Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model ERJ 170 Airplanes

The FAA is adopting a new airworthiness directive (AD) for all EMBRAER Model ERJ 170 airplanes. This AD requires revising the Airworthiness Limitations section (ALS) of the airplane maintenance manual (AMM) to include new, specific maintenance tasks related to the incorporation of a new horizontal stabilizer actuator. This AD also requires revising the ALS of the AMM to include revised repetitive inspection intervals for certain tasks in the maintenance plan related to the aileron and flap/slat flight controls system. This AD results from safety assessments of the aileron and flap/slat flight controls system, conducted after the type certification of the airplane, which showed that some dormant faults did not comply with the safety assessment criteria. We are issuing this AD to prevent failure of the aileron and flap/slat controls system, which could result in reduced controllability of the airplane.