Summary
This document proposes adopting a new airworthiness directive (AD) for specified restricted category helicopters. The proposed AD would require updating the product identification, extending the application of the AD to other models, continuing the existing retirement time for certain main rotor tension-torsion (TT) straps, and adding the TT strap part numbers to the applicability. This proposal is prompted by the need to expand the applicability to additional restricted category helicopters and to add two part numbers to the applicability. The actions specified by the proposed AD are intended to prevent failure of a TT strap, loss of a main rotor blade, and subsequent loss of control of the helicopter.