What event was the plane that was powered by the WS-15 engine revealed at?
Xian WS-15: The WS-15 (), codename Emei, is a Chinese afterburning turbofan engine designed by the Shenyang Aeroengine Research Institute and manufactured by the Xi'an Aero-Engine Corporation, used to power China's Chengdu J-20 fighter, which would be able to achieve supercruise. Chengdu J-20:  The J-20 made its maiden flight on 11 January 2011, but the plane was officially revealed on China International Aviation & Aerospace Exhibition in 2016.
China International Aviation & Aerospace Exhibition