well, According to CD, what J20 uses is not Fly-By-Wire (FBW) system ,but fly-by optical system. the following is the quoted from CD. here are the digestions: 1. J20 now uses fly-by-optical(FBO) system,instead of FBW system. 2. FBO is one generation ahead of FBW system. 3. the R&D of FBO was started by Yankees in 1975. but the tech didn't get mature until 2000. Yankees started to apply FBO tech to some birds such as B2,F22 and last model of F16 after 2000.