# Airworthiness Directives; General Electric Aircraft Engines CF34 Series Turbofan Engines
> **Rule** · Final rule. · Published 1999-10-26 · Effective 1999-12-27 · 64 FR 57556
## Document
- **Document number:** 99-27788
- **Category:** airworthiness
- **Manufacturer:** General Electric
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 57556
- **Publication date:** 1999-10-26
- **Effective date:** 1999-12-27
- **FAA docket:** Docket No. 98-ANE-62-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain General Electric Aircraft Engines CF34 series turbofan engines, that establishes new life limits for certain high pressure compressor (HPC) spools, stage 9 HPC disks, and rear HPC spools. This amendment is prompted by a cyclic life analysis using increased stress levels resulting from manufacturing discrepancies. The actions specified by this AD are intended to prevent HPC spool and disk cracking, which could result in an uncontained engine failure and damage to the aircraft.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/10/26/99-27788/airworthiness-directives-general-electric-aircraft-engines-cf34-series-turbofan-engines)
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