Are you on Steam or Microsoft Store version?
Steam
Brief description of the issue:
I was flying the 747 and suddently the plane dived straight down without explanation, then i disabled it but if i turned it back and selected 42000ft altitude it would still not climb, all the temperatures of the engines were fine and live weather was off.
Detail steps to reproduce the issue encountered:
Fly the 747
Activate autopilot
Wait for disaster
Build Version # when you first started experiencing this issue:
Update GOTY (18th November)