# Proposed AD 98-ANE-51-AD: General Electric Company GE90 Series Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-03-02
- Action: Notice of proposed rulemaking (NPRM).
- Published: November 26, 1999, 64 FR 66415
- Comments due: December 27, 1999
- Became: [AD 2000-03-02](https://openairdocs.org/ad/2000-03-02)
- Docket: 98-ANE-51-AD
- FR document: 99-30804
- Official PDF: https://openairdocs.org/files/sha256/f0/d8/f0d8bc445e763acd55350c768bf2d9af9714fbed918e1f98e0e0400acd36d83d (from https://www.govinfo.gov/content/pkg/FR-1999-11-26/pdf/99-30804.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/11/26/99-30804/airworthiness-directives-general-electric-company-ge90-series-turbofan-engines
- Page: https://openairdocs.org/proposed/98-ANE-51-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain General Electric Company (GE) GE90 series turbofan engines. This proposal would reduce the cyclic life limits for certain mid fan shafts with undesirable microstructure, and remove from service those mid fan shafts prior to exceeding the new limits and replace with serviceable parts. Reports of magnetic particle inspections conducted by the manufacturer identifying segregation in the raw material, resulting in lower fatigue life properties, prompted this proposal. The actions specified by the proposed AD are intended to prevent mid fan shaft failure, which could result in an uncontained engine failure and damage to the aircraft.

## Notices in this docket

- Nov 26, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-30804, comments due Dec 27, 1999 (https://www.federalregister.gov/documents/1999/11/26/99-30804/airworthiness-directives-general-electric-company-ge90-series-turbofan-engines)

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