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NASA-LLIS-1217
Lessons Learned – Sharp edge hazard from break-off assemblies
Year: 1998
Abstract: Description of Driving Event:
"Hi-Lite" (similar to Hi-Lok) pin and collar fasteners are widely used on ISS Power Module structural assemblies. As part of an internal sharp-object-damage (SOD) identification and mitigation activity, it has been noted that small burrs are present on most installed collars. When accessible to an astronaut's EMU external surfaces, these burrs pose a sharp object hazard with risk of damage to the EMU outer fabric.
Root cause: As part of "Hi-Lite" fastener installation, a wrench is applied to a drive nut integral with the fastener collar. At a given torque, the drive nut shears from the collar body; the drive nut is then scrapped. This shearing action typically leaves burrs on the collar surface.
"Hi-Lite" (similar to Hi-Lok) pin and collar fasteners are widely used on ISS Power Module structural assemblies. As part of an internal sharp-object-damage (SOD) identification and mitigation activity, it has been noted that small burrs are present on most installed collars. When accessible to an astronaut's EMU external surfaces, these burrs pose a sharp object hazard with risk of damage to the EMU outer fabric.
Root cause: As part of "Hi-Lite" fastener installation, a wrench is applied to a drive nut integral with the fastener collar. At a given torque, the drive nut shears from the collar body; the drive nut is then scrapped. This shearing action typically leaves burrs on the collar surface.
Subject: Extra-Vehicular Activity
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| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T16:37:54Z | |
| date available | 2017-09-04T16:37:54Z | |
| date copyright | 36089 | |
| date issued | 1998 | |
| identifier other | VGVEQCAAAAAAAAAA.pdf | |
| identifier uri | https://yse.yabesh.ir/std/handle/yse/101451 | |
| description abstract | Description of Driving Event: "Hi-Lite" (similar to Hi-Lok) pin and collar fasteners are widely used on ISS Power Module structural assemblies. As part of an internal sharp-object-damage (SOD) identification and mitigation activity, it has been noted that small burrs are present on most installed collars. When accessible to an astronaut's EMU external surfaces, these burrs pose a sharp object hazard with risk of damage to the EMU outer fabric. Root cause: As part of "Hi-Lite" fastener installation, a wrench is applied to a drive nut integral with the fastener collar. At a given torque, the drive nut shears from the collar body; the drive nut is then scrapped. This shearing action typically leaves burrs on the collar surface. | |
| language | English | |
| title | NASA-LLIS-1217 | num |
| title | Lessons Learned – Sharp edge hazard from break-off assemblies | en |
| type | standard | |
| page | 2 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;1998 | |
| contenttype | fulltext | |
| subject keywords | Extra-Vehicular Activity | |
| subject keywords | Flight Equipment | |
| subject keywords | Ground Equipment | |
| subject keywords | Hardware | |
| subject keywords | Parts Materials & Processes | |
| subject keywords | Risk Management/Assessment | |
| subject keywords | Safety & Mission Assurance | |
| subject keywords | Test & Verification |