"The fighter can stall from high speed, stopping in less than a second. Then it demonstrates an ability to descend tail first without causing a compressor stall. It can also recover from a flat spin in less than a minute."
Link to video of the jet at air-attack.com: air-attack.com
So, will the Russians sell it to the Chinese? Why don't we [the U.S.] have one? Or do we...?