Airworthiness Directives; Eurocopter France Model AS-350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Model AS-350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N helicopters, that requires inspections of the main gearbox suspension bi-directional cross-beam (cross-beam) for cracks, and replacement of the cross-beam if a crack is found. This amendment is prompted by several reports of cracks in the cross-beam. The actions specified by this AD are intended to provide a terminating action to prevent failure of the cross-beam that could cause the main gearbox to pivot, resulting in severe vibrations and a subsequent forced landing.