1、Lessons Learned Entry: 0004Lesson Info:a71 Lesson Number: 0004a71 Lesson Date: 1991-04-19a71 Submitting Organization: JSCa71 Submitted by: T MichaelSubject: Flight Hardware Damage (Tires) due to Ground Test System Operational Conditions Outside of Design Limits Description of Driving Event: On Novem
2、ber 21, 1989 two shuttle orbiter tires skidded sufficiently to cause blowouts following the application of brakes during a ground test at Wright Patterson Air Force Base. The skidding was caused by the brakes locking due to the failure of the anti-skid system. This failure was due to the use of non-
3、flight switching valves as part of the test stand. Additional damage occurred to a hydraulic hose and quick disconnect fitting. An investigation also discovered an error in the abort software and the addition of excessively restrictive non-flight orifices in the brake hydralic lines. All of these fi
4、ndings contributed to the failure.Lesson(s) Learned: Lack of fidelity between ground test system configuration and the flight system configuration can result in costly and damaging test failures to flight hardware during ground testing.Recommendation(s): The test stand configuration was changed to o
5、perationally duplicate the flight system (the switching valves and other hardware and software items). Also a procedural step was added to stop the skidding if it occurs.Evidence of Recurrence Control Effectiveness: Provided by IHSNot for ResaleNo reproduction or networking permitted without license
6、 from IHS-,-,-N/ADocuments Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Sciencea71 Space Operationsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Configuration Managementa71 Ground Operationsa71 Ground Equipmenta71 Test Articlea71 Test Facilitya71 Test & VerificationAdditional 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-,-,-
