Funny humming sound?

Heard a high pitch, high frequency humming sound while over the Blue Ridge Mountains Monday.
Conditions: VFR, mild turbulence
Airspeed 156 KTS
Weight 1519
Pilot 156
Passenger 210?
fuel 23 gal (138#)

After flight inspection showed no problems.
Elevator trim looks fine.

Was this possibly elevator flutter?

Daddyman
N262 DF
dues paid 5/14

No its not elevator flutter. Canopy skirt or maybe trim tab?

humming

I fought this problem for a while and finally found that the upper intersection fairings were not fitted to the fuselage and wing tight enough. I found it by removing the fairings before a flight to NC. I fiberglased several layers of cloth on the inside of each fairing where they meet the fuselage and wing and sanded them down for a tight fit. The sound disappeared. Take a look at yours and see how tight they fit. It may be the problem.

Headset on ?
Not hearing the alternator are you? If airframe for sure, follow the path suggested earlier.

Sid,
Thanks.
I thought it could be the trim tab.
It is electric, but looks fine.
Daddyman

Mine too...canopy skirt

I was over the Blueridge this weekend also, but no buzzing sound! I had same issue a couple years ago, usually only above 150Kts and always in long "downhill" runs from altitude. I quickly pinpointed it to the back of the canopy skirt right at the centerline where it would barely touch the skin. I put a little foam tape under it for test purpose and no more buzz. Forgot to do the permanent fix, and it came back a couple weeks later..foam piece fell off. I now have a little rubber "bumper" there. Yours may be different, but when mine "buzzed" it really got your attention.

Interesting how airplanes always sound strange over mountains and water

Bird

Wing root fairing rubber?

Very good Idea.
I knew I had a "leak" there as wind blows in.
I left it alone as a poor man's air conditioner, but will seal it up.

Thanks,
Daddyman