Originally Posted by
OK465
Parked on the ground, you can hold the SS full forward for 8 seconds, 8 minutes, or 8 years and the THS will not move.....
.....because there is no change in the existing dynamic pressure.
Very true - 8 seconds (or thereabouts) was the value we got in the A320 sim with THS full NU, followed by sustained full-ND on the sidestick when we attempted the AF447 scenario. Approximately 8 seconds from full-NU to neutral, controlling roll with rudder rather than ailerons (due to stalled state).
NB. I'm well aware that this experience does not necessarily reflect the behaviour of the real thing in an aerodynamic sense, but the systems are the same - no reason to think THS return to neutral would have been much different...