How do you know WS-18 is low by pass? It looks like DKP30 engine, doesnt mean it performs like it. With new metallurgy, WS-18 spec is definitely better than old Russian engine. Plus, PLAAF seems very satisfy for WS-18 that they continue using this engine with very slow induction phase of WS-20.Are there any updates on when Y-20s will be produced with WS-20s? It doesn't make sense to me that J-20, J-10, Chinese flankers have all switched to the WS-10 in mass production but the Y-20 is still relying on the old low bypass WS-18s. Especially with the WS-15 and WS-10 progress, it doesn't make sense why this hasn't occurred yet.