# Proposed AD FAA-2015-4474: Pratt & Whitney Division Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2016-08-09
- Products: Pratt & Whitney Division
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: December 9, 2015, 80 FR 76400
- Comments due: February 8, 2016
- Became: [AD 2016-08-09](https://openairdocs.org/ad/2016-08-09)
- Docket: FAA-2015-4474 (https://www.regulations.gov/docket/FAA-2015-4474, where comments are filed)
- Project: 2015-NE-34-AD
- FR document: 2015-30948
- Official PDF: https://openairdocs.org/files/sha256/fe/31/fe31019e86cec3dd3c95177391764287243b907ee581b46a4ef5b4370e74d360 (from https://www.govinfo.gov/content/pkg/FR-2015-12-09/pdf/2015-30948.pdf)
- Federal Register: https://www.federalregister.gov/documents/2015/12/09/2015-30948/airworthiness-directives-pratt-and-whitney-division-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B36E626154B74DC086257F1600579612.0001
- Page: https://openairdocs.org/proposed/FAA-2015-4474

## Summary

We propose to adopt a new airworthiness directive (AD) for certain Pratt & Whitney Division (PW) PW4000-94 inch and PW4000-100 inch model turbofan engines. This proposed AD was prompted by a report of a crack find in the high-pressure compressor (HPC) disk. This proposed AD would require performing an ultrasonic inspection (USI) or an eddy current inspection (ECI) of the HPC 10th stage disk. We are proposing this AD to prevent failure of the HPC 10th stage disk, an uncontained disk release, damage to the engine, and damage to the airplane.

## Notices in this docket

- Dec 9, 2015: Notice of proposed rulemaking (NPRM). (first notice), FR document 2015-30948, comments due Feb 8, 2016 (https://www.federalregister.gov/documents/2015/12/09/2015-30948/airworthiness-directives-pratt-and-whitney-division-turbofan-engines)

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