Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2021-02-15, which applies to certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SR series airplanes. AD 2021-02-15 requires repetitive replacement of certain parts; an inspection to determine production configuration for certain parts; repetitive lubrication of certain parts and a repetitive inspection of certain parts for any exuding grease; repetitive inspections of certain parts for loose or missing attachment bolts, cracks or bushing migration, cracks or gouges, or broken, binding, or missing rollers; repetitive inspections of certain parts for cracks or corrosion; repetitive lubrication; and on-condition actions if necessary. Since the FAA issued AD 2021-02-15, the FAA determined that certain compliance times must be reduced in order to address the unsafe condition. This proposed AD would continue to require the actions specified in AD 2021-02-15 with certain reduced compliance times. The FAA is proposing this AD to address the unsafe condition on these products.