# Airworthiness Directives; CFM International, S.A. Turbofan Engines
> **Rule** · Final rule. · Published 2021-05-20 · Effective 2021-06-24 · 86 FR 27264
## Document
- **Document number:** 2021-10607
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 86 FR 27264
- **Publication date:** 2021-05-20
- **Effective date:** 2021-06-24
- **FAA docket:** Docket No. FAA-2019-0568
## Abstract

The FAA is adopting a new airworthiness directive (AD) for all CFM International, S.A. (CFM) CFM56-5B and CFM56-7B model turbofan engines with a certain high-pressure turbine (HPT) inner stationary seal installed. This AD was prompted by cracks found in the rotating air HPT front seal. This AD requires removal, inspection, and replacement of the affected HPT inner stationary seal and, depending on the findings, replacement of the rotating air HPT front seal, HPT rotor blades, and No. 3 ball bearing. The FAA is issuing this AD to address the unsafe condition on these products.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2021/05/20/2021-10607/airworthiness-directives-cfm-international-sa-turbofan-engines)
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