Airworthiness Directives; Cessna Aircraft Company Models 421C and 425 Airplanes

概要

This amendment revises Airworthiness Directive (AD) 91-25-08, which currently requires repetitively inspecting both wing front spar upper caps for cracks on certain Cessna Aircraft Company (Cessna) Models 421C and 425 airplanes, and repairing cracks that exceed certain limits. This action provides the option of incorporating a certain wing spar upper cap service kit as either terminating action or as an extension to the repetitive inspections currently required. Wing front spar upper cap cracks at the main landing gear actuating cylinder attachment fitting on three of the affected airplanes prompted this action. The actions specified by this AD are intended to prevent wing failure caused by excessive wing spar cracking.