Serious question, why do so many shops skip the full ground loop check on new installs?

I've seen three separate aircraft in the last two months with intermittent static on the comms that traced back to a bad ground strap on a fresh GPS install. The techs just verified the unit powered on and called it good. A proper loop check with a multimeter set to continuity takes maybe five extra minutes per ground point. It matters because that static can mask a real emergency call. Has anyone else's shop started making this a mandatory sign-off step?

3 comments

3 Comments

parker18318d ago

That static masking an emergency call is why I ALWAYS do the loop check now.

tara_patel18d ago

Actually, that static is usually from a bad ground, not a loop issue. The loop check won't always catch a ground fault, @parker183. You need to test the resistance between the common terminal and a known good ground, should be under 25 ohms. A lot of guys miss that step.

ericj4518d ago

Right, and a bad ground can get worse over time too. So even if it passed when it was new, corrosion or a loose lug can push that resistance way up later. Makes you wonder how many "weird noise" service calls are just a ground that's slowly gone bad.