What is the sound I'm hearing?

[Lewis - A2A]

Hello,

no one else is experiencing this no, so its something unique to your setup. Can you let us know what shape your aircraft is in in the maint hanger and that you completely a pre-flight inspection?

thanks,
Lewis

[kramerdc9]

Yes, that's correct. The sound of the virtual throttle before contact at low rpms. Try the keyboard and see if you experience the same thing. Just press the key from 1500rpm to 1000rpm and see if it happens. I guess it really doesn't matter what happens using a keyboard since where using joysticks/yokes. I just wanted to test and see if it would do the same thing.

[kramerdc9]

Hello,

no one else is experiencing this no, so its something unique to your setup. Can you let us know what shape your aircraft is in in the maint hanger and that you completely a pre-flight inspection?

thanks,
Lewis

Hi Lewis,

Thanks for your help. The shape of the plane in the hanger indicates excellent shape. I've done many pre-flights and find no indication of anything wrong. It could be something I'm doing or unique to my setup, but I can't think of what. If you could point me in some direction of where to start, it would be greatly appreciated. Thanks again.

[Oracle427]

Lewis, it definitely affects me as well, and there have been a small handful of posts over the past couple of months with a similar problem description and resolution.

[Lewis - A2A]

Ok guys, so this is just using the keyboard. Can you capture the noise for us in audio or video form? You can mail it to me? (PM me for mail address)

thanks,
Lewis

[Oracle427]

No, I haven't tested using the keyboard yet. I have the problem because of a noisy potentiometer in my mixture lever on my saitek quadrant.

I'm assuming we are both hearing the same sound.

I'll record and post tonight.

[Oracle427]

This is a quick fraps recording of the sound I hear. I only had 30 seconds with the free version of Fraps so I had to rush it.

Note that there is knocking before anything moves and that is because the prop lever on my quadrant causes those knocking sounds too even though there is no prop lever on the 172. The control is mapped to support complex aircraft.

https://www.dropbox.com/s/zcx6dr4t9xds6 ... A.mp4?dl=0

[kramerdc9]

Ok guys, so this is just using the keyboard. Can you capture the noise for us in audio or video form? You can mail it to me? (PM me for mail address)

thanks,
Lewis

Hi Lewis. To answer your question as regarding the keyboard. No, this happens with my joystick Saitek X 52. I only tested the keyboard to see if it did it on that too. I don't know if I can capture the sound myself. I would have to get fraps or something equivalent to it. I can however look on youtube and see if I can notice it and email you it with details. So let me see what I can do and I'll try to get in contact with you asap.

[Oracle427]

kramerdc9,

Did you see my above video? Are these the sounds you are hearing?

[kramerdc9]

Yes, that's the noise of the virtual levers. I made a short clip using free fraps that is compressed. I can't seem to upload it in a pm here. I know I can send via my email. I you'd like, I can do that.

[Lewis - A2A]

Okie dokie got the video via email. All sounds normal, as the engine revs up you get the airframe rattle and roll a bit more and as its cut the engine pops and rattles a little also.

thanks,
Lewis

[kramerdc9]

Okie dokie got the video via email. All sounds normal, as the engine revs up you get the airframe rattle and roll a bit more and as its cut the engine pops and rattles a little also.

thanks,
Lewis

Hi Lewis, glad you viewed the video. However, when you say normal your saying that the clunking noise is the airframe? Because the noise I'm hearing is like the sound when the power has been pulled all away to idle. The clunking noise sounds kind of like bad spark plugs, but my plane is in good shape. Besides, the clunky noise is when the power is being reduced, not increased. I could understand the airframe rattling revving up, but not down. If for some reason you can't identify what I'm hearing, could you please pass the video to Scott and see what his reaction is?Once again, I do appreciate your time and help.

Thanks,
Dirk

[Oracle427]

I haven't seen the video so I can't comment on that, but for what it is worth...

It is perfectly normal for an IO-360 engine to make a popping sound as it revs down when the throttle is pulled back. You can get a loud backfire if you pull it back abrubtly.

I haven't tested for this in the simulator to see if it is simulated.

The airframe will definitely quiver as throttle is added or taken away. You are running a 7 liter engine with a lot of torque up there on a very lightly built frame! A Lamborghini Gallardo is producing about the same amount of torque.