ASG-29 Coke Bottle Whistle

[RickH]

I hope some of you ASG-29 drivers have either experienced or heard of this issue I'm having with my 2012 ASG-29. The ship has about 200 hours on it. At about 100-110 knots I have a very loud and annoying sound that comes from the rear of the ship. It sounds just like someone blowing over a coke bottle to create a tone. I can get rid of the sound by applying a little rudder although the yaw string is running true while the sound is being generated. Rex Williams said he thought it was the tail dump opening. I've put duct tape over the tail dump valve and still have this annoying tone accelerating through 100-110 knots. John Murray thought that it was the gap seal tape on the rudder. I would have thought that would have produced more of a buzz sound but this is probably my next step. Hopefully someone can enlighten me as to a possible cause!

[[email protected]]

Let me know how you solve it. My LS-8 has the exact same noise at the same speed. Slight rudder pressure makes it go away. Rudder gap seals are tight.

[3j]

At 14:37 12 June 2016, RickH wrote:
>
>I hope some of you ASG-29 drivers have either experienced or
heard o
>this issue I'm having with my 2012 ASG-29. The ship has about
200 hour
>on it. At about 100-110 knots I have a very loud and annoying
soun
>that comes from the rear of the ship. It sounds just like someon
>blowing over a coke bottle to create a tone. I can get rid of the
soun
>by applying a little rudder although the yaw string is running tru
>while the sound is being generated. Rex Williams said he thought it
wa
>the tail dump opening. I've put duct tape over the tail dump valve
an
>still have this annoying tone accelerating through 100-110 knots.
Joh
>Murray thought that it was the gap seal tape on the rudder. I woul
>have thought that would have produced more of a buzz sound but
this i
>probably my next step. Hopefully someone can enlighten me as to
>possible cause
>
>
>
>
>--
>RickH
We had a similar issue with an LS4a. It turned out to be the root
wing seal tape on the lower surface. If the tape was not sealed
tightly to the lower surface, we would get the tone. The noise
sounded like it was coming from the aft end of the ship, but pressing
the tape tight to the lower surface of the wing would stop the
problem.

Jim

[[email protected]]

On Sunday, June 12, 2016 at 2:43:14 PM UTC-4, RickH wrote:
> I hope some of you ASG-29 drivers have either experienced or heard of
> this issue I'm having with my 2012 ASG-29. The ship has about 200 hours
> on it. At about 100-110 knots I have a very loud and annoying sound
> that comes from the rear of the ship. It sounds just like someone
> blowing over a coke bottle to create a tone. I can get rid of the sound
> by applying a little rudder although the yaw string is running true
> while the sound is being generated. Rex Williams said he thought it was
> the tail dump opening. I've put duct tape over the tail dump valve and
> still have this annoying tone accelerating through 100-110 knots. John
> Murray thought that it was the gap seal tape on the rudder. I would
> have thought that would have produced more of a buzz sound but this is
> probably my next step. Hopefully someone can enlighten me as to a
> possible cause!
>
>
>
>
> --
> RickH

Guessing it is turbulence over the rudder cable outlet which is not followed by a trailing faring. Fashion a faring out of DOW blue styrofoam square edge insulation (Lowes). First put down a strip of duck tape and then glue the shaped foam trailing faring to the duct tape. Do for both sides and flight test. If this eliminates the whistle then proceed to fabricate and permanently install FG shell faring.

[Gav Goudie[_2_]]

RickH,

How much equipment do you stow behind your head?

On my LS4 if there was too much equipment (sweatshirt, jacket etc) on the
cargo shelf it caused a 'choke' and the fuselage exhaust at the base of the
fin
would start to howl.

Trial an error sorted it out, but also worth making sure the internal
rudder
seal (if fitted) is fully adhered to the fin and making contact with the
rudder.

GG

At 14:37 12 June 2016, RickH wrote:
>
>I hope some of you ASG-29 drivers have either experienced or heard o
>this issue I'm having with my 2012 ASG-29. The ship has about 200 hour
>on it. At about 100-110 knots I have a very loud and annoying soun
>that comes from the rear of the ship. It sounds just like someon
>blowing over a coke bottle to create a tone. I can get rid of the soun
>by applying a little rudder although the yaw string is running tru
>while the sound is being generated. Rex Williams said he thought it wa
>the tail dump opening. I've put duct tape over the tail dump valve an
>still have this annoying tone accelerating through 100-110 knots. Joh
>Murray thought that it was the gap seal tape on the rudder. I woul
>have thought that would have produced more of a buzz sound but this i
>probably my next step. Hopefully someone can enlighten me as to
>possible cause
>
>
>
>
>--
>RickH
>

[Dave Springford]

Hi Rick,

I have the same 100 kt whistle on my 29. Just today replaced the upper mylar on the elevator in an attempt to remove the noise. I'll see if it goes away and report back. I also have new mylar for the lower surface and that is the next test if replacing the upper doesn't solve it. Let me know if you replace rudder seals and if that solves the problem on yours.

