The more we think about it, the more it smells like bs. Having said that, J-31 is in desperate need of better worksmanship to match J-20 and do justice to the shaping Lockheed Martin engineers so kindly surrendered
So Ace, when and where were YOU personally hands-on with the FC-31 proof of concept aircraft?? and for your information those Sino-Flankers are a hell of a lot slicker than the Russian birds, and yes, I have been very up close and very personal with a couple of Mig-29s, if you look down the flanks of SUKHOI's SU-35 demo bird 08, she's just rather wavy..
So the FC-31 is a proof of concept aircraft, as such it is a pieced together, one off airplane built to show form, function, and basic capability, it is not a reflection of SAC's build quality, and they are very capable of turning out very slick aircraft, look at the J-15's, very pretty, straight, well built aircraft, likely a much higher "pride of workmanship" displayed than those mass produced Russian Sukhoi's and Mig's,,, which are very effective, as evidenced by China buying the SU-35,, (OVT the number ONE reason, avionics likely the second, capability NOW the third)??
So apologies if you think I'm picking on you, just sticking up for a fine airplane....