# Proposed AD FAA-2008-0589: Pratt & Whitney (P&W) PW4000 Series 94- Inch Fan Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2008-24-13
- Products: Pratt & Whitney
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: August 14, 2008, 73 FR 47561
- Comments due: September 15, 2008
- Became: [AD 2008-24-13](https://openairdocs.org/ad/2008-24-13)
- Docket: FAA-2008-0589 (https://www.regulations.gov/docket/FAA-2008-0589, where comments are filed)
- Project: 2008-NE-17-AD
- FR document: E8-18811
- Official PDF: https://openairdocs.org/files/sha256/99/69/9969f447c93e7757b992f10538d25ee5aa27286dc7f4013b9bf523831b1f3304 (from https://www.govinfo.gov/content/pkg/FR-2008-08-14/pdf/E8-18811.pdf)
- Federal Register: https://www.federalregister.gov/documents/2008/08/14/E8-18811/airworthiness-directives-pratt-and-whitney-pandw-pw4000-series-94-inch-fan-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F8F21F37E7B96883862574A50046BF92.0001
- Page: https://openairdocs.org/proposed/FAA-2008-0589

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for P&W PW4052, PW4056, PW4060, PW4062, PW4152, PW4156A, PW4158, PW4460, and PW4462 turbofan engines. This proposed AD would require a onetime visual inspection of all EEC-131 model electronic engine controls (EECs). This proposed AD would require the EECs to be identified, categorized by group number, marked, and replaced using a fleet management plan. This proposed AD results from a report of an uncommanded engine in-flight shutdown due to defective EEC pulse width modulator (PWM) microcircuits. We are proposing this AD to prevent uncommanded in-flight engine shutdowns which could result in loss of thrust and prevent continued safe flight or landing.

## Notices in this docket

- Aug 14, 2008: Notice of proposed rulemaking (NPRM). (first notice), FR document E8-18811, comments due Sep 15, 2008 (https://www.federalregister.gov/documents/2008/08/14/E8-18811/airworthiness-directives-pratt-and-whitney-pandw-pw4000-series-94-inch-fan-turbofan-engines)

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