# Proposed AD FAA-2015-0869: Pratt & Whitney Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2015-21-04
- Products: Pratt & Whitney
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 8, 2015, 80 FR 32316
- Comments due: August 7, 2015
- Became: [AD 2015-21-04](https://openairdocs.org/ad/2015-21-04)
- Docket: FAA-2015-0869 (https://www.regulations.gov/docket/FAA-2015-0869, where comments are filed)
- Project: 2015-NE-11-AD
- FR document: 2015-13742
- Official PDF: https://openairdocs.org/files/sha256/74/1f/741f082e71c0f0ec58926130be6d55291e029feb13a95acd0cb025904b33db95 (from https://www.govinfo.gov/content/pkg/FR-2015-06-08/pdf/2015-13742.pdf)
- Federal Register: https://www.federalregister.gov/documents/2015/06/08/2015-13742/airworthiness-directives-pratt-and-whitney-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0F3BD0EE4CFC0C1B86257E5E004B751F.0001
- Page: https://openairdocs.org/proposed/FAA-2015-0869

## Summary

We propose to adopt a new airworthiness directive (AD) for all Pratt & Whitney (PW) PW4164, PW4168, PW4168A, PW4164-1D, PW4168-1D, PW4168A-1D, and PW4170 turbofan engines. This proposed AD was prompted by crack finds in the 6th stage low-pressure turbine (LPT) disk. This proposed AD would require removal of affected 6th stage LPT disks. We are proposing this AD to prevent failure of the 6th stage LPT disk, which could lead to an uncontained disk release, damage to the engine, and damage to the airplane.

## Notices in this docket

- Jun 8, 2015: Notice of proposed rulemaking (NPRM). (first notice), FR document 2015-13742, comments due Aug 7, 2015 (https://www.federalregister.gov/documents/2015/06/08/2015-13742/airworthiness-directives-pratt-and-whitney-turbofan-engines)

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