icedown

SAS tends to over control, try using the far assistance. The autos can help, and DCA will limit control movements, since SAS is all or nothing.

When your TWR is > 10.

Found an issue with Cd on a the S2 Fuselage Adapter. I'm not sure if it's with B9 or FAR though. When flying, the Cd that shows up when tinted is very high, nearly as high as the cockpit. It is not as much so when the part is revered, but still noticeable. There is one behind the precoolers and one on in front of the Sabre M on the SSTO in the screenshots.

Using the statistics tool that comes with FAR, I've found that there is a CoL shift as you pass into the higher mach speeds, and it tends to shift forward. The easiest way to figure if this is what's getting you is have the far window open and note the absolute pressure and mach that you lose control, drop back into the SPH and plug them into the statistics tool and see what turns red, which will probably be Mw. also wouldn't hurt to put a 2HOT on it to verify the temperature for the statistics window as well.

One other thing besides control surfaces is the amount of thrust. High TWR and acceleration can be bad as well, especially with an engine that gimbles. With a lot of acceleration, it can cause a rocket to be very unstable as well. I usually limit my rockets to 18-20m/s.

Is this a problem when moving things like KAS winches when they are "docked" do another vessel? Or capable of it?

I'm looking into the VAB part limit movement problem. It's my first time looking into mods for this game, but I've been able to find my way around it pretty well. The only think I can't figure out it where it actually moves the models for the parts, or more specifically, what functions actually move them.