Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

We are superseding an existing airworthiness directive (AD) for all Turbomeca S.A. Arriel 1E2, 1S, and 1S1 turboshaft engines. That AD currently requires a one-time inspection and torque check of the 3- way union plug installed on all fuel control units (FCUs). This new AD requires the same actions. This AD also requires reduction of the applicability to certain FCUs and references an updated service bulletin containing additional detailed information to identify the non-compliant "red disk." This AD also requires replacement of the plug before further flight if it is found to be non-compliant, and prohibits installation of FCUs that have not passed the 3-way union plug inspection and torque check. This AD was prompted by Turbomeca S.A. informing us that FCUs manufactured, repaired, or overhauled after March 31, 2008, do not require inspection. We are issuing this AD to prevent fuel leaks, which could result in a fire and damage to the helicopter.