AD 2017-05-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Safran | Helicopter | Airworthiness Directives; Safran Helicopter Engines, S.A. Turboshaft Engines |
Unsafe Condition
Low returning spring rate of the needle of the hydro-mechanical metering unit (HMU), which enables needle oscillation during rapid engine deceleration, leading to uncommanded in-flight shutdown (IFSD).
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove any pre-modification (mod) TU 158 HMU and replace it with a part eligible for installation, as specified in Safran Helicopter Engines, S.A. Mandatory Service Bulletin No. 292 73 3158, Version A, dated April 7, 2016, or other FAA-approved parts.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 200 engine hours, or within 5 months, whichever occurs first after the effective date of this AD.
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Affected Aircraft
All Safran Helicopter Engines, S.A. Arriel 2B turboshaft engines with a pre-modification (mod) TU 158 hydro-mechanical metering unit (HMU), installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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