Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Model A320 series airplanes, that currently requires repetitive measurements of the deflection of the elevator trailing edge; inspections of the elevator servo controls and their attachments; and replacement of worn or damaged parts, if necessary. This action would require periodic inspection of the elevators for excessive freeplay; repair or replacement of worn parts, if excessive freeplay is detected; replacement of the elevator servo controls with modified elevator servo controls; and modification of the elevator neutral setting. It would also revise the applicability to include additional models of airplanes. This proposal is prompted by additional reports of severe vibration in the aft cabin of Model A320 series airplanes and studies which indicate that the primary cause is excessive freeplay in the elevator attachments. The actions specified by the proposed AD are intended to prevent excessive vibration of the elevators, which could result in reduced structural integrity, leading to reduced controllability of the airplane.