Airworthiness Directives; Aerospace Technologies of Australia, Nomad N22 and N24 Series Airplanes

This amendment supersedes AirworthinessDirective AD 85-21-06 which applies to all AerospaceTechnologies of Australia (ASTA) Nomad N22 and N24 series airplanes and currently requires replacing the attachment fittings of the upper fin rear spar and the fin/horizontal stabilizer. This action requires removing the upper fin to stub fin forward attachment bolts, inspecting the attachment fittings for cracks, and, if no cracks are found, replacing the attachment bolts with bolts of improved design until the life limit of the attachment fittings is reached, at which time the attachment fittings would be replaced with improved attachment fittings. If cracks are found, this AD requires replacing the attachment bolts and attachment fittings. Cracks found in the underhead radius and at the base of the thread of the bolt prompted this action. The actions specified by thisAD are intended to prevent cracking in the upper fin and horizontal stabilizer attachment fittings, which if not corrected, could result in loss of control of the airplane.