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Old April 30th 04, 10:34 AM
Don Johnstone
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Cant say about the Pik but I can tell you the Kestrel
does, and some. All the aerodynamic qualities of a
housebrick. Grob 103 not much better.
On the plus side an ASW 17 does not appear to be effected,
it climbs with wet wings, bonus if you fly in the UK.

At 02:30 30 April 2004, Arnie wrote:
Max,

Most gliders of that generation use the Wortmann FX
67 airfoil, which has
degraded performance when wet.
Some examples are :
Kestrel, DG-400, Pik-20, Nimbus 2, Lak-12, LS-3, Janus,
HP-18, Jantar 2B

Apparently some are worse than others, I suppose this
is due to the fact
that some use this profile on the wing roots only,
with another profile
towards the wingtips (these being 'better' or more
'tolerant'), while some
use only the FX-67 only. But it could be something
else.

Apparently the laminar flow is disturbed very easily
on this profile, so not
only water, but bugs will degrade their performance
as well.

Reading Dick Johnson's flight tests, especially some
from the 70s, will tell
you a little bit more about this.
If you go to this link (http://www.ssa.org/Magazines/Johnson.asp)
and scroll

down, there are 3 reports about the Pik-20, very illuminating.


'Matt' wrote in message
...
do they fall out of the sky when they get wet?