Summary
This document proposes the adoption of a new airworthiness directive (AD) applicable to Agusta S.p.A. Model A109A and A109A II helicopters. This proposal would require radiographic inspection of the internal surface of each main rotor blade spar (spar) for corrosion. This proposal is prompted by the discovery of corrosion on the internal surfaces of the spar in the area adjacent to the main rotor blade inertia balance weights. The actions specified by the proposed AD are intended to prevent failure of a main rotor blade due to corrosion on the internal surface of the spar and subsequent loss of control of the helicopter.