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Thread: Wood fixed pitch Propeller sound changes

  1. #1
    Basic Member
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    Default Wood fixed pitch Propeller sound changes

    Crazy question and just wondering if anyone else has ever experienced this. We just installed a wood fixed pitch propeller on our S6. We are running a Rotax 80Hp engine. At around 4800 RPM static the sound from the prop changes. It gets a deeper tone to it. Very noticeable. During a take off roll it does the same thing around maybe 5200 RPM and that tone remains until you start to climb out then is seems to go away. Don't seem to hear it in cruise. Normal or not normal?

  2. #2
    Premium Member (Donated) s19flyer's Avatar
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    Have you checked the tracking on the prop? If it's out a lot it can cause this.
    Glenn
    Avid Flyer, S6ES, S19, S20 In Progress
    http://www.mykitlog.com/s19flyer
    Remember, I am not immune to mistakes!
    What works for me may not work for you.

  3. #3
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    Thanks I will take a look at that

  4. #4
    Premium Member (Donated) scsirob's Avatar
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    It may well be normal. As your prop speed increases, the prop noise increases exponentially. On the ground the prop noise is very noticable, while in the air it's a lot less due to free space around the aircraft, and the noise dissipating as you move through the air.

    Here's a sample take-off from my S-6S. Different engine, but wooden prop and very similar effect. https://youtu.be/AZltnMpPADs?t=3m7s

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