Some of us found a bug of those planes with TVC system.I got two planes in my post list, the Su-57 Frazor & the Su-35 (latest version), both of them got the issue that when you enter the end of a flight, you still got about 20% fuel in the body, then the plane will be uncontrollable, seems like the dead weight has been burned too. I have spent tons of time to work on those planes, and I found that is a bug of COM in the end.Trust me it is a quite important issue to be fixed, and I believe some of you guys met the bug before.