Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for Turbomeca S.A. Arriel 2D turboshaft engines. This AD was prompted by a low fuel pressure event caused by deterioration and a loss of the low- pressure drive function within the hydro-mechanical metering unit (HMU). This AD requires replacing the HMU at a reduced life. We are issuing this AD to prevent an uncommanded in-flight shutdown of the engine, and possible loss of the helicopter.