I am working at Boeing as a lead math modeler. I believe Mr. Liu might reveal some "historical facts" in the old days (say 80's) But 30 years have passed and Institute 601 should be very different from 30 years ago. So we should have a fair attitude in order to make fair statements. We need the current facts then we may make fair judgment for China aviation industry (both commercial and defense). I often visit Chinese airlines and believe they have made great progress though still have lots of work to do.