Summary
This document revises an earlier supplemental notice of proposed rulemaking (NPRM), applicable to certain Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-135BJ and Model EMB-145XR airplanes. The first supplemental NPRM would have required, for all airplanes, installation of an additional indication device to the clear-ice indication system. For certain airplanes, the first supplemental NPRM would also have required replacing the existing clear-ice indication lamp with a new, improved lamp. For certain other airplanes, the first supplemental NPRM would also have required modifying certain electrical connections to add an indication device to the clear-ice indication system; removing a certain placard; and re- activating the clear-ice additional indicator lamp. This new action revises the first supplemental NPRM by adding airplanes to the applicability. The actions specified by this new proposed supplemental NPRM are intended to prevent undetected build-up of clear ice on the wing surfaces, which could lead to reduced controllability of the airplane. This action is intended to address the identified unsafe condition.