Harmonic aerodynamic Noise at medium to high speeds

[procharger]

That is wind noise through a crack or opening like everyone else said I had that to.

[AGLyme]

Yup tape void for sure

[oceanplexian]

I had this issue a few times in my CTSW and took all the tape off, then it came back. Turned out I had whistling coming from the front of the cowling where the air intake hole is. When you put the bottom and top cowlings together you have to be careful to make sure that round fiberglass bit lines up right with the cowling, otherwise it turns into a reed that can make a loud sound like a stall horn. 

BTW one tip I have for troubleshooting this is get an air compressor and (carefully) blow it around different areas, wing tape, etc. It will help you find what is vibrating in the wind.

[DJ Todd B]

Good Stuff.  I will investigate.  Thanks.

[DJ Todd B]

I still can't find the source of the noise however if I cover the left wing fuel sight Gage hole it does muffle the sound. All the tapes look good.  I was wondering if I removed both wing tapes and did a test flight with them off, should it be the tape, would the sound go away? In other words, with the tape removed from both wings, would that introduce any other sounds into my troubleshooting madness?

[DJ Todd B]

I still can't find the source of the noise however if I cover the left wing fuel sight Gage hole it does muffle the sound. All the tapes look good.  I was wondering if I removed both wing tapes and did a test flight with them off, should it be the tape, would the sound go away? In other words, with the tape removed from both wings, would that introduce any other sounds into my troubleshooting madness?

[Tom Baker]

I always flew my airplane without wing tape. You will be fine if you remove it.

[207WF]

I duct taped some cutouts from clear plastic sheets (old overhead projector slides) over my fuel sight gauge holes.  You can still see but it cuts the wind and noise down, which my wife appreciates.

WF

[Tip]

I fly without tape in the summer.

[DJ Todd B]

Problem SOLVED!   It WAS the tape.

I flew it last week and placed my hand over the Fuel Sight Gage hole and the noise was muted, so I removed the tape yesterday. 

Although the tape around the wing appeared to be good, I removed it anyways and the noise went away.  Thanks to everyone for chiming in on this. 

[Runtoeat]

I have had this noise show up after Fall when the temps drop and when there is old tape on my CT.  The tape becomes stiffer when cold.  If there's no visable rips or tears, then the tape may have lost it's adhesion to the wing. This was my problem.  This condition doesn't show but it allows the tape to lift off the wing and vibrate.  First thing to do if one has this "stall horn" hi pitched noise is just remove the tape and see if noise goes away.  If so, clean the surface and apply new tape as Roger describes.  Should fix the problem.  The noise is hi energy and easily comes thru Bose A20's

[Roger Lee]

The KEY to applying Bolus tape is to lay it down and DO NOT stretch it. Once stretched the wings do flex a bit at the gap which will eventually split the tape. Always clean the area with a mild solvent (like Goof-Off) to remove any left over adhesive before applying your tape. Apply a double layer of tape over the leading edge that takes all the wind pressure. Go back about 10" on top then come back around the front about 8" over the first layer. My tape always last until the next wing pull. 

If you stretch the tape it can and does split plus the leading edge tape gets pulled into the front will gap like a girl with a thong.