Airworthiness Directives; Bell Helicopter Textron, Inc. Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 Helicopters

摘要

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron, Inc. Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters. This proposal would require removal and replacement of certain crosstube assemblies (crosstubes). This proposal is prompted by two accidents attributed to crosstube failures, as well as 27 field reports that indicate that corrosion or metal fatigue may cause a failure of the affected crosstubes. The actions specified by the proposed AD are intended to prevent failure of the crosstubes and subsequent loss of control of the helicopter.