Quasispecies

This is a good point but in my case I'm in surface mode all the way down from 35km.

Yes, I'm using SAS retrograde hold. And I think you're right, I just landed safely on Tylo with SAS turned off, I was slowly dropping vertically and gently touched down with hardly any instability. So going forward I'll get everything under control using SAS and then toggle it off. Hopefully that should do it. Thanks.

I'm testing a new heavy lander on Tylo. My ship is based around a mark 2 lander can on a large central fuel tank and a Mammoth engine and 6 side fuel tanks with terrier engines. I'm also carrying two detachable side stages with ore tanks and ISRUs to refuel after landing. I'm using RCS and Vernor engines to hold me in retrograde and keep me stable. I get down to 10m/s or less and a slow vertical descent, with everything looking great. At around 100m from the ground - with no inputs from me - the ship suddenly becomes unstable and starts swinging wildly, making landing very difficult, usually resulting in a crash. I've messed around with gimbal limits on the Mammoth, but can't seem to resolve this satisfactorily. Any ideas?