Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters

We are adopting a new airworthiness directive (AD) for Erickson Air-Crane Incorporated (Erickson) Model S-64F helicopters. This AD requires inspecting for cracking or working rivets in each left and right splice fitting (transition fitting), the pylon bulkhead assembly-canted (bulkhead assembly), and the pylon steel strap (strap). This AD was prompted by several reports of cracking in the transition fittings, the bulkhead assembly, and the pylon. The actions specified by this AD are intended to detect cracking in the rotary rudder boom or pylon due to fatigue, and to prevent failure from static overload and subsequent loss of control of the helicopter.