Hi all, I just bought a PH 4 Pro with less than an hour on it and took it out yesterday for some training. Noticed at some point I could hear a high pitched kind of noise that was intermittent but consistent throughout the hour or more I practiced. In layman's terms it sounded like a dry bearing on a more traditional piece of equipment. I found a YouTube vid of someone with the same problem but no description of what the problem was. Just trying to get an idea before I have to take it to the shop. Anyone out there with a similar problem? I installed low noise props when I got it so the sound is easier to hear on mine than the one in the video. YouTube link below. Thanks.