AD FAA-2013-0556

We are superseding airworthiness directive (AD) 90-26-12 for Sikorsky Aircraft Corporation (Sikorsky) Model S-64E helicopters. AD 90-26-12 required checks of the main rotor blades for a crack. This new AD retains the actions required by AD 90-26-12, reflects that the type certificate (TC) for this model helicopter has been transferred to Erickson Air-Crane Incorporated (Erickson), and expands the applicability to include the similar Erickson Model S-64F helicopters. This AD is prompted by a need to expand the applicability to include Model S-64F helicopters and clarify the applicable main rotor blades by part number. These actions are intended to detect a crack in the main rotor blade and prevent blade separation and subsequent loss of control of the helicopter.