Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain EMBRAER Model EMB-120 series airplanes. This proposal would require removal of the upper channel fairings and their shims; and rework of the riveting holes, the aileron sealing canvas (aerodynamic seals), and the protective covers of the trim tab hinge fittings of the aileron and elevator. This proposal is prompted by reports of binding of the aileron due to water freezing between the upper channel fairings and the surface of the leading edge of the aileron. The actions specified by the proposed AD are intended to prevent water from freezing between the upper channel fairings and the surface of the leading edge on the aileron, which could result in binding of the aileron and subsequent reduced controllability of the airplane.