# Proposed AD FAA-2005-23072: Pratt & Whitney JT9D-7R4 Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2005-26-09
- Products: Pratt & Whitney
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: March 1, 2007, 72 FR 9276
- Comments due: April 30, 2007
- Became: [AD 2005-26-09](https://openairdocs.org/ad/2005-26-09)
- Docket: FAA-2005-23072 (https://www.regulations.gov/docket/FAA-2005-23072, where comments are filed)
- Project: 2005-NE-38-AD
- FR document: E7-3561
- Official PDF: https://openairdocs.org/files/sha256/a2/37/a2373c77266dc18377ba015340fafa29e1b8b90dc8f4522dcd4257d2389fd340 (from https://www.govinfo.gov/content/pkg/FR-2007-03-01/pdf/E7-3561.pdf)
- Federal Register: https://www.federalregister.gov/documents/2007/03/01/E7-3561/airworthiness-directives-pratt-and-whitney-jt9d-7r4-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3D9D753A0A48E1FB862572910052D42F.0001
- Page: https://openairdocs.org/proposed/FAA-2005-23072

## Summary

The FAA proposes to supersede an existing airworthiness directive (AD) for Pratt & Whitney (PW) JT9D-7R4 turbofan engines. That AD currently requires inspection of the blade root thickness of 1st stage fan blades identified by part number (P/N) and serial number (SN) in the AD. This proposed AD would require the same actions but would correct 12 P/Ns, add 10 part SNs, and add the definition of next fan blade exposure to the compliance section. This proposed AD results from the discovery of inaccurate part quantity, part numbers, and serial numbers used in AD 2005-26-09. We are proposing this AD to prevent 1st stage fan blade fracture and uncontained engine failure, resulting in possible damage to the airplane.

## Notices in this docket

- Mar 1, 2007: Notice of proposed rulemaking (NPRM). (first notice), FR document E7-3561, comments due Apr 30, 2007 (https://www.federalregister.gov/documents/2007/03/01/E7-3561/airworthiness-directives-pratt-and-whitney-jt9d-7r4-turbofan-engines)

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