bsacks05
Well Known Member
My -9 had a whistling problem so bad that people on the ground said it sounded like a turbine when I was on downwind.
That is not the sound I want coming from my RV.
Turns out it was coming from the empenage hinge openings. I guess the 9/9A tail surfaces are so big that the sound resonates and gets amplified. I know of one other -9 with that problem. Anyway, some Van's UMHV(sp) tape did the trick.
That is not the sound I want coming from my RV.
Turns out it was coming from the empenage hinge openings. I guess the 9/9A tail surfaces are so big that the sound resonates and gets amplified. I know of one other -9 with that problem. Anyway, some Van's UMHV(sp) tape did the trick.
I posted a little while ago about this whisling sound on my RV9a, because I have the same problem. Nobody knew what the problem was. I thought it was the resonance of the step. I was thinking to solve it by changing the resonance frequency of the step, by filling it with foam etc. The sound was mostly heard at about 130 kts. Now you found the cause of this annoying sound. hurray for you...I will plug that hole and will have a "quiet" aircraft. Another puzzle solved I think. Well done for your research and thanks so much. 
