RV14A Canopy Noise

[barryrv10]

I am helping to test fly a 14A with an IO-390 and Hartzel 2 blade BA prop. We are getting a high pitch noise at 120kt that gets worse the faster we go. It has been present with wheel pants and fairings on or off. Our ANR headsets do not filter the noise; it sounds like the noise you made when as a kid you blew across a blade of grass. I have never flown with this big of a canopy before and was checking if anyone else had this effect. Thanks Much

[Allan Stern]

No such noise in my canopy. Or have not heard it yet.

[mturnerb]

Check different settings for vents.

[Bavafa]

No such noise on mine either.

[gsxphil]

Ive had a similar situation in my 9A tip-up. I found it was coming from the front of the canopy section, the gap between the forward fuselage skin and canopy. Did you install the seal there? When this happened on mine I had not yet installed the seal on the forward section.

Phil

[Mark Browning]

I had a similar issue with my RV-7 I changed the canopy seal type and it stopped
If you believe that its coming from the canopy look for any possible areas that look like they could cause the problem
Front and rear of the canopy would be the most common area

Ask someone to tape the rear shut gap fly the Aircraft and listen.
If the noise disappears, land and have the same person waiting to remove the tape. Its a bit of trial and error but will help you to locate or dismiss the area

[swisseagle]

I have this on my RV-7A. At the beginning it is ok, after about an hour it starts to annoying you.

My buddy has the same, he tested it like this:
He sit into the plane, someone was from outside placing a small tape over the gap between tip-up and rear-window.
Then test flying and the noise was gone.
The final solution was a targa-stripe at the tipup/rear window section.

It is still on my to do list ...

[barryrv10]

Thanks for the info guys; the front seal was removed because there was interference with the seal and the canopy lip. We will install a new seal and see what that does.

[bjdecker]

Originally Posted by swisseagle

I have this on my RV-7A. At the beginning it is ok, after about an hour it starts to annoying you.

My buddy has the same, he tested it like this:
He sit into the plane, someone was from outside placing a small tape over the gap between tip-up and rear-window.
Then test flying and the noise was gone.
The final solution was a targa-stripe at the tipup/rear window section.

It is still on my to do list ...

Both of my RV-7 tip-ups had the whistle; root caused to be the gap between the canopy halves at the top of the roll bar.

I put a section of rubber seal (https://www.mcmaster.com/1067a3-1067A43) about 3/4" or so forward of the aft edge of the front canopy; positioned so the seal would just touch the front edge of the roll bar but not interfere with the closing of the canopy.

You can also run a piece of https://www.mcmaster.com/1120a112 along the inside flange of the canopy bow so the bulb forms a seal against the roll bar. You will need to make a notch for the center latch.

Cheers!

B

[Carl Froehlich]

Yep, same exact problem on a first flight RV-14A I know of.

Root issue, he left off the canopy seal gasket as he figured to put it on after paint. Gasket on, the high pitched noise went away.

Carl