Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for Robinson Helicopter Company (Robinson) Model R44, R44 II, and R66 helicopters. This AD requires inspecting the main rotor blade (MRB). This AD was prompted by a determination that some MRBs may have reduced blade thickness due to blending out corrosion. The actions are intended to prevent the unsafe condition on these products.