# Airworthiness Directives; Turbomeca S.A. Turboshaft Engines
> **Rule** · Final rule. · Published 2013-04-23 · Effective 2013-05-28 · 78 FR 23830
## Document
- **Document number:** 2013-09349
- **Category:** airworthiness
- **Manufacturer:** Turbomeca S.A. Turboshaft
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 78 FR 23830
- **Publication date:** 2013-04-23
- **Effective date:** 2013-05-28
## Abstract

We are adopting a new airworthiness directive (AD) for certain Turbomeca S.A. Arriel 1A1, 1A2, 1B, 1C, 1C1, 1C2, 1D, 1D1, 1E2, 1K1, 1S, and 1S1 turboshaft engines. This AD requires daily post-flight checks of the engine tachometer's unit cycle-counting feature. This AD also requires ground-run functional checks within every 1,000 operating hours. This AD was prompted by detailed analysis and review of the accuracy of the engine's tachometer cycle-counting feature. We are issuing this AD to prevent uncontained engine failure and damage to the helicopter.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2013/04/23/2013-09349/airworthiness-directives-turbomeca-sa-turboshaft-engines)
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