# Proposed AD FAA-2012-0940: Turbomeca S.A. Turboshaft Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2013-01-07
- Products: Turbomeca
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 7, 2013, 78 FR 34284
- Comments due: August 6, 2013
- Became: [AD 2013-01-07](https://openairdocs.org/ad/2013-01-07)
- Docket: FAA-2012-0940 (https://www.regulations.gov/docket/FAA-2012-0940, where comments are filed)
- Project: 2012-NE-26-AD
- FR document: 2013-13509
- Official PDF: https://openairdocs.org/files/sha256/b0/f4/b0f4f635d7bdcf6fcea4a5f811b43c965dd0b3e90e3d55f2ade9a9a3a0f2ea65 (from https://www.govinfo.gov/content/pkg/FR-2013-06-07/pdf/2013-13509.pdf)
- Federal Register: https://www.federalregister.gov/documents/2013/06/07/2013-13509/airworthiness-directives-turbomeca-sa-turboshaft-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/61385CBFE0F2532F86257B8300477BA9.0001
- Page: https://openairdocs.org/proposed/FAA-2012-0940

## Summary

We propose to supersede an existing airworthiness directive (AD) that applies to all Turbomeca S.A. Arriel 2D turboshaft engines. The existing AD currently requires replacing the hydromechanical metering unit (HMU) at a reduced life. Since we issued that AD, further cases of deterioration of HMU rotating components have been reported before the HMU reached the replacement interval in that AD. The proposed AD would maintain the existing AD requirements and would also require inspections of the HMU. We are proposing this AD to prevent an uncommanded in-flight shutdown of the engine, and possible loss of the helicopter.

## Notices in this docket

- Oct 9, 2012: Notice of proposed rulemaking (NPRM). (first notice), FR document 2012-24721, comments due Dec 10, 2012 (https://www.federalregister.gov/documents/2012/10/09/2012-24721/airworthiness-directives-turbomeca-sa-turboshaft-engines)
- Jun 7, 2013: Notice of proposed rulemaking (NPRM)., FR document 2013-13509, comments due Aug 6, 2013 (https://www.federalregister.gov/documents/2013/06/07/2013-13509/airworthiness-directives-turbomeca-sa-turboshaft-engines)

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