Summary
We propose to adopt a new airworthiness directive (AD) for certain Model MD-90-30 airplanes. This proposed AD would require inspecting for corrosion of the retract cylinder support fitting for the main landing gear (MLG) and the mating bore for the support fitting in the MLG trunnion fitting and performing corrective actions if necessary, and replacing cadmium-plated retract cylinder support bushings and bearings. This proposed AD results from reports of the retract cylinder support fitting for the MLG failing during gear extension and subsequently damaging the hydraulic system. We are proposing this AD to prevent corrosion and damage that could compromise the integrity of the retract cylinder support fitting for the MLG, which could adversely affect the airplane's safe landing.