Airworthiness Directives; Allison Engine Company, Inc AE 2100A and AE 2100C Series Turboprop Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to Allison Engine Company, Inc AE 2100A and AE 2100C series turboprop engines. This action requires initial and repetitive visual inspections of the propeller gearbox (PGB) and power section (P/ S) strut fittings for notches and cracks, and, if necessary, replacement with serviceable parts. In addition, this action requires removing and replacing strut fittings as well as reworking them to the latest configuration identified by a new part number (P/N). This amendment is prompted by reports of P/S strut fitting notches and cracks. The actions specified in this AD are intended to prevent PGB and P/S strut fitting cracks, which could result in PGB misalignment, in-flight engine shutdown, and possible loss of the propeller.