# Proposed AD 98-ANE-69-AD: CFE Company Model CFE738-1-1B Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-23-12
- Action: Supplemental notice of proposed rulemaking; reopening of comment period.
- Published: September 23, 1999, 64 FR 51484
- Comments due: November 22, 1999
- Became: [AD 2000-23-12](https://openairdocs.org/ad/2000-23-12)
- Docket: 98-ANE-69-AD
- FR document: 99-24787
- Official PDF: https://openairdocs.org/files/sha256/10/c1/10c1064281aa1f9035959c40c896998448f6f36284519dcd47c550a40d7371af (from https://www.govinfo.gov/content/pkg/FR-1999-09-23/pdf/99-24787.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/09/23/99-24787/airworthiness-directives-cfe-company-model-cfe738-1-1b-turbofan-engines
- Page: https://openairdocs.org/proposed/98-ANE-69-AD

## Summary

This notice revises an earlier proposed airworthiness directive (AD), applicable to CFE Company model CFE738-1-1B turbofan engines, that would have required a one-time dimensional inspection of the curvic coupling tooth profile of certain high pressure compressor (HPC) rotor components to check for machining mismatches in the curvic coupling in specific engines and, if necessary, replacement with serviceable parts. That proposal was prompted by reports of machining mismatches in certain HPC rotor components that may decrease the service life of these HPC parts. This action, based on subsequent material stress testing and analysis by CFE Company, revises the proposed rule by eliminating the dimensional inspection requirement and imposing new, reduced life limits for certain HPC rotor components in all engines. The actions specified by this proposed AD are intended to prevent failure of certain HPC rotor components, which could result in an uncontained engine failure and damage to the airplane.

## Notices in this docket

- Dec 14, 1998: Notice of proposed rulemaking (NPRM). (first notice), FR document 98-33026, comments due Feb 12, 1999 (https://www.federalregister.gov/documents/1998/12/14/98-33026/airworthiness-directives-cfe-company-model-cfe738-1-1b-turbofan-engines)
- Sep 23, 1999: Supplemental notice of proposed rulemaking; reopening of comment period., FR document 99-24787, comments due Nov 22, 1999 (https://www.federalregister.gov/documents/1999/09/23/99-24787/airworthiness-directives-cfe-company-model-cfe738-1-1b-turbofan-engines)

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