Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for certain Turbomeca S.A. Arriel 1E2 turboshaft engines. This AD requires removing the tachometer box on affected engines. This AD was prompted by reports of uncommanded in-flight shutdowns (IFSDs). We are issuing this AD to prevent failure of the tachometer box, which could lead to failure of the engine, IFSD, and loss of control of the helicopter.