Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Airbus Model A319, A320, A321, A330, and A340 series airplanes, that currently requires revising the Airplane Flight Manual (AFM) to require the flightcrew to discontinue use of any Instrument Landing System (ILS) receiver for which a certain caution message is displayed. It also requires, for certain airplanes, replacing any faulty ILS receiver with a new, serviceable, or modified unit, and provides for optional terminating action for the AFM revisions. That amendment was prompted by a pilot's report of errors in the glide slope deviation provided by an ILS receiver. This action would require accomplishment of the previous optional terminating action. The actions specified by this proposal are intended to detect and correct faulty ILS receivers and to ensure that the flightcrew is advised of the potential hazard of performing ILS approaches using a localizer deviation from a faulty ILS receiver, and advised of the procedures necessary to address that hazard. An erroneous localizer deviation could result in a landing outside the lateral boundary of the runway.