Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain EMBRAER Model EMB-120, EMB-120ER, and EMB-120RT series airplanes. This proposal would require removal of a certain fastener, if applicable, and sealing of the corresponding fastener hole. This action is necessary to prevent contact between one of the bolts that attaches the direct current (DC) relay box on the left-hand side of the airplane and one of the power terminals of electrical emergency contactor 2, which could result in a short circuit in the DC relay box, and consequent partial loss of the electrical system, and degraded operation of airplane systems. This action is intended to address the identified unsafe condition.