# Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-145 Series Airplanes
> **Rule** · Final rule; request for comments. · Published 1999-01-29 · Effective 1999-02-02 · 64 FR 4521
## Document
- **Document number:** 99-1980
- **Category:** airworthiness
- **Manufacturer:** Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-145 Series
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 64 FR 4521
- **Publication date:** 1999-01-29
- **Effective date:** 1999-02-02
- **FAA docket:** Docket No. 98-NM-386-AD
## Abstract

This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 99-01-12 that was sent previously to all known U.S. owners and operators of certain EMBRAER Model EMB-145 series airplanes by individual notices. This AD requires revisions to the Airplane Flight Manual to provide the flight crew with updated procedures for prohibiting use of the autopilot below 1,500 feet above ground level, emergency procedures for pitch trim runaway, and abnormal procedures for autopilot trim failure and stabilizer out of trim. This AD also requires installation of certain warning placards. This action is prompted by a report indicating that, during a flight test of a similar airplane model, the pitch trim monitoring subsystem malfunctioned internally. The actions specified by this AD are intended to prevent failure of the pitch trim system, which could cause undetected autopilot trim runaway, and consequent reduced controllability of the airplane, uncommanded autopilot disconnect, and excessive altitude loss.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/01/29/99-1980/airworthiness-directives-empresa-brasileira-de-aeronautica-sa-embraer-model-emb-145-series-airplanes)
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