1、Lessons Learned Entry: 0223Lesson Info:a71 Lesson Number: 0223a71 Lesson Date: 1993-06-18a71 Submitting Organization: LERCa71 Submitted by: S. PapellSubject: Cable Pulley Assemblies Description of Driving Event: A counterbalance cable had become disengaged from the upper support beam pulley during a
2、ssembly operations. This was caused by the work scaffold (used to access the upper beam area) making contact with the counterweight. The tension in the cable was relieved, allowing it to slip from the pulley groove. When the load was reestablished, tension was reapplied to the counterbalance cable,
3、pulling the weight free and allowing it to fall.Lesson(s) Learned: Counterbalance cables on single flange mount pulley systems can be dislodged easily from the pulley by physical contact on the counterweight.Recommendation(s): Install pulley assemblies with double flanges to prevent cable from being
4、 dislodged during assembly or maintenance operations.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Mission Directorate(s): N/AAdditional Key Phrase(s): a71 Ground Equipmenta71 Lifting DevicesAdditional Info: Approval Info: a71 Approval Date: 1994-04-19a71 Approval Name: Maria Havenhilla71 Approval Organization: LERC/EBASa71 Approval Phone Number: 216-977-1483Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
