Airworthiness Directives; Bell Helicopter Textron, Inc. Model 204B, 205A, 205A-1, 205B, 212, and 412 Helicopters

摘要

This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron, Inc. (BHTI) Model 205B, 212, and 412 helicopters, that currently requires a repetitive magnetic particle inspection of the main transmission lower planetary spider. This amendment expands the applicability to include the BHTI Model 204B, 205A, and 205A-1 helicopters. This amendment is prompted by the need to apply the magnetic particle inspections required by that AD to additional BHTI model helicopters, as well as more clearly state the applicable compliance times for these inspections. The actions specified by this AD are intended to prevent a fatigue failure of the main transmission lower planetary spider, which could result in failure of the main transmission, and subsequent loss of control of the helicopter.