Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes. This proposal would require installation of hydraulic line restrictors in the main landing gear (MLG), and modification of the hydraulic damper assembly of the MLG. This proposal is prompted by reports of vibration occurring in the MLG during landing; in some cases, such vibration has led to the collapse of the MLG. The actions specified by the proposed AD are intended to prevent incidents of vibration in the MLG, which can adversely affect the integrity of the MLG.