The Chengdu J-20 is a single-seat, twinjet, all-weather, stealth, fifth-generation fighter aircraft developed by China’s Chengdu Aerospace Corporation for the People’s Liberation Army Air Force (PLAAF).
According to military analysts, China’s ambitions to arm J-20 fighter jets with high-tech weapons, such as lasers or particle beams, may be frustrated by its underpowered engines.
The initial prototypes of J-20 used Russian Saturn 117S engines—the same engine that the Su-57 stealth fighter jet uses. But the Chinese engineers then switched to the WS-15, a domestic version of the Russian engine. However, they failed to achieve the desired results as their engine wasn’t producing enough thrust for the aircraft to fly at its intended speeds. So, the Chinese engineers shifted to modifying the existing WS-10C, an engine designed for fourth-generation aircraft. But this engine has still to produce results.
As a result of the avionic shortcomings caused by the underperforming engines, the Chengdu J-20 might be limited in what future weapons it will be able to carry.
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According to Ridzwan Rahmat, a principal defence analyst at military publisher Janes said directed-energy weapon systems required large amounts of energy to be effective, and the limited thrust from the J-20’s WS-10 engines, initially designed for earlier generations of fighters, might be a major constraint.
“There are lingering questions over whether China has managed to achieve the thrust required on the J-20 on current payloads with the locally produced WS-10 engines,” Rahmat said.
“As such, loading the aircraft with more payloads, such as power systems for DEW, will have an effect on the aircraft’s range and maneuverability.
“Additionally, it is unclear how DEW systems will perform in high-speed environments. When an aircraft comes close to the speed of sound, it produces shock waves and aero-optics flow disturbances that degrade the quality of the lasers in use in DEW systems.”
Song Zhongping, a former PLA instructor, said directed-energy weapons might become a default for future Chinese fighter jets since they could be used discreetly and for an infinite time, but added:
“The J-20 needs more thrust and stable power generation to fully utilise directed-energy weapons.”
As J-20 aircraft seeks to compete in a fifth-generation battlespace these shortcomings with engine need to resolve as the American F-22 Raptor and F-35 Lighting II are superb aircraft and they currently give a tough competition to the Chinese counterparts.