New Delhi: As more Rafale fighters join the Indian Air Force's fighter fleet, China has begun readying its best fighter, the J-20. 

The J-20 participated in a high-profile People's Liberation Army Air Force (PLAAF) exercise in Dingxin, in the Gobi desert, just south of Mongolia, in northern China, late last year. About six J-20s may have taken part in the exercise that involved live-firing. The H-6 bomber, deployed near Ladakh, was also involved in the ten-day exercise.

China has been trying to replace the Russian engine of the J-20 with a more advanced locally-made version. There are reports that the J-20 twin-seater, a trainer, has the WS-10 engine and could have the more powerful WS-15 in the future.

So far, the Chinese have built about 50 J-20s and they're, as expected split between their combat units and their training establishments, equivalent to the Indian Air Force's TACDE. All the new J-20s are powered by the WS-10 engine.

The Chinese say it is a Stealth fighter, which means it cannot be picked up by radars, but sources said that while the frontal part of the J-20 is stealthy, the same cannot be said about the rear of the plane. Which is why the Chinese are trying to develop serrated engine nozzles to reduce the 'signature' of the plane's tail. Nor is it very easy to maintain, requiring air-conditioned hangers for parking and servicing.

But the Chinese have plans for the J-20. There are plans to modify the plane for carrier operations. Currently, the PLAAF has two carriers-- the Liaoning, acquired from Russia, and the Shandong. The Shandong has been active, having sailed to the Yulin submarine base late last year.