Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 737-100, -200, -300, -400, and -500 series airplanes. This action requires a one-time inspection to verify correct installation of the fastener that connects the input rod of the spoiler mixer mechanism to the torque tube crank, and corrective actions, if necessary. For certain airplanes, this action requires replacement of the nut, bolt, and cotter pin that connects the input rod of the spoiler mixer mechanism to the torque tube crank with a new or serviceable nut, bolt, and cotter pin. This amendment is prompted by reports indicating numerous discrepancies in the installation of the fastener that connects the input rod of the spoiler mixer mechanism to the torque tube crank. The actions specified in this AD are intended to prevent the linkage between the ratio changer input rod and the aft aileron control quadrant from becoming disconnected, which could result in reduced controllability of the airplane.