# Proposed AD FAA-2005-22039: Turbomeca S.A. Arrius 2F Turboshaft Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2005-17-17
- Products: Turbomeca
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: January 22, 2009, 74 FR 3978
- Comments due: March 23, 2009
- Became: [AD 2005-17-17](https://openairdocs.org/ad/2005-17-17)
- Docket: FAA-2005-22039 (https://www.regulations.gov/docket/FAA-2005-22039, where comments are filed)
- Project: 2005-NE-33-AD
- FR document: E9-1186
- Official PDF: https://openairdocs.org/files/sha256/eb/38/eb389d0e4eed045dc921f418da9ea8d69ac40e2597448462a90472db04cbdef8 (from https://www.govinfo.gov/content/pkg/FR-2009-01-22/pdf/E9-1186.pdf)
- Federal Register: https://www.federalregister.gov/documents/2009/01/22/E9-1186/airworthiness-directives-turbomeca-sa-arrius-2f-turboshaft-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3C3B7FB61A1F09A18625754600506287.0001
- Page: https://openairdocs.org/proposed/FAA-2005-22039

## Summary

The FAA proposes to supersede an existing airworthiness directive (AD) for Turbomeca S.A. Arrius 2F turboshaft engines that have not incorporated Turbomeca Modification Tf75. That AD currently requires replacing the O-ring on the check valve piston in the lubrication unit at repetitive intervals. This proposed AD would require the same repetitive replacements and would require incorporating Modification Tf75 as terminating action to the repetitive O-ring replacements. Modification Tf75 replaces the check valve piston with a piston design not requiring an O-ring. This proposed AD results from the European Aviation Safety Agency (EASA) and Turbomeca S.A. mandating the incorporation of Modification Tf75. We are proposing this AD to prevent an uncommanded in-flight shutdown of the engine, which could result in a forced autorotation landing and damage to the helicopter.

## Notices in this docket

- Nov 8, 2006: Notice of proposed rulemaking (NPRM). (first notice), FR document E6-18839, comments due Jan 8, 2007 (https://www.federalregister.gov/documents/2006/11/08/E6-18839/airworthiness-directives-turbomeca-sa-arrius-2f-turboshaft-engines)
- Jan 22, 2009: Notice of proposed rulemaking (NPRM)., FR document E9-1186, comments due Mar 23, 2009 (https://www.federalregister.gov/documents/2009/01/22/E9-1186/airworthiness-directives-turbomeca-sa-arrius-2f-turboshaft-engines)

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