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The day I stopped ignoring pin test data on old wiring
I spent 3 years doing avionics work and always just did continuity checks on old harnesses. Thought it was good enough since the wires showed no breaks. Last Tuesday a buddy brought out a DIT-MCO tester and ran me through a full pin-to-pin isolation test on a 20 year old 737 harness. Found 3 latent shorts that would have killed the whole IRU feed. I had been telling people all that testing was overkill. Now I see why the senior guys laugh at my old methods. Any of you guys use a proper wire analyzer on every pullout or just when something acts weird?
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mason.brian1mo ago
Are you sure that DIT-MCO tester didn't just give you a false positive? In my experience, those things can be super sensitive and pick up stuff that doesn't matter in the real world. I've seen guys chase 'shorts' that were just surface moisture or flux residue that wouldn't ever cause a problem under normal flying conditions. A good visual check and a basic continuity test have worked for decades, and I'd rather trust my eyes and a simple multimeter than some overengineered box that costs more than my truck. You might be chasing ghosts and wasting a lot of time for no real safety gain, your mileage may vary.
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shanem371mo ago
Remember back in the day when a guy on my crew swore his DIT-MCO was showing a short in a connector. @mason.brian, we spent half a shift tearing it apart, only to find a tiny piece of leaf from a tree had blown into the panel during testing. I'm with you, sometimes the old school way is the best way.
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