Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for various restricted category helicopters. This AD requires cleaning and visually inspecting certain main rotor (M/R) blades and, depending on the outcome of the inspections, repairing or replacing the M/R blades. This AD was prompted by a report of an M/R blade with multiple fatigue cracks around the blade retention bolt hole. The actions are intended to detect a crack in the M/R blade, and prevent failure of the M/R blade and subsequent loss of helicopter control.