China's military is likely to pick the country's first active stealth fighter, the J-20, for its next generation aircraft carriers, according to military sources and a recent report on state media.

The J-20, made by the Chengdu Aerospace Corporation (CAC), appears to have a won a head-to-head contest with the FC-31, a fighter made by another company which is still undergoing testing.

A military insider told the South China Morning Post that the Central Military Commission, the People's Liberation Army's top decision-making body, now favored adapting the J-20 for its new carriers.

"The Chengdu Aerospace Corporation will announce some new products, which will include a new version of their J-20. You can guess what type it will be," the military insider, who requested anonymity because of the sensitivity of the subject, said.

The FC-31 was independently developed by CAC's sister company Shenyang Aircraft Corporation (SAC), which also produced the J-15 " the jets currently in use on the country's only active aircraft carrier, the Liaoning.

Both aerospace firms are subsidiaries of the state-owned giant Aviation Industry Corporation of China, which specializes in designing and developing military aircraft, and were set up to ensure benign competition between manufacturers.

However, the SAC has faced criticism from some military leaders and experts for being too conservative and failing to innovate because of its bureaucratic structure.

A recent program aired by the state broadcaster China Central Television also suggests the J-20 will be chosen.

An episode of Military Documentary shown on August 16 reported how the PLA Navy was selecting candidates for pilot training and illustrated the feature with a mock-up of jets that looked like J-20s taking off from a carrier.

Ground-based J-20s " also known as Powerful Dragons " entered service with the PLA Air Force in 2017. Mass production of the stealth fighters began late last year as China stepped up its efforts to counter the deployment of American F-22s and F-35s in the Asia-Pacific region.

If the selection of the J-20 is confirmed it will mark the end of a lengthy debate between its supporters and advocates of the FC-31 as to which would make a better carrier-based fighter.

Those who favored the J-20 said it was more advanced and reliable than the FC-31, but its supporters said it was more light and nimble.

"Both the J-20 and FC-31 have their advantages. The size of the J-20 is similar to the J-15 since both are powerful heavy fighters," Song Zhongping, a military commentator for Hong Kong-based Phoenix Television, said.

Song said the lighter FC-31 could be developed into a medium-sized carrier fighter that would complement the J-20 in future.

But another military source close to the PLA Navy said it would be almost impossible to develop both aircraft over the next few years given the risk of an economic downturn as the trade war with the US continues to escalate.

The source said China's next generation aircraft carriers would be with equipped electromagnetic catapults similar to those used on the US Navy's Ford-class supercarriers.

These enable the use of heavier fighters because they are more powerful than the older diesel systems used on older carriers.

"The key problem of the J-20 is not weight, but length. If it wants to be a carrier-based fighter jet, it needs to be made shorter."

Military insiders have previously said that CAC engineers are working to produce a shorter version of the J-20 that will work with the new launch system.

At present both the J-20 and F-31 still rely on Russian engines. The WS-15 engine that has been purpose built for the J-20 has undergone hundreds of hours of testing but has yet to meet reliability targets while the F-31 prototype does not have a purpose-built engine.

China's navy plans to build at least four carrier battle groups by 2030, three of which will be active at any given time.

Miliary analysts say China will need at least a decade to develop its new generation carrier-based fighters, so the J-15 will remain in service for at least a decade, if not two.

The J-15 made its maiden flight in 2009 and has been in service since 2012. They are the only fighters based on the Liaoning and will be used by its sister ship the Type 001A when it enters service, probably later this year.

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