Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, - 30, -40, and -50 Series Airplanes and C-9 (Military) Airplanes

摘要

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 series airplanes, that requires either replacement or modification of the hydraulic damper assembly. This amendment is prompted by reports indicating that insufficient damping of the hydraulic shimmy damper in the main landing gear (MLG) can allow high torsional vibration to occur. The actions specified by this AD are intended to prevent such vibration, which can damage the MLG assembly and lead to its collapse.