The electric trim actuator is mechanically linked to the artificial-feel bungee, and varies the neutral position of the bungee to provide longitudinal trim of the aircraft. The actuator is manually controlled through inputs from the trim switch on the control stick grip. High speed is used during manual trim, and low speed during automatic trim. The stabilizer shifting mechanism, shown in figure 9-7, consists of a shift sector and its linkage, plus cable that runs from the flap drive gearbox and the rudder cam shift mechanism. In normal operation, when flaps are extended, a cable running from a drum on top of the flap drive gearbox to the sector assembly of the shifting mechanism rotates the sector.
Linkage connecting the sector assembly and the control stick linkage is shifted.
Linkage shifting increases control stick travel. Stabilizer down travel is increased to a 24-degree maximum. A cable is also connected from the sector assembly to the rudder cam stop shifting mechanism, which increases rudder travel from 4 to 35 degrees each side of neutral. This action ports hydraulic pressure through the spin recovery selector valve and its flow regulators and check valve to the spin recovery cylinder, causing it to extend and shift the mechanism in the same manner as provided by the cable action. The two nonbypass-type filters in the system protect the intricate valving mechanisms of the actuator from contamination, and are vitally important to proper stabilizer operation.