Airworthiness Directives; The Boeing Company Airplanes

The FAA is superseding Airworthiness Directive (AD) 2021-02- 15, which applied 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 required 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. This AD was prompted by the FAA's determination that certain compliance times must be reduced in order to address the unsafe condition. This AD continues to require the actions specified in AD 2021-02-15 with certain reduced compliance times. The FAA is issuing this AD to address the unsafe condition on these products.