Hazelnuts39
Per your service ceiling for 447 (actual), one concludes this flight was bumping at trouble, saved only by extra mach (.82). With "extra" speed to "burn", will this autopilot "hunt"? A gentle rolly coaster at 37,000 could get critical if the PF allows automatic hunting to maintain a/s/altitude, no? If the upsy downsy causes a trip out, isn't the PF in a crapshoot to ascertain where and when to input controls? A PIO could follow an APIO, yes? Isn't it up to chance (possibly) whether it's STALL or overspeed at the beginning (continuation) of upset?
much respect,
bear