1、Lessons Learned Entry: 0186Lesson Info:a71 Lesson Number: 0186a71 Lesson Date: 1992-10-29a71 Submitting Organization: KSCa71 Submitted by: David PenningtonSubject: Intertank Access Arm. Description of Driving Event: There are no limit switches to prevent the ET intertank access arm from overrunning
2、its extended position should the hydraulics system fail or the snubbers not stop the arm during extension. The mechanical snubbers were not meant to absorb the loads available from the hydraulic system or, more significantly, from the momentum of the arm. This could damage the external tank.Lesson(s
3、) Learned: Lack of limit switches could allow the arm to damage the ET during a hydraulics system failure.Recommendation(s): Design and install emergency stop limit switches that will automatically stop the arm during an inadvertent failure of the drive system.Evidence of Recurrence Control Effectiv
4、eness: 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 Flight Equipmenta71 Ground Operationsa71 Hardwarea71 Launch ProcessAdditional 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-,-,-
