China’s Air Force released on its weibo social media account two pictures, which show four J-20 stealth fighter jets flying in formation. As of 2017, it is reported that control system, stealth coatings and hull materials, and infrared sensors still have technical issues as does the reliability of its WS-15 engines. Some prototypes use the … Continue reading China ramping J20 stealth fighter production and should have improved WS-15 engine by 2019