Which component is used to adjust the pitch trim in case the main stabilizer trim fails?

The component used to adjust the pitch trim in case the main stabilizer trim fails is the alternate stabilizer trim. This system serves as a backup to the primary trim mechanism, allowing pilots to maintain control of the aircraft's pitch attitude in the event of a failure. The alternate stab trim system ensures that the aircraft can still be trimmed for level flight, providing essential functionality and safety.

While the elevator trim wheel and rudder trim are indeed part of an aircraft's control surfaces, they serve different purposes. The elevator trim wheel is used for fine adjustments to the elevator's position and primarily affects the aircraft's longitudinal stability rather than acting as a backup for the stabilizer trim. Rudder trim is specifically used for adjusting yaw, not pitch. The yaw damper, on the other hand, enhances stability and control during flight but does not directly relate to pitch trim adjustments. Thus, the alternate stabilizer trim is specifically designated to address situations where the primary trim system becomes inoperative.