Dave Springford

[[email protected]]

The high speed noise is very common in the ASG29. The ASW 27 will also make the noise but needs to be at high altitude and high speed (like 17k at 105+knots.)

So sadly, I don't know of anyone who has cured this yet but maybe broadening the question to include ASW 27 pilots who fly regularly at high altitude will yield an answer.

In my own plane I've tried to seal air from getting into or out of the vertical fin via around the elevator and rudder joints. Not cured yet but I'll be at the Utah nationals next week so I'll be able to test out a couple of ideas.

[Craig Reinholt]

On Sunday, June 12, 2016 at 11:43:14 AM UTC-7, RickH wrote:
> I hope some of you ASG-29 drivers have either experienced or heard of
> this issue I'm having with my 2012 ASG-29. The ship has about 200 hours
> on it. At about 100-110 knots I have a very loud and annoying sound
> that comes from the rear of the ship. It sounds just like someone
> blowing over a coke bottle to create a tone. I can get rid of the sound
> by applying a little rudder although the yaw string is running true
> while the sound is being generated. Rex Williams said he thought it was
> the tail dump opening. I've put duct tape over the tail dump valve and
> still have this annoying tone accelerating through 100-110 knots. John
> Murray thought that it was the gap seal tape on the rudder. I would
> have thought that would have produced more of a buzz sound but this is
> probably my next step. Hopefully someone can enlighten me as to a
> possible cause!
>
>
>
>
> --
> RickH

As John Murry said.
My Discus 2b had the same issue after the rudder seals blew out in an overnight wind storm. I put them back in, but it still buzzed.
Craig

[[email protected]]

On Sunday, June 12, 2016 at 2:43:14 PM UTC-4, RickH wrote:
> I hope some of you ASG-29 drivers have either experienced or heard of
> this issue I'm having with my 2012 ASG-29. The ship has about 200 hours
> on it. At about 100-110 knots I have a very loud and annoying sound
> that comes from the rear of the ship. It sounds just like someone
> blowing over a coke bottle to create a tone. I can get rid of the sound
> by applying a little rudder although the yaw string is running true
> while the sound is being generated. Rex Williams said he thought it was
> the tail dump opening. I've put duct tape over the tail dump valve and
> still have this annoying tone accelerating through 100-110 knots. John
> Murray thought that it was the gap seal tape on the rudder. I would
> have thought that would have produced more of a buzz sound but this is
> probably my next step. Hopefully someone can enlighten me as to a
> possible cause!
>
>
>
>
> --
> RickH

Some things I have done with some success.
Install a bulkhead in the fin cove with a wiping seal against the leading edge of the rudder to stop flow up the fin cove area.
Seal the elevator push rod exit.
Add wipe seals to the sides of the elevator drive
Install ES vent so cockpit air exits forward instead of at the tail.
FWIW
UH

[Papa3[_2_]]

On a club LS4 as well as an LS4 I used to own, we had the same problem. Sounds like a bassoon player sitting in the area of the empennage. Turned out that sealing the top of the vertical stab with foam around the elevator pushrod solved the problem. My 29 hasn't yet displayed this musical tendency, but I have a Nixon/Murray exhaust vent which provides an optimized path for high pressure cockpit air to escape...

P3

[JS]

I've noticed only a quiet ~50Hz oscillation in flap position 3 at the higher end of the WK3 speed range.
Jim

[Tom Kelley #711]

On Sunday, June 12, 2016 at 12:43:14 PM UTC-6, RickH wrote:
> I hope some of you ASG-29 drivers have either experienced or heard of
> this issue I'm having with my 2012 ASG-29. The ship has about 200 hours
> on it. At about 100-110 knots I have a very loud and annoying sound
> that comes from the rear of the ship. It sounds just like someone
> blowing over a coke bottle to create a tone. I can get rid of the sound
> by applying a little rudder although the yaw string is running true
> while the sound is being generated. Rex Williams said he thought it was
> the tail dump opening. I've put duct tape over the tail dump valve and
> still have this annoying tone accelerating through 100-110 knots. John
> Murray thought that it was the gap seal tape on the rudder. I would
> have thought that would have produced more of a buzz sound but this is
> probably my next step. Hopefully someone can enlighten me as to a
> possible cause!
>
>
>
>
> --
> RickH

