# Proposed AD FAA-2009-0227: Bell Helicopter Textron Canada Model 427 Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2009-15-15
- Products: Bell Helicopter Textron Canada
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: March 23, 2009, 74 FR 12098
- Comments due: April 22, 2009
- Became: [AD 2009-15-15](https://openairdocs.org/ad/2009-15-15)
- Docket: FAA-2009-0227 (https://www.regulations.gov/docket/FAA-2009-0227, where comments are filed)
- Project: 2007-SW-65-AD
- FR document: E9-6225
- Official PDF: https://openairdocs.org/files/sha256/6e/52/6e528b0ba55fd5e8cbaeb095998e99cc6fc73749852621d5d3d282507aab6e5c (from https://www.govinfo.gov/content/pkg/FR-2009-03-23/pdf/E9-6225.pdf)
- Federal Register: https://www.federalregister.gov/documents/2009/03/23/E9-6225/airworthiness-directives-bell-helicopter-textron-canada-model-427-helicopters
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/DC2FB2F0C34C7CDC86257582005591C8.0001
- Page: https://openairdocs.org/proposed/FAA-2009-0227

## Summary

We propose to adopt a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 427 helicopters. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by the aviation authority of Canada to identify and correct an unsafe condition on an aviation product. Transport Canada, the aviation authority of Canada, with which we have a bilateral agreement, states that it has been determined that the existing hardware connecting the vertical fin to the tail rotor gearbox needs to be upgraded, to prevent the vertical fin from becoming loose. BHTC has received reports of loose vertical fins discovered during inspections. Investigation revealed that the current vertical fin attachment hardware may not provide adequate clamp-up. If not corrected, the vertical fin could become loose and cause vibration, which could lead to subsequent loss of control of the helicopter. The proposed AD would require actions that are intended toaddress this unsafe condition.

## Notices in this docket

- Mar 23, 2009: Notice of proposed rulemaking (NPRM). (first notice), FR document E9-6225, comments due Apr 22, 2009 (https://www.federalregister.gov/documents/2009/03/23/E9-6225/airworthiness-directives-bell-helicopter-textron-canada-model-427-helicopters)

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