintenance requirements, and increased fuel consumption. A trijet configuration introduces additional exhaust signatures, which could compromise the aircraft’s overall stealth characteristics compared to twin-engine designs. The reliance on three engines suggests that the WS-10C, despite upgrades, cannot match the performance of Western engines like the F135. This limitation might restrict the aircraft’s operational range and payload capacity.
China’s advancements in stealth technology and aerodynamics are evident in its latest fighter-bomber, but the trijet design underscores an area where it still lags: jet engine development. Developing a high-thrust engine capable of powering future stealth platforms in twin-engine configurations remains a critical challenge for China’s aviation industry.
For India, the Chinese sixth-generation jet’s trijet configuration is a reminder of the importance of indigenous engine development programs. With the AMCA program under development, ensuring access to a high-thrust engine that meets future requirements is paramount.