Summary
This document proposes adopting a new airworthiness directive (AD) for the specified Bell Helicopter Textron Canada (BHTC) model helicopters. The AD would require certain inspections of the main rotor yoke (yoke) for a crack, fretting, or buffer deterioration. If a crack is found, the AD would require replacing the yoke with an airworthy yoke before further flight. If fretting or buffer deterioration are found, the AD would require further inspecting the main rotor hub assembly (hub assembly) and repairing or replacing any unairworthy parts. Also, the AD would require a torque inspection of the flapping bearing retaining nuts at specified intervals. This proposal is prompted by the discovery of a crack in a yoke. The actions specified by the proposed AD are intended to prevent failure of the yoke and subsequent loss of control of the helicopter.