That old timer told me to check the bonding straps first and I should have listened

I spent three hours last Tuesday tracing a ghost issue on a King Air's nav display. Swapped out the antenna, checked the coax, even pulled the display unit itself. Finally my buddy Dave who's been doing avionics since the 80s walks by and says 'did you check the bonding strap on the flap?' Sure enough, loose screw on the bonding strap near the left flap actuator was causing noise. Cost me a whole afternoon because I was too stubborn to start simple. Anyone else ever waste time ignoring the basics from the old guys?

3 comments

3 Comments

jessica92110d ago

Did your buddy ever explain why those flap bonding straps are the first thing to check? A friend of mine worked on a Cessna 172 for two days trying to fix a radio that would cut out during turns. He'd replaced the whole audio panel before someone older pulled him aside and pointed out the ground strap on the elevator trim tab was barely hanging on. The old guys must have a list of common trouble spots burned into their brains from all the years of fixing the same problems.

xena58210d ago

There was a good article in Avionics News a few months back that went over how grounding issues cause like 40% of intermittent electrical problems in older airframes. @jessica921 nailed it with that Cessna story because those ground straps on moving surfaces get overlooked constantly since people focus on the black boxes first. I read somewhere that the old mechanics have that list memorized from just seeing the same failure modes repeat themselves for decades. The flap bonding strap is such a classic because it's a moving part that takes a beating from vibration and weather. It's wild how a simple mechanical connection can cause total chaos in a digital system if it gets loose.

singh.harper10d ago

Exactly, the old school guys just know those moving parts create headaches that digital diagnostics miss.