Airworthiness Directives; Safran Helicopter Engines, S.A. (Formerly Turbomeca S.A.) Turboshaft Engines

We are superseding airworthiness directive (AD) 2016-04-12, that applies to certain Safran Helicopter Engines, S.A. (formerly Turbomeca S.A.) Arriel 2B, 2B1, 2C, 2C1, 2C2, 2D, 2E, 2S1, and 2S2 turboshaft engines. AD 2016-04-12 required spectrometric oil analysis (SOA) inspection of the engine accessory gearbox (AGB), and, depending on the results, removal of the engine AGB. This AD requires initial and repetitive wear inspections of the engine AGB cover. This AD was prompted by a report of an uncommanded in-flight shutdown (IFSD) of an Arriel 2S2 engine caused by rupture of the 41-tooth gear, which forms part of the bevel gear in the engine AGB. We are issuing this AD to correct the unsafe condition on these products.