When my 29 was new in 2006, I had maybe the same noise around 95-100 kts. When I got home from the Nationals, I removed the rudder and really bent the mylar over. Used a small wood block and even creased it at almost a 90 degree angle. Reinstalled the rudder and the noise went away.
Then several years ago, installed new mylar. Didn't crease it over. Flew it and the noise came back. Came home, removed the rudder and bent it over using again a small block of wood to crease it and the nose went away. Several other folks with the same noise simply trimmed the mylar down from the top by an inch or so. The bottom they trimmed up. Their noise went away.

Best. Tom #711.

[Tom Claffey[_2_]]

I had this last season and fixed by adding V seals to the fin each side of
the
rudder.


At 14:37 12 June 2016, RickH wrote:
>
>I hope some of you ASG-29 drivers have either experienced or heard o
>this issue I'm having with my 2012 ASG-29. The ship has about 200 hour
>on it. At about 100-110 knots I have a very loud and annoying soun
>that comes from the rear of the ship. It sounds just like someon
>blowing over a coke bottle to create a tone. I can get rid of the soun
>by applying a little rudder although the yaw string is running tru
>while the sound is being generated. Rex Williams said he thought it wa
>the tail dump opening. I've put duct tape over the tail dump valve an
>still have this annoying tone accelerating through 100-110 knots. Joh
>Murray thought that it was the gap seal tape on the rudder. I woul
>have thought that would have produced more of a buzz sound but this i
>probably my next step. Hopefully someone can enlighten me as to
>possible cause
>
>
>
>
>--
>RickH
>

[RickH]

On Sunday, June 12, 2016 at 12:43:14 PM UTC-6, RickH wrote:
I hope some of you ASG-29 drivers have either experienced or heard of
this issue I'm having with my 2012 ASG-29. The ship has about 200 hours
on it. At about 100-110 knots I have a very loud and annoying sound
that comes from the rear of the ship. It sounds just like someone
blowing over a coke bottle to create a tone. I can get rid of the sound
by applying a little rudder although the yaw string is running true
while the sound is being generated. Rex Williams said he thought it was
the tail dump opening. I've put duct tape over the tail dump valve and
still have this annoying tone accelerating through 100-110 knots. John
Murray thought that it was the gap seal tape on the rudder. I would
have thought that would have produced more of a buzz sound but this is
probably my next step. Hopefully someone can enlighten me as to a
possible cause!




--
RickH

When my 29 was new in 2006, I had maybe the same noise around 95-100 kts. When I got home from the Nationals, I removed the rudder and really bent the mylar over. Used a small wood block and even creased it at almost a 90 degree angle. Reinstalled the rudder and the noise went away.
Then several years ago, installed new mylar. Didn't crease it over. Flew it and the noise came back. Came home, removed the rudder and bent it over using again a small block of wood to crease it and the nose went away. Several other folks with the same noise simply trimmed the mylar down from the top by an inch or so. The bottom they trimmed up. Their noise went away.

Best. Tom #711.

Thanks Tom, that sounds promising as well as some of the other tips regarding sealing around the rudder cable faring. I do have the MN exhaust and I glassed up the edges of the cockpit exhaust collector so it seals tightly. Wing gap seal tape is good all around as well, so directing my attention to the tail is probably the best bet. I had a 27B before my 29 and it had the MN cockpit exhaust as well. It was quiet all the way up to as fast as I dared take it! Thanks again for the comments, at least I don't feel that I have a one-off now-

Rick
NR

[Jim White[_3_]]

When my 27 was refinished Aerospool fitted seals below the bottom hinge
which were not there before. Now my glider 'farts' if I do not have the
rudder bang on straight.

I quite like the feedback!

Jim

[[email protected]]

Love the feedback on this subject. Probably not your problem but on my Ventus B, I was getting a buzz/ rattling noise from the tail area. Turned out to be the cheap read junk replacement tail wheel I put on it last winter. The junk roller blade wheel was falling apart at the hub where the bearings go in and was very loose on the bearings causing it to rattle and shake while flying. Should have new wheel today. I temp fixed it with fibrous tape around the bearings but the wheel has/is getting worse. Your results may vary..

[Dave Nadler]

Yuh know, if its only happening at 100-110 knots,
watcha doing flying so wimpy slowly???
Jest sayin...

