# Proposed AD 95-ANE-64: CFM International CFM56-5C Series Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 97-09-02
- Action: Notice of proposed rulemaking (NPRM).
- Published: March 26, 1996, 61 FR 13110
- Comments due: May 28, 1996
- Became: [AD 97-09-02](https://openairdocs.org/ad/97-09-02)
- Docket: 95-ANE-64
- FR document: 96-7243
- Official PDF: https://openairdocs.org/files/sha256/b7/67/b767834d82e76a277c13bc9cfac0e9aca21bd7192ddd20451ae404dca3121df0 (from https://www.govinfo.gov/content/pkg/FR-1996-03-26/pdf/96-7243.pdf)
- Federal Register: https://www.federalregister.gov/documents/1996/03/26/96-7243/airworthiness-directives-cfm-international-cfm56-5c-series-turbofan-engines
- Page: https://openairdocs.org/proposed/95-ANE-64

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to CFM International (CFMI) CFM56- 5C2/G, -5C3/G, and -5C4 series turbofan engines. This proposal would require a reduction of the low cycle fatigue (LCF) retirement lives for certain high pressure turbine rotor (HPTR) front shafts, HPTR front air seals, HPTR disks, booster spools, and low pressure turbine rotor (LPTR) stage 3 disks. This proposal is prompted by the results of a refined life analysis performed by the manufacturer which revealed minimum calculated LCF lives lower than published LCF retirement lives. The actions specified by the proposed AD are intended to prevent an LCF failure of the HPTR front shaft, HPTR front air seal, HPTR disk, booster spool, and LPTR stage 3 disk, which could result in an uncontained engine failure and damage to the aircraft.

## Notices in this docket

- Mar 26, 1996: Notice of proposed rulemaking (NPRM). (first notice), FR document 96-7243, comments due May 28, 1996 (https://www.federalregister.gov/documents/1996/03/26/96-7243/airworthiness-directives-cfm-international-cfm56-5c-series-turbofan-engines)

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