# Airworthiness Directives; Pratt & Whitney PW4000 Series 94-Inch Fan Turbofan Engines
> **Rule** · Final rule. · Published 2008-12-04 · Effective 2009-01-08 · 73 FR 73782
## Document
- **Document number:** E8-28270
- **Category:** airworthiness
- **Manufacturer:** Pratt & Whitney PW4000 Series 94-Inch Fan Turbofan
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 73 FR 73782
- **Publication date:** 2008-12-04
- **Effective date:** 2009-01-08
- **FAA docket:** Docket No. FAA-2008-0589
## Abstract

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

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2008/12/04/E8-28270/airworthiness-directives-pratt-and-whitney-pw4000-series-94-inch-fan-turbofan-engines)
---
*AI Analytics · CC0 1.0*