1、Lessons Learned Entry: 1162Lesson Info:a71 Lesson Number: 1162a71 Lesson Date: 2001-02-01a71 Submitting Organization: HQa71 Submitted by: David M. LengyelSubject: Space Shuttle Program/Orbiter/Redundant Hydraulic Lines Description of Driving Event: Potential Common Mode Failure Potential for Hydraul
2、ic Lines in Close Proximity to Each OtherLesson(s) Learned: Redundant hydraulic lines for the three orbiter hydraulic systems are not adequately separated to preclude loss of all hydraulic power in the event of a single catastrophic failure of adjacent hardware.Recommendation(s): Provide the same de
3、gree of separation of redundant critical hydraulic lines as is given to redundant critical electrical wiring.Evidence of Recurrence Control Effectiveness: Code M - Concur: Orbiter hydraulic systems utilize and will continue to implement the same considerations and degree of redundant system separati
4、on as is given redundant critical electrical wiring. Primary consideration is system placement such that a single catastrophic failure environment does not exist. Emphasis is placed on precluding events that may propagate from one function to another. Hazards associated with arc tracking can propaga
5、te to another wire in close proximity and therefore have influenced electrical wiring physical separation requirements. Hydraulic line hazards such as leakage or rupture cannot propagate to an adjacent hydraulic line. Extensive Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) and Ha
6、zard Analyses of the Orbiter systems and operational environment have not identified any credible single failure modes, which would result in the loss of hydraulic power. Neither system is protected against extreme externally induced events such as those that DOD separation requirements address.Prov
7、ided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Aerospace Safety Advisory Panela71 Flight Operationsa71 Risk Management/Assessmenta71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 2002-03-18a71 Approval Name: Bill Loewya71 Approval Organization: HQa71 Approval Phone Number: 202-358-0528Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
