1、Lessons Learned Entry: 0174Lesson Info:a71 Lesson Number: 0174a71 Lesson Date: 1992-10-22a71 Submitting Organization: KSCa71 Submitted by: David PenningtonSubject: OPF Payload Bay Buckets. Description of Driving Event: The OPF payload bay bridge hoist system spans the length of the shuttle payload b
2、ay. Two bridges, mounted on platforms, move on rails. On each bridge are two moveable trolleys, each trolley providing a base for a suspended, telescoping bucket hoist. Each trolley has two-speed (3 ft/min and 9 ft/min), direct-drive gear motors and redundant electric brakes. There is potential for
3、flight hardware damage because the bridge cannot stop in short distances.Lesson(s) Learned: There are no brakes on the bridge bucket drive units to ensure the bridge will stop if the drive chain or the electric brake fails.Recommendation(s): Design a fail safe braking system that will include the br
4、idge drive unit and prevent the bucket from colliding with flight hardware.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/AMission Directorate(s): N/AAdditional Key Phra
5、se(s): a71 Facilitiesa71 Lifting DevicesAdditional Info: Approval Info: a71 Approval Date: 1994-06-06a71 Approval Name: James G. Klinea71 Approval Organization: KSC/HEIa71 Approval Phone Number: 407-867-7614Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
