Airworthiness Directives; Turbomeca S.A. Arriel Models 2 S1, 2 B, and 2 C Turboshaft Engines

This amendment adopts a new airworthiness directive (AD), that is applicable to Turbomeca S.A. Arriel models 2 S1, 2 B, and 2 C turboshaft engines. This amendment requires initial and repetitive visual inspections for fuel leaks, and replacement of fuel pumps that are found leaking fuel. In addition, this amendment requires that fuel pumps found with pump wall thickness below minimum be removed from service. This amendment is prompted by a manufacturing investigation of pump bodies found to have below minimum material thickness, which could cause fuel leakage through thin, porous walls, reducing fuel pump fire resistance. The actions specified by this AD are intended to prevent fuel leakage, which may cause engine fires that could lead to an in- flight engine shutdown, damage to the helicopter, and forced landing.