The file photo shows a J-20 stealth fighter jet attached to the Chinese PLA Air Force flies through the clouds overhead during a flight training exercise. (eng.chinamil.com.cn/Photo by Yang Jun)

Chinese military analysts said constant upgrades are expected for China's J-20 fighter jet, after foreign media reported recently that a new and more powerful variant of the stealth aircraft has appeared.

The new J-20 features changes to the shape of the aircraft, which might improve its aerodynamic and performance capabilities as well as low-observable qualities, US media outlet thedrive.com reported on Friday, citing unverified photos circulating on social media.

One of the most notable changes is the modified, flattened cockpit canopy that blends into the raised spine, the report said.

This kind of aerodynamic arrangement likely has the effect of improving performance and handling during transonic flight by reducing the drag on the airframe, and the enlarged spine could also provide useful space for additional avionics and fuel, thedrive.com said.

It is also expected that the J-20 will eventually replace the current standard domestically developed WS-10 engines with the more powerful WS-15 engines, according to the report.

The report is based on unconfirmed information and remains only speculative, a Chinese military expert who requested anonymity told the Global Times on Sunday.

But it is natural that the J-20 will keep on receiving upgrades to enhance its capabilities, just as it has done over the past few years, the expert said.

Comparing its first public appearance at the Airshow China 2016 with its latest appearance at the Airshow China 2022, the J-20 has already undergone many changes.

"All J-20s participating in the Airshow China 2022 were equipped with domestically developed engines, and the avionics were completely upgraded to the latest version," said Major Li Weipeng, a J-20 pilot, at a press conference at the Airshow China 2022 in Zhuhai, South China's Guangdong Province in November. 

The J-20 will increase not only in terms of the number being produced, but also in terms of its capabilities, analysts said.