# Proposed AD FAA-2007-28077: Turbomeca S.A. Arriel 2B and 2B1 Turboshaft Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2009-09-03
- Products: Turbomeca
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: May 12, 2010, 75 FR 26681
- Comments due: June 28, 2010
- Became: [AD 2009-09-03](https://openairdocs.org/ad/2009-09-03)
- Docket: FAA-2007-28077 (https://www.regulations.gov/docket/FAA-2007-28077, where comments are filed)
- Project: 2007-NE-20-AD
- FR document: 2010-11324
- Official PDF: https://openairdocs.org/files/sha256/9a/fe/9afe53a7be8441d2c8828243f929db707ed4ae68fe7f1cf025c4519405ac0e6f (from https://www.govinfo.gov/content/pkg/FR-2010-05-12/pdf/2010-11324.pdf)
- Federal Register: https://www.federalregister.gov/documents/2010/05/12/2010-11324/airworthiness-directives-turbomeca-sa-arriel-2b-and-2b1-turboshaft-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8B78D070398E00B986257721004EACC7.0001
- Page: https://openairdocs.org/proposed/FAA-2007-28077

## Summary

We propose to revise an existing airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued 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: Since issuance of AD 2007-0109, Turbom[eacute]ca has released modification TU166 which consists in inserting HP blade dampers between the HP disc and the HP blade platform. Introduction of these dampers has demonstrated to limit axial displacement of the HP blade relative to the disk in case of blade lock rupture or opening, therefore eliminating the need for inspection and replacement. We are proposing this AD to prevent an uncommanded in-flight engine shutdown which could result in an emergency autorotation landing or an accident.

## Notices in this docket

- Dec 9, 2008: Notice of proposed rulemaking (NPRM). (first notice), FR document E8-29102, comments due Jan 8, 2009 (https://www.federalregister.gov/documents/2008/12/09/E8-29102/airworthiness-directives-turbomeca-sa-arriel-2b-2b1-and-2b1a-turboshaft-engines)
- May 12, 2010: Notice of proposed rulemaking (NPRM)., FR document 2010-11324, comments due Jun 28, 2010 (https://www.federalregister.gov/documents/2010/05/12/2010-11324/airworthiness-directives-turbomeca-sa-arriel-2b-and-2b1-turboshaft-engines)

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