Originally Posted by allflight57
... how do the PCU stops only let the flight controls droop about an inch or so, when the actual amount of deflection is much more during normal operation with the hydraulics pressurized? Anyone have a close up pic of the PCU or a detailed diagram so I can see a little better how it works.
Wiht hydraulic power available, the complete PCU moves to actuate the elevator.
Without hydraulic power you actuate the (weight balanced) elevator mechanically, but you have a kind of "lost motion" until the primary input crank hit the mechanical stops.
So on ground, when you switch of the hydraulic, the elevator drop a little bit.