RV-8 In Flight Fuselage Noises

[wera710]

Pretty much. Good video! For the new to TD guys: Even if you get a little float in ground effect it still works. Looks like he pulled power right at touch down and transitioned right onto all three wheels. For fix props, you can pull it sooner, relax pressure on the stick a little and it works the same, but with slightly slower roll out. Nice thing is, even if you do not flair and touch down at the same time, you can still hold it off the ground (the "not to let it land trick") and it will just transition into that attitude, coast along a few feet and then settle onto all three wheels.

[flyenforfun]

I have a noise in my 8 that sounds like propeller tip noise. its louder at high angles of attack and it will go away if I slip the airplane to the side. One day I closed the rear air vent and it went away and of course it comes back when I open it. I don't know if its coming from the prop but its definitely coming through the rear air vent.

[Mike H]

Most likely structural vibration. Probably coming from the forward belly skins and or lower IB wing skins. Some RV-8 owners have reported belly skin cracks most likely due to vibration. Can be easily fixed using a structural damping material. Lots of certified aircraft use damping material/composites to prevent skin stress/cracking and reduce noise. Have fixed similar issues in several PA-28s.

http://www.aircraftspruce.com/catalo...lickkey=113451

http://www.earsc.com/HOME/products/D...ex.asp?SID=150

http://www.earsc.com/HOME/products/D...ex.asp?SID=353

[bruceg]

Originally Posted by flyenforfun

I have a noise in my 8 that sounds like propeller tip noise. its louder at high angles of attack and it will go away if I slip the airplane to the side. One day I closed the rear air vent and it went away and of course it comes back when I open it. I don't know if its coming from the prop but its definitely coming through the rear air vent.

Same noise in my 8 when the vent was open. When I had the floor out, I noticed that the scat tube that supplies air to the vent was not secured well enough to keep the tube from vibrating against the bottom skin. There were significant wear marks in the skin. Securing the tube stopped the noise.

[Neal@F14]

My friend's RV-8 that I helped build would make a vibrating racket from the aft end of the plane that sounded like the tail was trying to come off in flight. Using rudder to yaw left or right would change the pitch and with a certain amount of side-slip held in, the vibrating noise would almost but not quite go away.

It turned out to be the rear of the canopy skirt rubbing up against the top of the turtle deck behind the rear seat... we discovered that as the paint started to wear thru where the rubbing was occurring.

Putting some foam weather stripping in there and it silenced the noise completely.

[David-aviator]

The noise I hear on every flight when slowing through 90 knots or so is a distinct "whomp" oil can sound. It is not vibration.

The vibration noise heard earlier was the back seat rattling against the fuselage support structure.

[Mike H]

Originally Posted by David-aviator

The noise I hear on every flight when slowing through 90 knots or so is a distinct "whomp" oil can sound. It is not vibration.

The vibration noise heard earlier was the back seat rattling against the fuselage support structure.

David, if you can locate the section of skin causing the loud oil canning noise you can fix it with some of the adhesive backed structural damping material.

[flyenforfun]

I suspect it is the scat tube vibrating against something but I haven't been able to find it yet. I am doing the annual right now and I was thinking of wrapping the tube with some kind of insulation.

Originally Posted by bruceg

Same noise in my 8 when the vent was open. When I had the floor out, I noticed that the scat tube that supplies air to the vent was not secured well enough to keep the tube from vibrating against the bottom skin. There were significant wear marks in the skin. Securing the tube stopped the noise.