soartech wrote, On 5/22/2013 10:20 AM:
What is lost without them? One point of glide? What about sink rate?
Is this just for racers? My glider does not have them.
Does anyone have any facts on this?
Thanks.

Are you asking about "seals" - a flexible material like tape between the
wing and control surface to prevent air from leaking between the two. It
might be external or internal.

Or, are you asking about "fairings" - generally Mylar across the top or
the bottom the wing/control surface gap to smooth the airflow across the
gap. The fairing is external only, and might also reduce the leakage
from bottom surface to top surface.

My glider came with both, but I have no idea of how much they affect the
performance. I know the top fairings can degrade the climb when they
lose their curvature after 10 years or so.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl