# Airworthiness Directives; Pratt & Whitney PW4164, PW4168, and PW4168A Series Turbofan Engines
> **Rule** · Final rule; request for comments. · Published 1998-02-26 · Effective 1998-03-13 · 63 FR 9730
## Document
- **Document number:** 98-3799
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 63 FR 9730
- **Publication date:** 1998-02-26
- **Effective date:** 1998-03-13
- **FAA docket:** Docket No. 97-ANE-44-AD
## Abstract

This amendment adopts a new airworthiness directive (AD) that is applicable to Pratt & Whitney PW4164, PW4168, and PW4168A series turbofan engines. This action requires initial and repetitive inspections for loose or broken front pylon mount bolts, replacement, if necessary, with new bolts, and establishment of a new cyclic life limit. This amendment is prompted by new flight test data that indicate higher than predicted loads. The actions specified in this AD are intended to prevent front pylon mount bolt failure, which could result in engine separation from the aircraft.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1998/02/26/98-3799/airworthiness-directives-pratt-and-whitney-pw4164-pw4168-and-pw4168a-series-turbofan-engines)
---
*MORVS · CC0 1.0*