Seamless Verification
Physical FOR: Wire $830When wire harnesses are installed into aircraft, they may be pulled through structure, against electrical equipment, and other wire harnesses. In these scenarios, wire/cable constructions with an extruded surface will experience less damage than those wire/cable constructions with a non-uniform (non-smooth) surface. The non-uniform surface is common for tape-wrapped insulation constructions.
The Seamless or Smooth Surface Verification test is a process control test used to ensure that smooth wrapped tape insulation has properly annealed without a visible outer edge or observable internal wrapping lines.
More information on the benefits of seamless wires/cables can be found here.
Procedure
- Perform visual examination of the specimen. Record any anomalies or defects.
- Place the specimen perpendicularly into the casting mount, and pour casting compound and allow it to harden.
- Using increasingly finer grit sandpaper, polish the cross sectional surface of the specimen until completion with 600 grit sandpaper.
- Under 200x magnification, investigate for signs of outer edges or visible spacing of insulation layers.
- Record and report results.
Covered specifications
- WC27500 Section 4.3.20
- AS4373 Method 110
- AS22759 Paragraph 5.3.6