1、Lessons Learned Entry: 0007Lesson Info:a71 Lesson Number: 0007a71 Lesson Date: 1991-04-29a71 Submitting Organization: JSCa71 Submitted by: Leroy UnderwoodSubject: Debonding of a Mounting Device (Shuttle Orbiter TV Monitor Bracket) due to Growth of a Pressurized Vessel such as the Crew Cabin Wall Fol
2、lowing Launch Description of Driving Event: During two successive missions of the shuttle orbiter OV-99, a television monitor secured by a bracket that was bonded to the wall of the crew module, became detached from the wall (debonded). Following the first incident, it was assumed that an improper b
3、onding technique was the cause of the failure. Remounting was accomplished under close surveillance by quality inspectors. Following the second incident, it was concluded that growth of the structural skin of the wall due to pressurization during flight caused the failure. It was explained that this
4、 did not occur on orbiter OV-102 because its wall is thicker and subject to less growth from pressurization. An object as large as a TV monitor detaching from its mount during any phase of a mission could become a hazard to personnel or equipment. The wall section of OV-99 used for mounting the moni
5、tor was stiffened with wall doublers to reduce growth from pressurization during launch.Lesson(s) Learned: Deformation or growth of base material (wall of orbiter crew cabin) from pressurization can cause debonding of hardware attached with adhesives.Recommendation(s): Stiffeners were added to a sec
6、tion of the crew cabin wall to reduce the growth effects from pressurization.Evidence of Recurrence Control Effectiveness: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operations
7、a71 Exploration SystemsAdditional Key Phrase(s): a71 Flight Operationsa71 Flight Equipmenta71 Hardwarea71 Launch Vehiclea71 Parts Materials & Processesa71 Pressure VesselsAdditional Info: Approval Info: a71 Approval Date: 1993-09-09a71 Approval Name: Ron Montaguea71 Approval Organization: JSC/NS3a71 Approval Phone Number: 281-483-8576Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
