Airworthiness Directives; Empresa Brasileira de Aeronautica, S.A. (EMBRAER), Model EMB-120 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to all EMBRAER Model EMB-120 series airplanes, that currently requires revising the Airplane Flight Manual (AFM) to include requirements for activation of the ice protection systems and to add information regarding operation in icing conditions; installing an ice detector system; and revising the AFM to include procedures for testing system integrity. That AD also requires installing the ice detector system in accordance with revised procedures. That amendment was prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. This amendment corrects and clarifies certain AFM procedures, and provides for an alternative AFM revision. The actions specified by this AD are intended to ensure that the flightcrew is able to recognize the formation of significant ice accretion and take appropriate action; such formation of ice could result in reduced controllability of the airplane in normal icing conditions.