On Saturday, October 12, 2019 at 8:42:44 AM UTC-7, Armand Charbonneau wrote:
My Ventus 2c makes a howling sound when flying at 0 flap setting. It is significantly less noticeable immediately after changing the flap setting either positive or negative. Pilots tell me they can hear it when flying overhead or landing. I can hear it seemingly behind me, inside the cockpit. Gear up or down does not seem to make a difference.

The glider was refinished with poly in 2012, so I suspect the wing seals are seven years old. Otherwise the ship in very good condition and soars nicely.

Does anyone know what could be causing this sound? I can replace all the seals this winter, but they appear to be in good condition, except maybe on the tail plane.

I own and fly V2C s/n 51 and have never experienced that problem. I also find the cockpit reasonably quiet if everything is well sealed; even more so since having a Hank Nixon turtleback vent installed.

But what initially struck me about your question though, is your use of the 0 flap setting. My SH flight manual doesn't even acknowledge 0-flaps as a cruise setting. By virtue of that (and advice from other V2C pilots) I never routinely use it. It's just a transit point between positive and negative settings. Sorry, if I steer the conversation off-topic.