AD 2005-04-09 Amendment 39-13981

This amendment supersedes an existing airworthiness directive (AD) for the specified Bell Helicopter Textron Canada (BHTC) model helicopters that currently requires certain checks and inspections of the tail rotor blades. If a crack is found, the existing AD requires replacing the tail rotor blade (blade) with an airworthy blade before further flight. This amendment requires the same checks and inspections as the existing AD, but expands the applicability with the addition of two BHTC Model 430 helicopter serial numbers. This amendment is prompted by the manufacturer issuing revised service information that includes the additional two serial numbers. The actions specified by this AD are intended to detect a crack in the blade, and to prevent loss of a blade and subsequent loss of control of the helicopter.