# Proposed AD FAA-2006-23742: Pratt & Whitney (PW) JT9D-7R4 Series Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2007-17-21
- Products: Pratt & Whitney
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: November 9, 2007, 72 FR 63510
- Comments due: January 8, 2008
- Became: [AD 2007-17-21](https://openairdocs.org/ad/2007-17-21)
- Docket: FAA-2006-23742 (https://www.regulations.gov/docket/FAA-2006-23742, where comments are filed)
- Project: 2005-NE-53-AD
- FR document: E7-22005
- Official PDF: https://openairdocs.org/files/sha256/e0/71/e071ceb92b082b90698a9e05bfb140263a5a898059a50e77349a6f60f146eab7 (from https://www.govinfo.gov/content/pkg/FR-2007-11-09/pdf/E7-22005.pdf)
- Federal Register: https://www.federalregister.gov/documents/2007/11/09/E7-22005/airworthiness-directives-pratt-and-whitney-pw-jt9d-7r4-series-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F7734063638AC6918625738E0055A89B.0001
- Page: https://openairdocs.org/proposed/FAA-2006-23742

## Summary

The FAA proposes to supersede an existing airworthiness directive (AD) for PW JT9D-7R4 series turbofan engines. That AD currently requires removing certain reduced cooling flow 2nd stage high pressure turbine (HPT) vane assemblies installed in certain 2nd stage HPT vane cluster assemblies. It also requires a visual and a fluorescent penetrant inspection (FPI) of the 2nd stage HPT air seal assembly, P/N 815097. This proposed AD would require a visual and fluorescent penetrant inspection (FPI) of all part number (P/N) 2nd stage HPT air seal assemblies that were used with reduced cooling flow 2nd stage HPT vane assemblies. This proposed AD results from the manufacturer identifying additional P/N air seal assemblies that are affected by the unsafe condition. We are proposing this AD to prevent uncontained failure of the 2nd stage HPT air seal assembly, leading to engine in-flight shutdown and damage to the airplane.

## Notices in this docket

- Apr 26, 2006: Notice of proposed rulemaking (NPRM). (first notice), FR document 06-3922, comments due Jun 26, 2006 (https://www.federalregister.gov/documents/2006/04/26/06-3922/airworthiness-directives-pratt-and-whitney-jt9d-7r4g2-turbofan-engines)
- Feb 2, 2007: Supplemental notice of proposed rulemaking (NPRM); reopening of comment period., FR document E7-1707, comments due Apr 3, 2007 (https://www.federalregister.gov/documents/2007/02/02/E7-1707/airworthiness-directives-pratt-and-whitney-pw-jt9d-7r4-series-turbofan-engines)
- Nov 9, 2007: Notice of proposed rulemaking (NPRM)., FR document E7-22005, comments due Jan 8, 2008 (https://www.federalregister.gov/documents/2007/11/09/E7-22005/airworthiness-directives-pratt-and-whitney-pw-jt9d-7r4-series-turbofan-engines)

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