1、Lessons Learned Entry: 0330Lesson Info:a71 Lesson Number: 0330a71 Lesson Date: 1993-06-14a71 Submitting Organization: MSFCa71 Submitted by: White, MargoSubject: Debonding Due to Pressure Trapped in Voids with Subsequent Exposure to External Reduced Pressure Description of Driving Event: KSC post fli
2、ght inspections of RSRM-2 (STS 27) showed a 3.5“ x 3.5“ piece of JPS cork missing from the right hand center field joint at 185 degrees indicating debris. An unbond also existed between the EPDM moisture seal and the extruded cork at this missing location. The missing cork was located at the kevlar
3、band buckle, where the JPS cork interface had been cut to fit over the buckle, creating an unvented void area under the cork.Lesson(s) Learned: Voids in bond lines can result in debonding if a pressure differential is created between the void and the external environment.Recommendation(s): Eliminate
4、 voids in bond lines (as between cork insulation and the substrate) where possible; if not possible, provide vent holes at the void site.Evidence of Recurrence Control Effectiveness: Engineering assessment indicates that provision of vent holes at known void sites would eliminate the possibility of
5、pressure differential causing a debond.Documents Related to Lesson: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Hardwarea71 Parts Materials & ProcessesAdditional Info: Approval Info: a71 Approval Date: 1994-08-17a71 Approval Name: White, Margoa71 Approval Organization: EH44a71 Approval Phone Number: 205-544-4182Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
