# Proposed AD FAA-2013-0491: Bell Helicopter Textron Canada Limited (Bell) Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2013-20-03
- Products: Bell Helicopter Textron Canada
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 7, 2013, 78 FR 34290
- Comments due: August 6, 2013
- Became: [AD 2013-20-03](https://openairdocs.org/ad/2013-20-03)
- Docket: FAA-2013-0491 (https://www.regulations.gov/docket/FAA-2013-0491, where comments are filed)
- Project: 2008-SW-012-AD
- FR document: 2013-13478
- Official PDF: https://openairdocs.org/files/sha256/99/a1/99a1790f587432a8910512bc90cf45b01905112c1b7f40c9b22dd667f5914168 (from https://www.govinfo.gov/content/pkg/FR-2013-06-07/pdf/2013-13478.pdf)
- Federal Register: https://www.federalregister.gov/documents/2013/06/07/2013-13478/airworthiness-directives-bell-helicopter-textron-canada-limited-bell-helicopters
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CC8EC5775691A7C486257B8300454BD6.0001
- Page: https://openairdocs.org/proposed/FAA-2013-0491

## Summary

We propose to adopt a new airworthiness directive (AD) for certain Bell Model 430 helicopters. This proposed AD would require installing a placard on the instrument panel and revising the limitations section of the rotorcraft flight manual (RFM). This proposed AD is prompted by several incidents of third stage engine turbine wheel failures, which were caused by excessive vibrations at certain engine speeds during steady-state operations. The proposed actions are intended to alert pilots to avoid certain engine speeds during steady-state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter.

## Notices in this docket

- Jun 7, 2013: Notice of proposed rulemaking (NPRM). (first notice), FR document 2013-13478, comments due Aug 6, 2013 (https://www.federalregister.gov/documents/2013/06/07/2013-13478/airworthiness-directives-bell-helicopter-textron-canada-limited-bell-helicopters)

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