# Airworthiness Directives; CFM International CFM56-5B/2P Series Turbofan Engines
> **Rule** · Final rule. · Published 1998-01-21 · Effective 1998-03-23 · 63 FR 3031
## Document
- **Document number:** 98-1326
- **Category:** airworthiness
- **Manufacturer:** CFM International CFM56-5B/2P Series Turbofan
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 63 FR 3031
- **Publication date:** 1998-01-21
- **Effective date:** 1998-03-23
- **FAA docket:** Docket No. 97-ANE-29-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to CFM International (CFMI) CFM56-5B/2P series turbofan engines, that requires a reduction of the low cycle fatigue (LCF) retirement life for certain low pressure turbine (LPT) cases. This amendment is prompted by the results of a refined life analysis performed by the manufacturer which revealed minimum calculated LCF lives significantly lower than the published LCF retirement life. The actions specified by this AD are intended to prevent a LCF failure of the LPT case, which could result in damage to the aircraft.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1998/01/21/98-1326/airworthiness-directives-cfm-international-cfm56-5b2p-series-turbofan-engines)
---
*MORVS · CC0 1.0*