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 installation of an additional drain at the fuselage aft section. This action is necessary to prevent mechanical blockage of the elevator control cables due to the freezing of water collected inside the fuselage between the rear pressure bulkhead and the fire wall of the auxiliary power unit. Such cable blockage could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.