The J-20 is China's Raptor; not the FC-31. Not to splash some cold water here but the FC-31 is mostly a failed project currently unless they can persuade the PLAN to be its next carrier fighter (which is unlikely). Shenyang, as usual, is inferior to Chengdu and used to rely exclusively on producing copies. In fact, their J-16 AESA radar had to be completely redesigned after quality issues ... something that the 14th institute has never experienced. The fact is Shenyang has never produced any "genuine" fighter; the FC-31 is a weird mixture of stolen F-35 blueprints with a twin engine configuration whose engines are still smoky. Thank god SAC did not win the fifth generation tender in 2007 otherwise there would be nothing remotely close to the J-20. It's gotten much better in recent years with its J-16, J-15, and J-11 variants but the truth is they're all based on Russian flanker designs. Compare that with Chengdu, whose jets are constantly undergoing innovation and being upgraded. The PLAAF, to many's disbelief, had to buy 24 Su-35 jets just to cover for the J-11D's many failures in 2015 (although the program still hasn't been cancelled yet ... oddly). I have always been surprised (and frustrated) by Shenyang's lack of innovation ... maybe it's because of CPC patronage? So for the people who compare the FC-31 to the F-22; it's not even close. If the rumors are true that the 611 institute has submitted a bid for China's 5th generation carrier-fighter, the FC-31 is dead ... completely.