# Proposed AD FAA-2015-1985: Bombardier, Inc. Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2015-21-02
- Products: Bombardier
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 25, 2015, 80 FR 36493
- Comments due: August 10, 2015
- Became: [AD 2015-21-02](https://openairdocs.org/ad/2015-21-02)
- Docket: FAA-2015-1985 (https://www.regulations.gov/docket/FAA-2015-1985, where comments are filed)
- Project: 2014-NM-214-AD
- FR document: 2015-15505
- Official PDF: https://openairdocs.org/files/sha256/8b/74/8b741d443ab5ac02c572e28111bb3127d3c903852337b6e973eea6f5f176c207 (from https://www.govinfo.gov/content/pkg/FR-2015-06-25/pdf/2015-15505.pdf)
- Federal Register: https://www.federalregister.gov/documents/2015/06/25/2015-15505/airworthiness-directives-bombardier-inc-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4BC747AE6D28D61E86257E6F004D9419.0001
- Page: https://openairdocs.org/proposed/FAA-2015-1985

## Summary

We propose to adopt a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 airplanes. This proposed AD was prompted by reports of un-annunciated failures of the direct current (DC) starter generator, which caused caution indicators of the affected systems to illuminate and prompted emergency descents and landings. This proposed AD would require, for certain airplanes, replacing the DC generator control units (GCUs) with new GCUs and replacing the GCU label. We are proposing this AD to prevent a low voltage condition on the left main DC bus which, during critical phases of flight, could result in the loss of flight management, navigation, and transponder systems, and could affect continued safe flight.

## Notices in this docket

- Jun 25, 2015: Notice of proposed rulemaking (NPRM). (first notice), FR document 2015-15505, comments due Aug 10, 2015 (https://www.federalregister.gov/documents/2015/06/25/2015-15505/airworthiness-directives-bombardier-inc-airplanes)

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