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Old November 21st 04, 03:14 PM
Chris OCallaghan
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Default Water, water, everywhere, but none for thirsty wings....

I was surprised that Karl's column in the November issue of soaring
hasn't generated any comment. To start the thread, I'll point out an
important fallacy in Karl's argument.

Karl suggests that water is unnecessary: a complicating factor in a
sport that only gives advantage if one pilot can achieve a higher wing
loading than another. This would be very true if, and only if, you
were unable to dump water. But as it happens, each pilot is given the
choice of keeping none, some, or all of his water during a flight.
This represents a variable that, based on a pilot's decisions, can
have significant outcomes on his average speed.

Here's an example. A long task is called. Pilots predict a strong day
and load to max gross. But an early start in less favorable conditions
is required to guarantee completion. Several pilots choose to fly
aggressively, then find themselves low in weak conditions on the first
leg. To avoid landing, they must dump their water, effectively
lowering their average speeds by 5-10 knots throughout the next 75% of
the flight. They have effectively removed themselves from competition
for the day. Pilots who exercised greater care were able to keep their
water into the strongest part of the day.

Based on this example, it is clear that having disposable ballast on
board increases the number of variables a pilot must assess in his
decision making. In other words, it is not "reducible" to a constant
as Karl has suggested.

We are enjoying increasing interest in racing, thanks in great degree
to Karl's efforts. The sports class presents a venue for those pilots
who would prefer to reduce the variables. But the racing classes are
all about decisions. Wing loading limits are a good idea. But removing
critical competitive variables for the sake of convenience would
diminish the sport for those of us who find its marvelous complexities
ineluctable.

I remain a proponent of weight restriction for safety's sake. But
management of disposable ballast remains a critical aspect of
competitive decision making.

As for the extra effort of loading water, I've driven up to 40 hours
each way to participate in a national soaring contest. The extra 30
minutes I spend each of the ten contest days watering the glider
doesn't even register on the convenience meter.

OC