1、Lessons Learned Entry: 1602Lesson Info:a71 Lesson Number: 1602a71 Lesson Date: 2005-06-02a71 Submitting Organization: DFRCa71 Authored by: Jonathan BrownSubject: Fin Actuator System (FAS) Redesign Implementation/Spares Abstract: Following the recommendations from the X43A Flight 1 MIB, the Pegasus a
2、ctuator system was redesigned to accommodate the need for greater hinge torque. The analog-based legacy actuator system was redesigned for digital drive of the power output stage to the actuators, an additional actuator was incorporated to provide the necessary torque including margins, and the powe
3、r supply was increased to provide the required 80+ amps, instead of the previous 40 amp capability. Multiple failures during qualification testing, and the subsequent technical investigations, proved the lack of understanding between the ideal circuit operation and the impact of system implementatio
4、n. Low-inductance ground and power planes/paths within (sub)systems are essential for proper operation. Description of Driving Event: Following the recommendations from the X43A Flight 1 MIB, the Pegasus actuator system was redesigned to accommodate the need for greater hinge torque. The analog-base
5、d legacy actuator system was redesigned for digital drive of the power output stage to the actuators, an additional actuator was incorporated to provide the necessary torque including margins, and the power supply was increased to provide the required 80+ amps, instead of the previous 40 amp capabil
6、ity. Multiple failures during qualification testing, and the subsequent technical investigations, proved the lack of understanding between the ideal circuit operation and the impact of system implementation. Lesson(s) Learned: Adequate spares must be carefully considered, especially when undertaking
7、 significant modifications Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-to an existing design. When failures appear during the testing process, a re-evaluation of the spares level should be performed. Long replacement lead times can have a signifi
8、cant impact on project schedule. Recommendation(s): The determination of the adequate number of spare (sub)assemblies should be revisited as soon as failures appear. Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Sc
9、iencea71 Aeronautics ResearchAdditional Key Phrase(s): a71 Accident Investigationa71 Flight Equipmenta71 Hardwarea71 Safety & Mission Assurancea71 Test & VerificationAdditional Info: Approval Info: a71 Approval Date: 2006-04-17a71 Approval Name: dkruhma71 Approval Organization: HQProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
