Action
Final rule; request for comments.
Summary
We are adopting a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model AB412 helicopters. This AD requires visually inspecting the main rotor swashplate outer ring (outer ring) for a crack and replacing that outer ring if a crack exists. This AD is prompted by two cases of cracks caused by fatigue on certain outer rings. These actions are intended to prevent the failure of the outer ring, which would lead to loss of main rotor blade pitch control and subsequently loss of helicopter control.