1、Public Lessons Learned Entry: 2716 Lesson Info: Lesson Number: 2716 Lesson Date: 2010-04-8 Submitting Organization: KSC Submitted by: Annette Pitt Subject: Thermal Control System (TCS) Blanket Interference with Xo378 Bulkhead Vent Ports Video Lesson Abstract: TCS blankets by nature have a close and
2、critical dimensional relationship to the surrounding hardware they are insulating. Blankets were installed incorrectly over the Purge Vent Drain (PVD) lines in the Forward Reaction Control System (FRCS). Incorrect installation allowed the blankets to billow toward the Xo 378 bulkhead vents, restrict
3、ing venting of the FRCS cavity. Description of Driving Event: During STS-121 ascent, the Xo 378 bulkhead delta-pressure transducer showed higher than normal pressure differential across the bulkhead. Following the STS-121, ground borescope inspections on FRC3 showed that TCS blankets in the FRCS mod
4、ule were very close to the vents, and were not installed under the Purge Vent Drain (PVD) lines. Design intent is to install the V070-361995-024 Left Hand (LH) and V070-361995-025 Right Hand (RH) Multilayer Insulated blankets (MLI) under PVD drain lines in the FRCS. The blankets contain existing cut
5、outs and cutlines, allowing installation under these lines. When properly installed, the blankets are restrained by the PVD drain lines and cannot billow into the Xo 378 vent areas. Using templates to simulate a Xo378 vent port, TCS Engineering determined that blockage of the vent ports can occur wh
6、en blankets are installed on top of the drain lines. Improper installation of the TCS blankets was determined to be the cause of the vent anomaly. Lesson(s) Learned: The interface between TCS blankets and their associated hardware needs to be clearly and unambiguously documented on the installation
7、drawings so that blankets perform as designed without unintended interferences or blockages particularly related to cutouts and openings. System operators need to understand how all the pieces fit together so that each team member appreciates how their contribution affects the integrated system. FRC
8、3 Blanket as installed at HMF prior to incident. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-LH FRC3 Blanket in relationship to FRCS Cavity Bulkhead PVD vent post STS-121 Provided by IHSNot for ResaleNo reproduction or networking permitted withou
9、t license from IHS-,-,-RH FRC3 Blanket in relationship to FRCS Cavity Bulkhead PVD vent post STS-121 Click the icon to view a brief video of this lesson Recommendation(s): Maintain an integrated overall systems perspective so that build up of individual parts work as designed particularly in view of
10、 modifications and rework. Evidence of Recurrence Control Effectiveness: Controls have been added to the V63-50049 job card that removes and installs blankets on to the FRC to prevent recurrence. The V070-361900 installation has been revised to reflect position of the blanket for this area. Document
11、s Related to Lesson: Click here to download corrective action document 21RF08 Click here to download problem resolution document PR FRC3-A0050 Mission Directorate(s): Space Operations Exploration Systems Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-
12、,-Additional Key Phrase(s): 1.Launch Systems 1.Logistics and maintenance 1.Launch support systems 1.Ground processing and manifesting 1.Human factors planning 1.Engineering design and project processes and standards 1.Configuration control and data management 1.Early requirements and standards defin
13、ition 1.Launch Vehicle 1.Flight Equipment 1.Human factors impact on mission design 1.Long term sustainability and maintenance planning 1.Accident Investigation 1.Impact of human factors on systems requirements and designs 1.Configuration Management Additional Info: Project: Space Shuttle Program Approval Info: Approval Date: 2010-07-07 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
