Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for Bell Model 407 helicopters. This AD requires repetitive inspections of the tail rotor (TR) driveshaft segment assemblies and a torque check of the TR adapter retention nuts. This AD was prompted by a report of an in- flight failure of the TR drive system. The actions of this AD are intended to detect and correct an unsafe condition on these products.