To me, the damn bird wanted to dive all the time. And yes, I broke the tail section right before that repairing session. Tried fixing things with trim...just got worse so I turned off all trim. Tried turning off the autopilot (that vertical thing I guess, the default "light" autopilot) and that sort of helped but there I was without autopilot. Aaaaand then the bird wanted to nose down again, like too much. Got tedious, I rage quit! ;)
All this on regular Caucasus map.