[Robin Clark]

There is an access hole in the bottom of the rudder about the size of the mouth of a coke bottle. Seems obvious to try taping it, but I don't see it mentioned.

[Tom Claffey[_2_]]

I had this last season and fixed by adding V seals to the fin each side of
the
rudder.


At 14:37 12 June 2016, RickH wrote:
>
>I hope some of you ASG-29 drivers have either experienced or heard o
>this issue I'm having with my 2012 ASG-29. The ship has about 200 hour
>on it. At about 100-110 knots I have a very loud and annoying soun
>that comes from the rear of the ship. It sounds just like someon
>blowing over a coke bottle to create a tone. I can get rid of the soun
>by applying a little rudder although the yaw string is running tru
>while the sound is being generated. Rex Williams said he thought it wa
>the tail dump opening. I've put duct tape over the tail dump valve an
>still have this annoying tone accelerating through 100-110 knots. Joh
>Murray thought that it was the gap seal tape on the rudder. I woul
>have thought that would have produced more of a buzz sound but this i
>probably my next step. Hopefully someone can enlighten me as to
>possible cause
>
>
>
>
>--
>RickH
>

[Andreas Maurer]

On Sun, 12 Jun 2016 15:37:46 +0100, RickH
> wrote:

>
>I hope some of you ASG-29 drivers have either experienced or heard of
>this issue I'm having with my 2012 ASG-29. The ship has about 200 hours
>on it. At about 100-110 knots I have a very loud and annoying sound
>that comes from the rear of the ship. It sounds just like someone
>blowing over a coke bottle to create a tone. I can get rid of the sound
>by applying a little rudder although the yaw string is running true
>while the sound is being generated. Rex Williams said he thought it was
>the tail dump opening. I've put duct tape over the tail dump valve and
>still have this annoying tone accelerating through 100-110 knots. John
>Murray thought that it was the gap seal tape on the rudder. I would
>have thought that would have produced more of a buzz sound but this is
>probably my next step. Hopefully someone can enlighten me as to a
>possible cause!


I just had this case with the 29 of a friend.
It turned out that the gap seal of the gear doors was loose. Replacing
it fixed the problem immediately.

Cheers
Andreas

[Tom Claffey[_2_]]

I had this last season and fixed by adding V seals to the fin each side of
the
rudder.


At 14:37 12 June 2016, RickH wrote:
>
>I hope some of you ASG-29 drivers have either experienced or heard o
>this issue I'm having with my 2012 ASG-29. The ship has about 200 hour
>on it. At about 100-110 knots I have a very loud and annoying soun
>that comes from the rear of the ship. It sounds just like someon
>blowing over a coke bottle to create a tone. I can get rid of the soun
>by applying a little rudder although the yaw string is running tru
>while the sound is being generated. Rex Williams said he thought it wa
>the tail dump opening. I've put duct tape over the tail dump valve an
>still have this annoying tone accelerating through 100-110 knots. Joh
>Murray thought that it was the gap seal tape on the rudder. I woul
>have thought that would have produced more of a buzz sound but this i
>probably my next step. Hopefully someone can enlighten me as to
>possible cause
>
>
>
>
>--
>RickH
>

[[email protected]]

On Thursday, June 16, 2016 at 6:15:07 AM UTC+2, Tom Claffey wrote:
> I had this last season and fixed by adding V seals to the fin each side of
> the
> rudder.
>
>
> At 14:37 12 June 2016, RickH wrote:
> >
> >I hope some of you ASG-29 drivers have either experienced or heard o
> >this issue I'm having with my 2012 ASG-29. The ship has about 200 hour
> >on it. At about 100-110 knots I have a very loud and annoying soun
> >that comes from the rear of the ship. It sounds just like someon
> >blowing over a coke bottle to create a tone. I can get rid of the soun
> >by applying a little rudder although the yaw string is running tru
> >while the sound is being generated. Rex Williams said he thought it wa
> >the tail dump opening. I've put duct tape over the tail dump valve an
> >still have this annoying tone accelerating through 100-110 knots. Joh
> >Murray thought that it was the gap seal tape on the rudder. I woul
> >have thought that would have produced more of a buzz sound but this i
> >probably my next step. Hopefully someone can enlighten me as to
> >possible cause
> >
> >
> >
> >
> >--
> >RickH
> >

I had this sound on my asg29 as well. I managed to fix it by applying V seals on both sides of the rudder.
Gintas Zube
Lithuania

[[email protected]]

Same as Gintas, put internal V seals each side of rudder opening.
Tom
....