# Proposed AD FAA-2010-0866: Bell Helicopter Textron Canada Limited Model 427 Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2011-03-03
- Products: Bell Helicopter Textron Canada
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: August 30, 2010, 75 FR 52912
- Comments due: October 14, 2010
- Became: [AD 2011-03-03](https://openairdocs.org/ad/2011-03-03)
- Docket: FAA-2010-0866 (https://www.regulations.gov/docket/FAA-2010-0866, where comments are filed)
- Project: 2010-SW-065-AD
- FR document: 2010-21582
- Official PDF: https://openairdocs.org/files/sha256/e7/94/e794dd8045e5a7ec8538fb5b8a0e608a63840eba9b9997b996b48ded6dc61ca7 (from https://www.govinfo.gov/content/pkg/FR-2010-08-30/pdf/2010-21582.pdf)
- Federal Register: https://www.federalregister.gov/documents/2010/08/30/2010-21582/airworthiness-directives-bell-helicopter-textron-canada-limited-model-427-helicopters
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4407066FCD48DB338625778F0051762C.0001
- Page: https://openairdocs.org/proposed/FAA-2010-0866

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

Tail rotor driveshaft hanger bearing bracket part number (P/N) 427-044-223-101 has been found cracked due to fatigue. It has been determined that the fatigue cracking was initiated by a tooling mark left during manufacture. The existence of tooling marks on the bracket could lead to bracket failure, loss of tail rotor drive and, consequently, loss of control of the helicopter.

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

## Notices in this docket

- Aug 30, 2010: Notice of proposed rulemaking (NPRM). (first notice), FR document 2010-21582, comments due Oct 14, 2010 (https://www.federalregister.gov/documents/2010/08/30/2010-21582/airworthiness-directives-bell-helicopter-textron-canada-limited-model-427-helicopters)

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