# Proposed AD 97-NM-63-AD: de Havilland Model DHC-8-100, -200, and -300 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 97-20-10
- Action: Notice of proposed rulemaking (NPRM).
- Published: July 22, 1997, 62 FR 39194
- Comments due: August 29, 1997
- Became: [AD 97-20-10](https://openairdocs.org/ad/97-20-10)
- Docket: 97-NM-63-AD
- FR document: 97-19141
- Official PDF: https://openairdocs.org/files/sha256/e9/2b/e92beeda03dfacabf825db17784ab02ef5b0efd3100f8b0af8f8822ca67c87d8 (from https://www.govinfo.gov/content/pkg/FR-1997-07-22/pdf/97-19141.pdf)
- Federal Register: https://www.federalregister.gov/documents/1997/07/22/97-19141/airworthiness-directives-de-havilland-model-dhc-8-100--200-and--300-series-airplanes
- Page: https://openairdocs.org/proposed/97-NM-63-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain de Havilland Model DHC-8- 100, -200, and -300 series airplanes. This proposal would require modification of the attitude and heading reference systems (AHRS). This proposal is prompted by a report of loss of power to both AHRS's during flight due to a faulty terminal block to which the signal ground for the AHRS's are connected. The actions specified by the proposed AD are intended to prevent simultaneous power loss to both AHRS's, which could result in reduced controllability of the airplane.

## Notices in this docket

- Jul 22, 1997: Notice of proposed rulemaking (NPRM). (first notice), FR document 97-19141, comments due Aug 29, 1997 (https://www.federalregister.gov/documents/1997/07/22/97-19141/airworthiness-directives-de-havilland-model-dhc-8-100--200-and--300-series-airplanes)

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