let me do you a favour popsci.com and give you a BIG hint in something you forgot ..
The Shenyang J-31 (F60), rumored to be nicknamed "Gyrfalcon" (鹘鹰), or Falcon Eagle, is a twin-engine, mid-size fifth-generation jet fighter currently under development by Shenyang Aircraft Corporation. The fighter has been referred to as F-60, J-31 and J-21 (Snowy Owl) in media reports... the wikipedia page continues.
but there's a couple BIG facts that you should know.
1. the chinese domestic engines a behind their ambitions, as such they realy on the russians to supply them with engines, and the russians have already been ripped off with the like of the J-15 so they're hesitent to give them the larger engines needed for the j-20 in large numbers.. in other words: this will be flying before the j-20 is in any large numbers
2. the plane looks just like a twin engine f-35, you know.. that plane the chinese stole all those secrets on.
3. it's already made it's first flights
the fact that you forgot this well known new piece of inventory is telling... next time, expand the number to 15 and do a better job than the stuff off the top of your head you happen to remember... yeeash