Oh yeah... I remember all the hype about the mysterious super-fast Foxbat. The Warp-9 Superduper Ruski-Klingon suborbital battlestar that was gonna kill us all.
And then Viktor Belenko defected with one and we found out that it used vacuum tubes in its electronics, weighed a huge amount more than expected, and that every time it hit the high speed we thought was in its operational envelope, the engines had to be replaced when it landed.
I suspect this new bird is not going to be that bad. Let’s face it, it’s a lot easier for the Russians to buy tech these days than it used to be, but still, I do not expect to see the PAK-FA in operation in significant numbers before 2020.
I thought the Foxbat used vacuum tubes to improve avionics endurance, and boost its radar output.