Summary
This document proposes adopting a new airworthiness directive (AD) for Erickson Model S-64F helicopters. The AD would require inspections for cracking or working rivets in each left and right splice fitting (transition fitting), the pylon bulkhead assembly-- canted (bulkhead assembly), the pylon steel strap (strap), and the attaching rotary rudder boom and pylon structure. This proposal is prompted by several reports of cracking in the transition fittings, the bulkhead assembly, and pylon. The actions specified by the proposed 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.