Effect of rain on gliders in flight

At 00:02 28 April 2009, wrote:
I also did some of my initial training in a 2-33 in the rain.
Naturally a light steady rain with good visibility, not associated
with unstable air. One thing nobody has mentioned is the sound. Even a
light rain sounds like someone is throwing BB's at the canopy.

I've also had to deal with rain while out on course on a cross-country
flight, and my glider has the same airfoil as a PIK-20. I've
thermalled to cloudbase more than once in a steady rain from lake-
effect cumulus (with full water ballast). I've also had to ridge soar
through heavier rain that ran across the wing in sheets (the boundary
layer water flow was mostly laiminar, the airflow not so much). And I
used a rain street to run upwind and get home late in the day. But
I've also landed out just a few miles from home when a summer thermal
street overdeveloped and started raining on me. So there is a
performance hit from rain, but it does not necessarily mean the end of
your soaring day. In fact, one promising soaring day almost looked
like a bust, until we realized the rain over the airport was falling
from a massive wave cloud--we towed upwind out of the rain, and had an
amazing wave flight.

On Apr 27, 4:40=A0pm, Mike the Strike wrote:
On Apr 27, 11:29=A0am, "
wrote:





Then again, if you are training in a 2-33, a little rain will
probably
increase your performance by washing some of the bugs and dirt off!

Seriously, in a non-laminar wing (any metal trainer, pretty much),
especially if it hasn't been waxed recently (and who waxes a 2-33 or
a
Lark!), light rain will have no aerodynamic effect. =A0Biggest
problem
will be reduced visibility through the canopy, and less braking
action
if you land on grass.

Obviously, stay away from heavy rain showers or thunderstorms, but
pattern-bashing in a light, occasional drizzle beats watching birds
fly.

Good training, too.

Kirk

Kirk beat me too it! =A0When you have an ugly crinkled metal wing
bristling with rivets, a few raindrops are hardly going to matter from
an aerodynamic perspective.

The most important consideration is the type of cloud overhead
producing the rain. =A0Out here in the US west, there's a good chance
it'll be a shower cloud or thunderstorm that may produce downdrafts
and lightning - things to worry about a lot more than a few raindrops.

If you are in western Europe where most of the rain comes from
stratiform clouds, it's not so bad. =A0Heck - if you live in some of
the
countries with the worst climate (Britain for example), flying in the
rain is a necessary skill!

Mike-

When you encounter precip you are likely to experience sink to one extent
or another because of the cooling effect of droplets or crystals that have
a relatively large surface area or just the natural effect of
precipitation entraining some local air as it descends. But as long as you
are dealing with the stable air type of precip--drizzle or flurries--its
unlikely to be noticeable