# Airworthiness Directives; Pratt & Whitney JT9D-7R4 Turbofan Engines
> **Rule** · Final rule; request for comments. · Published 2005-12-27 · Effective 2006-01-11 · 70 FR 76381
## Document
- **Document number:** 05-24448
- **Category:** airworthiness
- **Manufacturer:** Pratt & Whitney JT9D-7R4 Turbofan
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 70 FR 76381
- **Publication date:** 2005-12-27
- **Effective date:** 2006-01-11
- **FAA docket:** Docket No. FAA-2005-23072
## Abstract

The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney (PW) JT9D-7R4 turbofan engines. This AD requires inspection of the blade root thickness of 1st stage fan blades identified by part number (P/N) and serial number (SN) in this AD, by a repair station approved by PW to perform the inspection. This AD results from a report that a repair station created their own repair and performed it on 520 1st stage fan blades, without approval from PW. We are issuing this AD to prevent 1st stage fan blade fracture and uncontained engine failure, resulting in possible damage to the airplane.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2005/12/27/05-24448/airworthiness-directives-pratt-and-whitney-jt9d-7r4-turbofan-engines)
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