Loading…

A rainy night in Seattle taught me to always check the grounds first | Avionics Technicians - Librear

A rainy night in Seattle taught me to always check the grounds first

I was working a night shift at SeaTac on a CRJ-900, chasing a weird autopilot fault that only showed up in heavy rain. The logs were pointing to the flight control computer, so I was ready to pull and replace it, which is a huge job. My lead, an old guy named Carl, walked over, looked at the work order, and just said 'Go check pin 14 on the main avionics ground block in the wheel well. Trust me.' I was soaked and annoyed, but I did it. Sure enough, the terminal was loose and covered in light corrosion. A five-minute clean and tighten fixed what I was about to spend four hours on. He told me later he saw the same thing on a dozen planes at that same airport because of how the rain gets driven up into the bay. Now I start EVERY fault tree from the ground up, literally. Anyone else have a specific airport or plane type that seems to have its own special gremlins?

3 comments

3 Comments

patricia_rodriguez7mo ago

Starting from the ground is smart, but I've seen way more issues come from bad connectors than bad grounds. Gotta check the whole chain.

karenlee6mo ago

Last year I spent three hours chasing a ground fault that turned out to be a single pin in a weatherpack connector that had backed out just a millimeter. The whole harness looked perfect until you unplugged it. Now I keep a tube of dielectric grease in my toolbox and smear a tiny bit on every connector I reassemble, it helps keep moisture out and the pins seated. It's a cheap fix that saves so much headache later on.

hugom267mo ago

True, connectors are a huge weak spot. What's the most common failure you see, corrosion or just loose fittings? I've had more than a few problems that looked like a ground but were actually a connector halfway down the line that looked fine until you wiggled it. Makes troubleshooting a real pain.