Airworthiness Directives; McDonnell Douglas Model MD-90-30 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-90-30 series airplanes, that requires modification of the right and left main landing gear (MLG) hydraulic damper assemblies or replacement of the MLG hydraulic damper assemblies with modified and reidentified hydraulic damper assemblies. This amendment is prompted by reports indicating that, during overhauls, the MLG hydraulic dampers assemblies failed or had damaged spring retainers due to insufficient material thickness of the spring retainers. The actions specified by this AD are intended to prevent failure of the hydraulic damper assemblies of the MLG, which could result in vibration damage and collapse of the MLG.