1、Lessons Learned Entry: 0094Lesson Info:a71 Lesson Number: 0094a71 Lesson Date: 1992-07-30a71 Submitting Organization: KSCa71 Submitted by: David PenningtonSubject: Thruster Purge Operations Description of Driving Event: During removal of the purge adapter from thruster R4D, liquid MMH was observed l
2、eaking from the thruster nozzle. When the leak was discovered the OPF high bay hypergolic exhaust fans were actuated, the high bay evacuated, and fire and medical support were requested to stand by. The leaking MMH was caused by a liquid trap present in the fuel suction hose. The trap was formed by
3、excessive hose length, which was routed to the next level above, then down to the purge adapter. The routing and hose length was left over from a previous operation on the left side of the orbiter.Lesson(s) Learned: Failure to require a specific hose route resulted in a liquid trap being inadvertent
4、ly formed causing liquid MMH to leak from a thruster nozzle.Recommendation(s): Update operational procedures to include a requirement to ensure proper hose configuration and routing prior to beginning purge operations.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AP
5、rovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Mission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Energetic Materials - Explosive/Propellant/Pyrotechnica71 Flight Equipmenta71 Hardwarea71 Launch Vehiclea71 Pressure VesselsAdditional Info: Approval Info: a71 Approval Date: 1994-06-02a71 Approval Name: James G. Klinea71 Approval Organization: KSC/HEIa71 Approval Phone Number: 407-867-7614Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
