Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-300, - 400, and -500 series airplanes. This proposal would require replacing certain aileron/rudder trim control modules with a new module that contains an improved rudder trim switch to reduce internal friction. This proposal is prompted by reports of sticking conditions in the rudder trim switch. The actions specified by the proposed AD are intended to prevent such sticking, which could result in uncommanded movement of the rudder and consequent deviation of the airplane from its set course.