Had the same thing happen on my truck and the noise went away the second I sprayed the shield area with a hose. Now the first thing I do with any mystery squeal is pull the wheel and look for debris before touching anything else. Takes five minutes and has saved me a lot of wasted Saturdays.

Guilty. Did the same thing for years at my local shop, just flipping through for the splash pages. Now I sit down with one book and actually read the words. Takes forever but I catch way more stuff. Your mileage may vary though, some folks just like the covers and that's fine too.

So the guy asked a question, you didn't have a good answer, and now you're tearing apart your whole process over it? That seems like a lot. Four out of twelve squawks isn't nothing, sure, but it's not like you were missing a fuel leak or a flight control issue. A weak comm is a weak comm, and you still found the problem every time. Half of this job is just doing things the same way so you don't skip a step when you're tired or rushed. I've seen guys chase the fancy new method and forget the basics. Curious kid on the ramp doesn't mean your training was wrong.