# Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-120RT and -120ER Series Airplanes
> **Rule** · Final rule. · Published 1999-09-15 · Effective 1999-10-20 · 64 FR 49974
## Document
- **Document number:** 99-23473
- **Category:** airworthiness
- **Manufacturer:** Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-120RT and -120ER Series
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 49974
- **Publication date:** 1999-09-15
- **Effective date:** 1999-10-20
- **FAA docket:** Docket No. 98-NM-261-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain EMBRAER Model EMB-120RT and -120ER series airplanes, that requires repetitive detailed visual inspections to detect discrepancies of the brake assemblies on the main landing gear (MLG), and replacement of the brake assemblies with new or serviceable brake assemblies, if necessary. This amendment is prompted by reports of fatigue cracking or splitting of the brake stator disk at the thermal expansion slots. The actions specified by this AD are intended to prevent failure of the brake assemblies of the MLG due to cracking or splitting of the stator disk, which could result in loss of brake effectiveness and could cause the airplane to leave the runway surface.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/09/15/99-23473/airworthiness-directives-empresa-brasileira-de-aeronautica-sa-embraer-model-emb-120rt-and--120er)
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