Two J-20 fighter jets perform during an air show celebrating the 70th anniversary of the force's foundation, held in Changchun, Jilin province, on Thursday. [Photo by Zou Hong/chinadaily.com.cn]

The frequent public appearances of the Chinese Air Force's most advanced fight jet, the J-20, in October proves the Air Force's increasing confidence in the warplane, experts said on Tuesday.

The PLA Air Force released a video on Monday of the J-20, state broadcaster China Central Television (CCTV) reported on Monday.

Training in real-world exercises over the desert, sea and mountains, the report said the J-20 has showed off its increasing capabilities.

October has been a hectic month for the J-20 and a treat to the public, as the plane was reviewed at the National Day parade in Beijing on October 1 and performed at the Chinese Air Force's "open day" in Changchun, Northeast China's Jilin Province on October 17.

On October 13, the Air Force revealed on its Sina Weibo account that the J-20 had been assigned to an elite combat unit under the Eastern Theater Command named after Wang Hai, a flying ace in the Korean War (1950-53). On Saturday, CCTV invited Li Gang, the test pilot who flew the first J-20, to discuss his experiences with the aircraft.

"The J-20 used to be mysterious, and official sources seldom released any information," Fu Qianshao, a Chinese air defense expert, told the Global Times on Tuesday, noting that its frequent public appearances in October shows the Air Force is increasingly confident in its capabilities and is combat-ready, and Chinese pilots have mastered the use of the plane.

China was the fastest in the world to take a fifth generation fighter jet to the operational level, even faster than the US with its F-22 and F-35 stealth fighter jets, Fu said.

The J-20 made its first test flight in 2011, its public debut at Airshow China 2016 and entered military service in 2017.

More Chinese combat units will gradually get the J-20, and the plane is also expected to get upgrades in engine, avionics and weapons, Fu said.