The bungee consists of two springs, which have different spring constants. The stick force caused by the bungee is proportional to stick displacement. At near neutral, the bungee provides a high stick force that decreases a short distance from neutral and gradually increases with the amount of stick displacement. 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.