Bill Daniels wrote:

So, bright r.a.s people, how do you neatly and easily transport
ballast water to the glider if the gliderport doesn't have a tanker or
water hoses
on the ramp? Once you get it there, how do you get it into the
glider?

What infrastructure does your gliderport have? If there is not a tap
close enough at your local site, can you bribe the management to get
one installed? Get the other single seater pilots to contribute to the
costs.

I always carry a long (about 40m) 1/2" diameter garden hose in the
trailer and a collection of tap fittings (about 6) of different sizes.

Then I tow the glider with the one man reverse tow kit as close as I can
to a tap, select the required tap fitting, unwind the hose pipe and
"full it up". Winding up the hose afterwards is the biggest job. (It is
good manners to move the glider away from the tap ASAP when you tanked
up, as you are probably in somebody's way - usually the pilot in the
queue behind you).

When I had the Nimbus II I put the hose straight into the ballast tank
opening on the top of the wing. You have to full the wing supported
with the wing wheel first. I used a stop watch to time the fulling time
to get an estimate of how much water had gone in. This helps to get the
same amount of water in each wing. (But it was not a problem taking off
if the balance was not perfect).

Another approach is to full the tanks 'till they overflow, then dump
water for a timed release to get down to the required loading. This can
be done during tow or after release if your situation allows you to
take off with full tanks.

Just make sure you can't pressurise the wing tank. This will cause
expensive damage, very quickly. Putting a 3/4" hose into a S-H filling
port might not leave enough room for the overflow to get out fast
enough if you forget to stop the hose. A 1/2" hose is safe.

Now I fly an LS3. (Easier on the back) But is has bags not tanks, so I
use a funnel with a hose sized to plug into the dump vent on the bottom
of the wing. The funnel has a stand which holds it about 300mm above
hight of the cockpit. I put the garden hose into the top of the funnel.
The main function of this kit is to protect the wing from over
pressure. With the LS3 I have to hold the heavy wing in the air when I
start fulling the 2nd wing. In theory you need two people for this. I
can do it on my own - but it splashes a little. I don't bother to suck
the air out of the bags before filling, and I never quite get them 100%
full but that does not matter - I get enough water in to reach my
desired wing loading.

Keep your filling kit simple. The faster you get the water in, the
sooner you can launch and the more distance you can cover in the day.

Also, the easier it is to full the glider, the more often you will use
water and the better your "flying with water" skills will become. If
you only use water on those very special days, you won't be ready to
extract maximum advantage from the extra wing loading.

I usually take off with more water than the conditions warrent and dump
some when airborne.

Test dump a full load of water on the ground while watching carefully
and timing with a stop watch. Then you know how many seconds it takes
to dump all the water, and you get an idea how "linear" the dump rate
is by watching the outflow. Also note if both tanks dump at the same
rate - if there is a big discrepancy the dump valves may need
maintenance. Then count seconds while dumping in the air so as to have
an idea how much water is in board.

It may be worth doing one full from known capacity containers. Then you
can establish how much water you tanks can actually hold and confirm if
they both hold the same volume.

Ian


PS: The Nimbus II flies best when the water overflowing from the filler
valves and freezes into an icicle on the top surface of the wing -
because it's sitting at 18000' :-)