Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all CASA Model C-212 series airplanes. This proposal would require an initial inspection of the restrictor pistons on the shock absorbers of the left and right main landing gear (MLG) to determine the number and condition of threaded screw pins that are installed; replacement of any discrepant pin; and repetitive inspections of certain pistons. Modification of certain pistons by the installation of two additional pins would terminate these inspections. This proposal is prompted by reports indicating that the threaded screw pin that holds the restrictor piston on the slide tube of the shock absorber has been found to have loosened on some airplanes. The actions specified by the proposed AD are intended to prevent the loss of hydraulic damping in the MLG, due to failure of the screw pins that hold the restrictor pistons on the slide tubes of the shock absorbers, and consequent structural damage to the airplane.