1、Lessons Learned Entry: 0295Lesson Info:a71 Lesson Number: 0295a71 Lesson Date: 1993-07-29a71 Submitting Organization: JSCa71 Submitted by: S. MartinSubject: Manufacturing Defects (Burrs) Becoming Loose Particles and Jamming Meshing Parts of Critical Components (Orbiter Hydraulic Pump) Description of
2、 Driving Event: During the shuttle STS-4 mission, an orbiter (OV-102) hydraulic pump failed. A post flight examination discovered an aluminum particle wedged into one of the high pressure pump gears. The probable source of the particle was determined to be in some drilled oil passages where evidence
3、 of burrs were found at the intersection of the holes. The pump manufacturer:1. Implemented requirements for an inspection of all oil passages prior to assembly.2. Added a flushing of the pump with clean hydraulic fluid following vibration testing and before continuing further acceptance testing.3.
4、Reviewed the pump cleaning process.Lesson(s) Learned: Burrs left remaining during manufacturing processes can become loose particles, migrate into meshing machine parts, and cause operational failures to critical components (orbiter hydraulic pump).Recommendation(s): Inspections for burrs, improved
5、cleaning methods, and flushing of the pumps were added to the manufacturing processes.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): N/AAddition
6、al Key Phrase(s): a71 Hardwarea71 Industrial Operationsa71 Parts Materials & ProcessesAdditional Info: Approval Info: a71 Approval Date: 1993-09-13a71 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-,-,-
