Beijing has released footage of flight tests of an upgraded J-20A stealth fighter, with signs that the jets have been equipped with long-awaited high-thrust WS-15 engines and better avionics. According to a social media post by state news agency Xinhua on Wednesday, these aircraft are new prototypes of the J-20A, an upgraded version of the original J-20 stealth fighter. AdvertisementThe footage showed at least three J-20As in a yellow zinc-chromate primer taxiing on a runway. The J-20 is a twin-engined heavy stealth fighter that entered service in 2017. China has been developing its improved version, the J-20A, including upgrades to its aerodynamic layout, avionics and engines.