Effect of rain on gliders in flight

What are the implications about getting rained on in flight?
Obviously, if the ceiling is 2500 and overcast, this is primarily a
"training day." How should a glider pilot react to rain? How does it
affect the control of the aircraft?

How does one fly safely in the event or threat of rain?

--Michael


Most of the time, light rain is not going to be troublesome with
training flights as long as the visibility is good. However, take it
from one who knows: Even light rain can be accompanied by an occasional
downburst or or unexpected wind shear. You don't have to be actually
caught in the downburst itself. A downburst near the field can result in
a very rapid change in wind direction (shear). Not good if it catches
you on landing or takeoff. I was getting checked out in a glass 2-seater
for the first time. An instructor and I were doing takeoffs and landing
in a Grob. A little light rain had started falling. Almost now wind.
Ceiling was probably around 2000' but we were only towing to 800-1000.
We were on the takeoff run on what was to be my last dual flight that
day. We had just lifted off behind the Maul tug and airspeed was
indicating about 70 (don't remember if it was knots or mph).
Unexpectedly, the Maul plopped back down onto the runway, then we did
the same. I glanced at the airspeed and it was reading 40! Then I
noticed the trees tops whipping around. We were too close to the end of
the runway at that point to abort and the Maul went up over the low
trees at the end and we went with him. We immediately started descending
into the valley and picked up some speed. We got rolled around pretty
violently. The Maul driver got it more-or-less back under control,
managed to start climbing, and expressed his surprise that we had not
broken the tow rope in the turbulence. As we turned back towards the
airport, things calmed down. We had been caught in a reversal of wind
direction, apparently due to a downburst off the approach end of the
field.