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

We are superseding an existing airworthiness directive (AD) for all EMBRAER Model ERJ 170 airplanes. That AD currently requires revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA) to incorporate new structural inspection requirements. Since we issued that AD, during full scale fatigue testing, cracks were found in certain structural components of the airplane. Analysis of these cracks resulted in the manufacturer modifying the ALS of EMBRAER 170 Maintenance Review Board Report (MRBR), to include new inspections tasks, or modifying the current tasks and their respective thresholds and intervals. This new AD requires revising the maintenance program to incorporate new or revised structural inspection requirements. We are issuing this AD to detect and correct fatigue cracking which could result in the loss of structural integrity of the airplane.