# Proposed AD FAA-2009-0503: Turbomeca S.A. Model Arriel 1B, 1D, and 1D1 Turboshaft Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2010-02-01
- Products: Turbomeca
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 12, 2009, 74 FR 27946
- Comments due: July 13, 2009
- Became: [AD 2010-02-01](https://openairdocs.org/ad/2010-02-01)
- Docket: FAA-2009-0503 (https://www.regulations.gov/docket/FAA-2009-0503, where comments are filed)
- Project: 2009-NE-12-AD
- FR document: E9-13850
- Official PDF: https://openairdocs.org/files/sha256/5d/fb/5dfb5ad8c12a8a9298ec92b15f4e21f7ff419a50729a71a3b1f34d527a92f9d5 (from https://www.govinfo.gov/content/pkg/FR-2009-06-12/pdf/E9-13850.pdf)
- Federal Register: https://www.federalregister.gov/documents/2009/06/12/E9-13850/airworthiness-directives-turbomeca-sa-model-arriel-1b-1d-and-1d1-turboshaft-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E2E70FE4A5E72F31862575D300503759.0001
- Page: https://openairdocs.org/proposed/FAA-2009-0503

## 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) 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:

The rupture of the Reduction Gear Box Intermediate Pinion may result in an overspeed of the Power Turbine and, subsequently, an uncommanded engine in-flight shutdown. This could lead to an emergency autorotation landing on a single-engine helicopter.

We are proposing this AD to prevent the rupture of the reduction gear box intermediate pinion, which could result in an overspeed of the power turbine, an uncommanded in-flight shutdown of the engine, and an emergency autorotation landing.

## Notices in this docket

- Jun 12, 2009: Notice of proposed rulemaking (NPRM). (first notice), FR document E9-13850, comments due Jul 13, 2009 (https://www.federalregister.gov/documents/2009/06/12/E9-13850/airworthiness-directives-turbomeca-sa-model-arriel-1b-1d-and-1d1-turboshaft-engines)

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