On Sat, 27 Jul 2019 06:32:03 -0700, gregv wrote:

Ok so I checked carefully the glider on the ground and I seems I could
reproduce the noise.

Lift Pins and bearings are ok, no rubbing clue on the spar neither on
the fuselage. The noise is not related to outer wings.

When the airbrakes are open, there is no more noise... so it must be
related to airbrakes... I can hear the noise coming from the airbrakes /
flaps, and if I put my hand on them as they are closed and that I put
the wing for and aft I can hear and feel the noise with my hand. When I
inspect the airbrakes mechanism everything seems ok. Strange thing is
that the noise is symetrical on both wings.

If that was my glider (I'm in the UK) I'd being asking the inspector who
does my Annual Inspection to take a look at it. Doing that in the past
has both found problems I've missed and shown that things I asked him
about were non-problems.


--
Martin | martin at
Gregorie | gregorie dot org