Preflight tip #537 – Ping your Prop

Preflight checks are a bit of an art form. There are commonalities to how we all do the “walkaround”, but I propose that no two pilots perform them exactly the same. We all individualize them to a degree.

I know my own method has mutated over the years, largely as a function of what I’ve learned from real live squawks. Cooling baffle cracks, dead bulbs, and low tires are always common. Loose hinges aren’t so common, but they do seem to subtly show up here and there, as do leaky brakes and fuel weepage. I don’t know if too many pilots look around a fuel sump and wing root for signs of hidden leaks, but I’ve certainly come to do it.

One place I’m particularly paranoid, yet have never yet found a real problem, is around a propeller. This one seemingly simple aluminum forging can really ruin your day should something bad happen. We all know that any nicks severe enough to catch a shop towel should be dressed out, but besides that, there’s not much we can do to catch an impending problem.

So, I caught this little “never-thought-of-that” gem in an article discussing seaplane preflights from the May/June issue of “Water Flying” (the bi-monthly member publication of the Seaplane Pilot’s Association). Besides the fingernail test that I’ve oft heard described, the author also suggests a “ping test”. That is: tap the propeller blade lightly along it’s length with a coin, and listen for anything unusual regarding the character of the resonant “ring”. Anything wrong should cause a significant change in the sound.

I just might have to try this…


3 Responses to “Preflight tip #537 – Ping your Prop”

  1. 1 Frank June 28, 2010 at 9:55 am

    Re: “pinging” the prop…been doing it for years. Taught to me by an old pelican of a CFI. Haven’t found any problems yet, but it doesn’t cost a lot to do the check.


    • 2 airphoria June 30, 2010 at 8:21 pm

      It made a ton of sense once I read it, but I never would have thought of it myself. Makes me wonder just how much of this kind of simple knowledge is simply lost to the sands of time.

      Tried it on two school airplanes I’ve taught in this week. They seem just fine 😉

  2. 3 Michelle June 30, 2010 at 6:05 pm

    I have done this with pottery. It’s a good way to hear if you have a cracked pot 🙂 The sound of a pottery bowl or vase “sings” a tone of soundness when you flick it with your fingers. A cracked pots sounds off as a flat “Bonk”….same line of reasoning I believe :).

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