Main Landing Gear Hydraulic Actuator Attach Stud PN 67024-1Airight Inc.Stud This photograph shows the broken Main Landing Gear Hydraulic Activator attach stud that was removed from John Fonville’s SX (N5SX). This stud failed while taxiing. You can clearly see a series of ridges or steps in the radius area of the stud below the fracture point. The hole was drilled into the broken stud and threaded to extract the stud from the gear trunnion.