Following the recent release of images on social media, the first test flight involving a Chinese Air Force J-20A stealth fighter equipped with the new WS-15 engine has been recorded. These engines are intended to replace the WS-10 models previously fitted to this variant of the aircraft. The images in question appear more than two years after official sources stated that the engine had already entered production, which—if sustained over time—would represent a significant leap in capability for the platform and a major milestone for the Chinese aerospace industry.
It is worth recalling that the development of the WS-15 engine dates back to the 1990s, when it was pursued in parallel with the design of the J-20 fighters themselves, which today form the backbone of China’s stealth airpower. This effort has repeatedly been described as the “Achilles’ heel” of the country’s aerospace industry, as various technical obstacles and resulting delays initially led to the integration of Russian Saturn AL-31 engines on the platform, followed later by the adoption of the WS-10 during serial production. However, the WS-10 was originally designed for the J-10 fighters of the Chinese Air Force and fell short of the performance requirements desired for a stealth fighter of this class.
This point is particularly relevant given that, although many technical aspects of the WS-15 remain undisclosed, the primary objective behind its development has been to match the performance of the F119 engines used on the U.S. F-22, widely regarded as one of the most capable air superiority fighters in the world. In this context, the WS-10 proved insufficient in terms of speed, acceleration, and supercruise capability, as well as in its ability to generate enough electrical power to support future systems planned for integration on the J-20.
By way of illustration, preliminary data on WS-15 prototypes indicated the ability to generate up to 36,000 pounds of thrust, with projected targets reaching 40,000 pounds. When compared to the WS-10—rated at around 32,000 pounds of thrust—the improvement is evident. The aforementioned F119 engines, according to U.S. manufacturer Pratt & Whitney, deliver approximately 35,000 pounds of thrust.
Beyond the purely technical aspects, the progress reflected in this recorded test flight also represents a further step toward consolidating indigenous industrial capabilities and achieving greater strategic autonomy in the future. As noted by various analysts, the development of high-performance jet engines had until now been one of the advantages that the West still maintained over Beijing in the medium term, underscoring the rapid pace of advancement achieved by the Chinese industry.
Finally, it is equally relevant to note that the integration of the new WS-15 engines is not the only upgrade undertaken to enhance the J-20’s combat capabilities. Among other known changes are a redesigned radome, increased internal fuselage volume—potentially indicating greater fuel capacity or space for new avionics systems—and a cockpit positioned higher, all of which have been observed in previous imagery.
Cover image credits to the respective rights holder.
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