Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, and -400F series airplanes; and Model 747SR series airplanes. For certain airplanes, this proposal would require repetitive inspections of the clevis bushings on the inboard and outboard sequence carriages of the wing foreflap for bushing migration, and corrective action, if necessary; replacement of existing bushings with new bushings, which would terminate the repetitive inspections; and replacement of the bushing markers with new markers, if necessary, to indicate the correct bushing orientation. For certain other airplanes, this proposal would require a one-time inspection to determine whether the bushings are in the correct orientation, and follow-on actions. This action is necessary to prevent the loss of an inboard trailing edge foreflap during flight, and subsequent damage to the airplanein flight. This action is intended to address the identified unsafe condition.