Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-135 and -145 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to all EMBRAER Model EMB-145 series airplanes, that currently requires repetitive replacement of the bleed-air check valve and associated gaskets on the bleed low-pressure lines of the engines with new parts. This amendment continues to require repetitive replacement of the bleed-air check valves and associated gaskets. Additionally, this amendment provides for optional terminating action for the repetitive replacement of bleed-air check valves by installing new improved check valves, and adds airplanes to the applicability of the existing AD. This amendment also clarifies that the replacement and follow-on actions are required for the left- and right-hand engines. The actions specified by this AD are intended to prevent failure of the bleed-air check valves on the bleed low-pressure lines of the engines, which could result in engine compressor stall and consequent flameout of the affected engines. This action is intended to address the identified unsafe condition.