# Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters (Type Certificate Previously Held by Sikorsky Aircraft Corporation)
> **Rule** · Final rule. · Published 2013-11-22 · Effective 2013-12-27 · 78 FR 69987
## Document
- **Document number:** 2013-27635
- **Category:** airworthiness
- **Manufacturer:** Erickson Air-Crane Incorporated
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 78 FR 69987
- **Publication date:** 2013-11-22
- **Effective date:** 2013-12-27
- **FAA docket:** Docket No. FAA-2013-0556
## Abstract

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.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2013/11/22/2013-27635/airworthiness-directives-erickson-air-crane-incorporated-helicopters-type-certificate-previously)
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