Mechanical feedback is provided by the differentiating lever, as in the manual mode. When operating in the series mode, control surface displacement is not reflected at the control stick. In this mode, stabilizer movement is controlled by input signals from the AFCS alone. Both series and parallel mode solenoid valves are energized. Flight system pressure is ported to the electrohydraulic servo valve and the mechanical input lockout piston.
Fluid pressure stabilizes the lockout piston and holds the mechanical input lever.
There is no mechanical feedback, since the mechanical input is locked. Additional electrical signal feedback is provided by a transducer, which is mechanically linked to the stabilizer actuating arm. In the parallel mode, the control stick follows the motion of the stabilizer. All joints between the pushrods and bell cranks or idlers contain self-aligning bearings to compensate for any misalignment during operation and airframe deflections in flight that might cause binding. Artificial feel is provided by the artificial-feel bungee.