Airworthiness Directives; Agusta S.p.A. Model A109C and A109K2 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Agusta S.p.A. Model A109C and A109K2 helicopters. This amendment requires removing the main rotor pitch link assemblies, measuring the radial play of the upper and lower spherical bearings (bearings), and replacing any unairworthy bearings. This amendment is prompted by four reports of increased vibration of the helicopters caused by wear in the bearings of the main rotor pitch change link assembly. The actions specified by this AD are intended to detect unairworthy bearings on the pitch change link assembly and to prevent increased vibration and subsequent reduced controllability of the helicopter.