REG NASA-LLIS-1182--1990 Lessons Learned - Atlantis Fuel Cell Mishap Investigation Board Report - April 4 1990.pdf
《REG NASA-LLIS-1182--1990 Lessons Learned - Atlantis Fuel Cell Mishap Investigation Board Report - April 4 1990.pdf》由会员分享,可在线阅读,更多相关《REG NASA-LLIS-1182--1990 Lessons Learned - Atlantis Fuel Cell Mishap Investigation Board Report - April 4 1990.pdf(9页珍藏版)》请在麦多课文档分享上搜索。
1、Lessons Learned Entry: 1182Lesson Info:a71 Lesson Number: 1182a71 Lesson Date: 1990-04-04a71 Submitting Organization: KSCa71 Submitted by: George W.S. Abbey/ Eric RaynorSubject: Atlantis Fuel Cell Mishap Investigation Board Report - April 4, 1990 Description of Driving Event: On April 4, 1990, at ap
2、proximately 9:05 a.m. EDT, one of the three fuel cells (#3) installed in the Orbiter Atlantis, OV-104, was damaged while an attempt was being made to vent the fuel cell prior to its removal and replacement. Atlantis returned to the Kennedy Space Center (KSC) on March 3, 1990, after successfully comp
3、leting the STS-36 mission. The vehicle was undergoing processing in the Orbiter Processing Facility (OPF) in preparation for the STS-38 mission in July of this year. Testing and processing was being accomplished by the Shuttle Processing Contractor (SPC) at KSC. The Fuel Cell Single Cell Voltage Tes
4、t was accomplished on March 30 and 31, and the analysis of the test results indicated there were two degraded internal cells. A decision to remove and replace the fuel cell was subsequently made on April 2 by the Orbiter Project Manager.The accident occurred while attempting to vent the fuel cell wi
5、th the Orbiter hydrogen (H 2) purge vent port capped. This allowed the H2 pressure to exceed the oxygen (02) pressure in the fuel cell, 2 side of the fuel cell. The Potassium Hydroxide (KOH) was found at the 02 purge port of the fuel cell indicating the ninety-six internal cells, the regulator, and
6、the accumulator would have to be replaced due to the corrosive qualities of KOH. No one was injured and damage was limited to fuel cell #3.Lesson(s) Learned: On Saturday, March 31, the mid-body mechanical supervisor and the lead mechanical technician both had the day off. Supervision was delegated t
7、o the lead electrical technician for that shift. He was not familiar with the work to be accomplished or with the capabilities and experience levels of the individuals assigned from the mechanical group. Two individuals were assigned to a task they had not previously performed or observed. The quali
8、ty inspector was a check and balance that might have caught the error had he been assigned based on his experience with the task or his knowledge of the system. Quality inspectors are not given inspection work based upon their knowledge or previous Provided by IHSNot for ResaleNo reproduction or net
9、working permitted without license from IHS-,-,-inspection assignments. They respond to a call-board that lists tasks calling for an inspector; consequently, an inspector appears in a somewhat indiscriminate fashion to perform the inspection task.On second shift, Saturday, March 31, three people unfa
10、miliar with the task came together on platform 4 west to perform and verify Operations and Maintenance Instruction (OMI) V1093 Post Operations Instruction #3.The lead mechanical technician from first shift stayed over to take the assigned technician to platform 4 west to review the task. He failed t
11、o mention that the purge vent port should not be capped after removal of the flex hose. There was no precautionary note in the OMI addressing the need to keep the purge vent port clear and open and no placard on the Orbiter. One of the significant shop practices stressed to all technicians working a
12、round the Orbiter is to cap disconnected lines or openings to avoid contamination. Personnel are therefore naturally conditioned to cap lines and openings.The fuel cell had to be vented to ambient pressure prior to its removal. The first attempt to vent the fuel cell by a fuel cell system engineer o
13、ccurred on Wednesday, April 4, at approximately 2 a.m. EDT. The fuel cell was not damaged at this point because the 02 reactant valve did not close. The fact that there was no H2 flow was observed but no Interim Problem Report (IPR) was initiated. A disconnected ground wire from the 02 reactant valv
14、e prevented the valve from closing and consequently protected the fuel cell from any damage.A walkdown was not accomplished by engineering. Had such a procedure been implemented, the damage might have been avoided as the fuel cell system engineer might have been alerted to the disconnected ground wi
15、re and the capped purge vent port.One thread that runs through the series of events leading up to the mishap is the lack of system training for technicians and quality inspectors. Technicians and quality inspectors are trained and certified in their basic skills, i.e, lockwiring, torquing, etc.; how
16、ever, they are given no Orbiter systems training. Another factor that contributed to this mishap is the lack of communication between engineering, technicians, and quality. All OMIs are reviewed and approved in detail by several engineering organizations. Some portions of these approved OMIs are the
17、n handed over to shop personnel (technicians) to be performed without requiring additional engineering involvement. This same situation exists with the quality inspector who must approve the technicians work. The personnel are highly motivated and want very much to do a good job. It is essential tha
18、t they be given the knowledge they need to do that job.The importance of keeping the purge vent port clear and open was not communicated by anyone in the process. The capping of the Orbiter H2 purge vent port during the performance of OMI V1093 Post Operations Instruction #3 was not an isolated inci
19、dent. On March 19, the same port was capped on the Orbiter Columbia, OV-102, during performance of the same OMI. In this case, an experienced Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-technician checking the work caught the error and had the ca
20、p removed. The supervisor was notified but no subsequent action was taken. Had this near-miss been properly communicated to all technicians, engineering, and quality, perhaps the mishap two weeks later could have been avoided. The significance of effective communications cannot be overemphasized in
21、the very complex world of Orbiter processing and test operations. Communications and identification of precautions in the OMI and a good working relationship between the technicians, the engineers, and quality personnel is essential to successful operations.The geography of KSC facilities does not l
22、end itself to ease of overview or development of team unity. The Launch Control Center (LCC) control rooms, from which systems engineers conduct tests, are a considerable distance from the OPF where technicians perform work on the vehicle. The remoteness of the two facilities impedes communications
23、between engineers and technicians. As the program plans new control rooms and equipment, these new rooms could be located in the OPF between the two bays. Many benefits would be derived from the control rooms being in such a location. Having the engineers in close proximity to technicians and the ve
24、hicle would improve the overall efficiency of orbiter processing as well as communications among all parties. A key factor in achieving a higher flight rate is reducing OPF flow time. This change could substantially enhance KSCs capability to achieve shorter processing flows. The ability of engineer
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- REGNASALLIS11821990LESSONSLEARNEDATLANTISFUELCELLMISHAPINVESTIGATIONBOARDREPORTAPRIL41990PDF
链接地址:http://www.mydoc123.com/p-1018821.html