AD 2011-26-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Aviat | Various | Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft Engines |
| engine | Turbomeca | Arriel 1 Series | Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft Engines |
Unsafe Condition
Failure of the gas generator (GG) second stage turbine disc which could result in the release of high energy debris and damage to the helicopter.
Required Actions
Remove from service the GG second stage turbine discs, part number (P/N) 0 292 25 040 0, that do not have the ``CFR'' marking before exceeding 4,000 cycles-in-service (CIS) since-new. Remove from service gas generator second stage turbine discs, P/N 0 292 25 040 0, that have the ``CFR'' marking before exceeding 6,500 CIS since-new. Do not install into any engine gas generator second stage turbine discs, P/N 0 292 25 040 0, that do not have the ``CFR'' marking and have 4,000 or more CIS since-new. Do not install into any engine gas generator second stage turbine discs, P/N 0 292 25 040 0, that have the ``CFR'' marking and have 6,500 or more CIS since-new.
Compliance Time
Within 50 flight hours
Affected Aircraft
Turbomeca Arriel 1A, 1A1, 1B, 1C, 1C1, 1C2, 1D, 1D1, and 1S1 turboshaft engines that have incorporated Modification TU347.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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