Changed my mind about wire shielding after a weird find on a CRJ-200

I was always one of those guys who thought any old shielding was fine as long as it kept the wires bundled. Then last month I was looking at a bulging harness on a CRJ-200 in our hangar in Phoenix and found a service bulletin from 2019. Turns out a specific type of spiral wrap can trap moisture against the wire bundle, which leads to chafing and eventually shorts. Has anyone else run into a bulletin that totally changed how they do a basic task?

2 comments

2 Comments

beth_stone3d ago

Oh man, does that ring a bell? I had a similar wake-up call a couple years back on a King Air. I always used that cheap spiral wrap because it was quick and easy, and I figured hey, it's just keeping things tidy. Then I found a bulletin that showed how that same wrap can actually create little friction points against the jacket over time, especially in a hot, vibrating engine bay. Totally changed how I prep any harness near heat or moisture now, your mileage may definitely vary but that bulletin saved me from a real headache down the road.

wadeowens3d ago

I gotta push back on that "totally changed how I prep" stuff. Spiral wrap has been working fine for decades and this bulletin sounds like a classic case of overthinking a non-issue. You say it creates friction points in a hot vibrating engine bay but I've seen the same wrap hold up perfect in Mooney and Piper engine bays that shake way worse than any King Air. Moisture trapping? Maybe if you pack it tight and leave it in a swamp but Phoenix is dry as a bone. I think people chase these bulletins too quick without remembering that sometimes simple solutions with a solid track record are still valid.