Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800 and -900 Series Airplanes

摘要

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes. This proposed AD would require repetitive lubrication of the left and right main landing gear (MLG) forward trunnion pins. This proposed AD would also require an inspection for discrepancies of the transition radius of the MLG forward trunnion pins, and repair or replacement if necessary. This proposed AD would also require a one- time inspection for discrepancies of the lead-in chamfer and cross-bolt bore, and repair or replacement if necessary. Doing the applicable inspections and repairs/replacements, or overhauling the trunnion pins ends the repetitive lubrication requirements of this proposed AD. This proposed AD results from a report that the protective finishes on the forward trunnion pins for the left and right MLG might have been damaged during final assembly. We are proposing this AD to prevent cracking of the forward trunnion pin, which could result in fracture of the pin and consequent collapse of the MLG.