# Proposed AD FAA-2011-0731: Pratt & Whitney Corp. (PW) JT9D-7R4H1 Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2011-25-10
- Products: Pratt & Whitney Division
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: July 13, 2011, 76 FR 41144
- Comments due: August 29, 2011
- Became: [AD 2011-25-10](https://openairdocs.org/ad/2011-25-10)
- Docket: FAA-2011-0731 (https://www.regulations.gov/docket/FAA-2011-0731, where comments are filed)
- Project: 2010-NE-39-AD
- FR document: 2011-17622
- Official PDF: https://openairdocs.org/files/sha256/d6/4a/d64ac4d4feba6746d093988d24661b1ad51d2beada8a2a119b0289e0c5427354 (from https://www.govinfo.gov/content/pkg/FR-2011-07-13/pdf/2011-17622.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/07/13/2011-17622/airworthiness-directives-pratt-and-whitney-corp-pw-jt9d-7r4h1-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5B04D4A4B91C1ED8862578CC004BF47A.0001
- Page: https://openairdocs.org/proposed/FAA-2011-0731

## Summary

We propose to adopt a new airworthiness directive (AD) for all PW JT9D-7R4H1 turbofan engines. This proposed AD would require removing certain high-pressure compressor (HPC) shafts before their certified life limits, and establishes a new, lower life-limit for these parts. This proposed AD was prompted by reports of cracks in five HPC shafts. We are proposing this AD to correct the unsafe condition on these products.

## Notices in this docket

- Jul 13, 2011: Notice of proposed rulemaking (NPRM). (first notice), FR document 2011-17622, comments due Aug 29, 2011 (https://www.federalregister.gov/documents/2011/07/13/2011-17622/airworthiness-directives-pratt-and-whitney-corp-pw-jt9d-7r4h1-turbofan-engines)

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