Video of using up ALL of the runway on a wet aero tow
John,
Do you always takeoff with full ballast? In my ASW19 I always had full
water or no water so a wing low cross wind takeoff was normal. *With
the 28 I'm never full and I'd rather be ballanced and stay ballanced
than have the wing low.
If the wing runner really understood what was going on then holding
the wings level until start of the roll and then lowering slightly may
work but I'm usually happy to find a wing runner that understands the
need for balance and a fast run.
What do other do for cross wind takeoffs with partial ballast?
Andy
No, I am of the school that puts in exactly the amount of ballast I
want for the day rather than takeoff full and dump. I like to really
know what I have and get the tail tank ballast just right. Dealing
with partially full tanks on a ship with tanks -- baffles -- is not as
much of a problem as it is with bags. Also, there are times when it's
much harder to get off the ground with full water than with half
water.
In 99% of conditions, I agree -- sloshing the tanks so that there is
no pressure is the right thing to do, no matter what the wind. This is
especially true with the most common trouble scenario, high altitude,
hot temperature, contest, weak towplane, cross-downwind but they don't
want to change runways. Hobbs and Tonopah have been memorable. If it's
balanced, you can get past the zone of no control more quickly.
The 1% problem is a really strong crosswind. Then, getting the wing
runner to first slosh and balance, then lower the tip a bit just when
starting the run will help. Lack of aileron authority isn't so much of
a problem, but avoiding a strong wind-driven force in the wrong
direction is. Better to be slightly heavy in the upwind side. Maybe
that just ensures that it's NOT banked in the wrong direction. Mifflin
on a really strong ridge day is an example.
Wing runners often don't realize when wings are level or not --
winglets seem to confuse them, as does a cross-runway slope at the
takeoff point. The difference between gliders with lots of dihedral
(duo) and none (27) confuses them, as they get used to holding the tip
in the same place on their bodies. They won't understand sloshing the
water to get it through the baffles, and the importance of taking off
with no pressure on the wing unless this is explained. And they often
don't understand the importance of running, hard, in a low or downwind
situation with full water. Without pulling or pushing on the tip.
Many get used to what works with no water and headwind at the home
airport, and don't adapt. And it's hard to explain all this, quickly
and politely, on a contest grid.
Last comment -- towplanes. It's common in contests to bring in
towplanes that have been ferrying 2-33's all season long. They take
off and head for the sky while the glider is still on the ground or in
ground effect. This is especially hard for standard class gliders with
inadequate angle of incidence. The maneuver is as explained in someone
else's earlier post -- the tow plane should take off as normal, but
stay low until it has reached tow speed. You know you're headed for
trouble when the chorus of "more speed" erupts from glider after
glider.
John Cochrane
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