# Proposed AD FAA-2006-24487: Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, PW4090-3, and PW4098 Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2006-22-13
- Products: Pratt & Whitney
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 9, 2006, 71 FR 33412
- Comments due: August 8, 2006
- Became: [AD 2006-22-13](https://openairdocs.org/ad/2006-22-13)
- Docket: FAA-2006-24487 (https://www.regulations.gov/docket/FAA-2006-24487, where comments are filed)
- Project: 2006-NE-13-AD
- FR document: 06-5242
- Official PDF: https://openairdocs.org/files/sha256/ac/b3/acb36c72b3c33048c2cfe33e33ec37b68749ac8ea25d7e379cc66bef78f5aaaf (from https://www.govinfo.gov/content/pkg/FR-2006-06-09/pdf/06-5242.pdf)
- Federal Register: https://www.federalregister.gov/documents/2006/06/09/06-5242/airworthiness-directives-pratt-and-whitney-pw4074-pw4074d-pw4077-pw4077d-pw4084d-pw4090-pw4090-3-and
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7C249D458DB736EE862571880046EB70.0001
- Page: https://openairdocs.org/proposed/FAA-2006-24487

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, PW4090-3, and PW4098 turbofan engines, with certain front turbine hub part numbers installed. This proposed AD would require a onetime visual inspection of the anti-rotation slots in the front turbine hub, for a machining nonconformance, and its replacement if the inspection failed. This proposed AD results from a report of a crack found in an anti- rotation slot of a front turbine hub, during overhaul shop inspection. The anti-rotation slot geometry was not machined in conformance with the design drawing. We are proposing this AD to prevent uncontained engine failure, damage to the airplane, and injury to passengers.

## Notices in this docket

- Jun 9, 2006: Notice of proposed rulemaking (NPRM). (first notice), FR document 06-5242, comments due Aug 8, 2006 (https://www.federalregister.gov/documents/2006/06/09/06-5242/airworthiness-directives-pratt-and-whitney-pw4074-pw4074d-pw4077-pw4077d-pw4084d-pw4090-pw4090-3-and)

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