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