Incident Description
A flight crew reported receiving a flap disagree message during the descent and approach to their destination airport. After attempting the associated checklist procedures without success, the crew performed an uneventful abnormal flap landing.
Post-Inspection Findings
A post-incident inspection revealed a failed inboard trailing edge flap drive torque tube coupling. Further investigation identified one similar failure in the fleet, and an examination of the operating 757 fleet discovered numerous occurrences of excessive wear on the aft coupling of the torque tube assembly.
Laboratory Analysis and Manufacturer Actions
Laboratory analysis of the wear and a metallurgical examination led the manufacturer to reduce the recommended maintenance interval and to recommend more frequent visual inspections of the component.