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

Resumo

We propose to supersede an existing airworthiness directive (AD) that applies to all EMBRAER Model ERJ 170 airplanes. The existing 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 manufacturer modifications of the ALS of Embraer ERJ 170 Maintenance Review Board Report (MRBR), which include new inspections tasks, or modification of the current tasks and their respective thresholds and intervals. This proposed AD would revise the maintenance program to incorporate new or revised structural inspection requirements. We are proposing this AD to detect and correct fatigue cracking which could result in the loss of structural integrity of the airplane.