J-31在中国北部沈阳飞机公司的一处研究设施继续进行飞行测试。作为中国第二款第五代战斗机，J-31的出现使中国成为继美国之后，世界上第二个拥有两种第五代战斗机的国家。J-31机长约17米，翼展11.5米，尺寸与F-35“闪电II”相当，比F-22、J-20和PAK-FA都要小。一款代号为“F-60”的大比例J-31模型出现在2012年珠海航展上，表明中国有意将J-31作为F-35的国际竞争对手进行出口。一旦投入使用，J-31可能会与数量较少的J-20一同服役，组成类似美国空军F-35/F-22组合的“高低搭配”模式。J-31也可能部署在中国未来的航空母舰上，极大地提升其作战能力。巴基斯坦很可能是J-31的首个出口客户，因为伊斯兰堡希望以此来对抗印度购买的俄罗斯FGFA隐形战斗机。
据报道，J-31“鹘鹰”隐形战斗机采用了沈阳公司竞标中国重型第五代战斗机（由成都J-20获胜）失败的J-19的技术。自2012年秋季以来，J-31已在沈阳进行了至少六次试飞，第二架原型机正在组装中。与J-20照片受到的一些审查相比，J-31的研发保密程度较低。
为了减轻重量，J-31使用了大量的3D激光打印部件，包括钛合金翼梁。与F-35相比，J-31采用了两台俄罗斯RD-33小型发动机，而不是像AL-31或WS-10这样更大的发动机。这使得J-31的机身比F-35更扁平；这表明J-31更侧重于空优作战，因为扁平的机身意味着武器舱较小，但通过减少阻力提高了燃油效率和速度。J-31很可能可以在机翼下携带YJ-12反舰导弹等大型导弹，但与F-35一样，这将以牺牲隐身性为代价。俄罗斯米格飞机设计局总设计师弗拉基米尔·巴尔科夫斯基称赞J-31是“一项出色的国产设计”和“一台好机器”，是中国雄心勃勃的航空工业的成果。
[俄罗斯官员透露J-31发动机并描述中国销售情况](https://The/ J-31 continues flight testing at a Shenyang Aircraft Corporation research facility in northern China. As China’s second fifth generation fighter, the J-31 makes China the second nation in the world, after the United States, to have flown two fifth generation fighters. With a length of about 17 meters and an 11.5m wingspan, the J-31 is about the size of the F-35 Lightning II and smaller than the F-22, J-20 and PAK-FA. A large model of the J-31, designated as “F-60”, appeared at the Zhuhai 2012 Airshow, indicating a Chinese willingness to export the J-31 as a international competitor to the F-35. Once it enters service, the J-31 is likely to be serve alongside less numerous J-20s as part of a “high/low” combination, similar to the F-35/F-22 mix in the US Air Force. The J-31 is also likely to serve aboard future Chinese aircraft carriers, greatly enhancing their capabilities. Pakistan is likely to be the first export customer for the J-31, as Islamabad hopes to counter the Indian purchase of Russian FGFA stealth fighters. The J-31 “Gyrfalcon” stealth fighter reportedly uses technology from the J-19, Shenyang’s failed bid for the Chinese heavy 5th generation fighter (which the Chengdu J-20 won). The J-31 has conducted at least six test flights in Shenyang since fall 2012 and a second prototype is under assembly. Compared to censorship of some J-20 photos, there is less secrecy about the J-31’s development. To save weight, the J-31 uses an immense number of of 3D laser printed components, including titanium wing spars. Compared to the F-35, the J-31 uses two smaller Russian RD-33 engines instead of a larger engine like the AL-31 or WS-10. This gives the J-31 a flatter fuselage than the F-35; which suggests a more pronounced air superiority focus for the J-31, since a flatter fuselage results in a smaller weapons bay but improves fuel efficiency and speed by decreasing drag. It is likely that the J-31 could carry larger missiles like the YJ-12 anti-ship missile under its wings, but like with the F-35, at the cost of stealth. Vladimir Barkovsky, chief of the Russian MiG aircraft design bureau, has praised the J-31 as a “well done indigenous design” and “good machine” resulting from China’s ambitious aviation industry. https://www.ainonline.com/aviation-news/ain-defense-perspective/2012-11-23/russian-officials-reveal-j-31-engine-and-describe-sales-china/)
