Originally Posted by
Clandestino
I am not saying that what I vaguely recall is correct or even if so, has something to do with the subject. I flew 320 last time 14 years ago but ISTR that during my TR I was told that loss of hyd power to one elevator means loss of not half but three quarters of pitch authority as surviving elevator would be limited to half the normal travel to reduce torque loads on rear fuselage.
Half elevator will have to move double to produce dynamic load of both elevators. So they will keep hitting the extremities that can damage the elevator. So it's movement is restricted to less than full. That makes it less than half effective. This is known.