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

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain EMBRAER Model EMB- 120 series airplanes, that currently requires revising the airplane flight manual (AFM), and either installing hydraulic tube assemblies incorporating a check valve, or visually inspecting the check valve if already installed and performing corrective actions if necessary. This action would add airplanes to the applicability of the existing AD. The actions specified by the proposed AD are intended to prevent the landing gear doors from becoming blocked from opening during application of emergency procedures in the event of a loss of hydraulics. This action is intended to address the identified unsafe condition.