# Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines
> **Rule** · Final rule, request for comments. · Published 2001-03-15 · Effective 2001-03-30 · 66 FR 15024
## Document
- **Document number:** 01-6300
- **Category:** airworthiness
- **Manufacturer:** Pratt & Whitney PW4000 Series Turbofan
- **Type:** Rule
- **Action:** Final rule, request for comments.
- **Citation:** 66 FR 15024
- **Publication date:** 2001-03-15
- **Effective date:** 2001-03-30
- **FAA docket:** Docket No. 2000-NE-43-AD
## Abstract

This amendment supersedes airworthiness directive (AD) 2000- 25-06, dated December 5, 2000, that is applicable to certain Pratt & Whitney (PW) PW4000 turbofan engines with the current design low pressure turbine (LPT) 4th stage air seal installed. That AD currently requires, based on engine model, replacement of the current design seal with a new design seal, or with a modified seal. This amendment adds the listing of certain engine serial numbers, to correct an error in the applicability section of AD 2000-25-06, for engines affected by PW Service Bulletin (SB) PW4 ENG 72-657, Revision 1, dated July, 19, 2000. This correction is prompted by comments received on AD 2000-25-06. The actions specified by this AD are intended to reduce stresses that could lead to LPT 4th stage air seal cracking, resulting in seal fracture, uncontained engine failure, and damage to the airplane.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2001/03/15/01-6300/airworthiness-directives-pratt-and-whitney-pw4000-series-turbofan-engines)
---
*AI Analytics · CC0 1.0*