Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters

We are adopting a new airworthiness directive (AD) for the Erickson Air-Crane (Erickson Air-Crane) Model S-64F helicopters. The amendment requires, at specified intervals, certain inspections of the rotating swashplate assembly (swashplate) for a crack. If a crack is found, this AD also requires, before further flight, replacing the swashplate with an airworthy swashplate. This AD is prompted by a report from the manufacturer of a swashplate cracking during fatigue testing. We are issuing this AD to prevent loss of a swashplate due to a fatigue crack, loss of control of the main rotor system, and subsequent loss of control of the helicopter.