If the servo actuator itself jammed (as I understand is suspected), not just a jammed pilot valve (as would be indicated by the SERVO JAM warning light mentioned in an earlier post), control of that A/C could not be maintained by any pilot, I would think. Something you don't train for, there is nothing you could do about it. Imagine, any movement of the controls would move only two out of the three actuators, leaving the swash plate fixed at the ceased actuator, giving control responses that would be completely unpredictable to a flying pilot. Add the AFCS giving inputs, some of which would be fed back to the controls, and all through the mixing unit, things get ugly really fast. Catastrophic single point failures, yikes.