1、Lessons Learned Entry: 0382Lesson Info:a71 Lesson Number: 0382a71 Lesson Date: 1995-02-13a71 Submitting Organization: JPLa71 Submitted by: B.J. WagonerSubject: Magellan Solid Rocket Motor Safe and Arm Device Abstract: Given unclear procedures, had an assembly technician not questioned the assembly o
2、f the SRM Safe and Arm (S&A) devices, the SRM would have failed to ignite at the time of Venus orbit insertion.Recommendations involve providing cognizant personnel, clear procedures, independent checks, and training. Seal unused mechanical or electrical connections. Description of Driving Event: Du
3、ring final preparations for the Magellan launch at Kennedy Space Center, the Solid Rocket Motor (SRM) Explosive Transfer Assembly (ETA) lines were incorrectly assembled to the inert ports of the Safe and Arm (S&A) devices. The assembly error was caused by unclear procedures, an improperly labeled di
4、agram in a field service manual, no cognizant personnel familiar with the S&A device in attendance and inadequate mechanical locking of the plug in the S&A inert port.The assembly technician had second thoughts and concerns over the correctness of the installation. At the manufacturing facility he e
5、xamined the S&A device data package and checked with knowledgeable engineering personnel to verify that the assembly was in error. Had the error not been corrected, the solid rocket motor would have failed to ignite at the time of Venus orbit insertion.Additional Keyword(s): PropulsionLesson(s) Lear
6、ned: Unclear procedures and lack of cognizant technical personnel in attendance can result in incorrect assembly of mission critical mechanical or electrical connections.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Recommendation(s): 1. Cognizant
7、personnel, thoroughly familiar with the hardware, must be involved during the conduct of any critical or hazardous operation.2. Prior to performing any critical or hazardous operation on a spacecraft, procedures must be reviewed for clarity and correctness, and approved by cognizant technical person
8、nel.3. If an assembly operation is untestable for verification, an independent check should be incorporated in the procedure (picture, X-ray, etc.).4. Unused mechanical or electrical connections should be sealed or otherwise protected to avoid misconnection by assembly technicians.5. Personnel invol
9、ved in critical or hazardous operations on a spacecraft must practice the procedures and be qualified by hands-on experience.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Flight Equipmenta71 Ground OperationsAdditional Info: Approval Info: a71 Approval Date: 1989-07-27a71 Approval Name: Carol Dumaina71 Approval Organization: 125-204a71 Approval Phone Number: 818-354-8242Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
