I was just doing some polar math.

Let's say I'm on a Mc = 0 final glide in my ASW-27B.
I cross the finish cylinder boundary at 500' and 60
knots (best L/D dry). I'm now 1 sm from the airport
center. I fly at best L/D and reach the airfield with
about 380' of altitude. This is about the same altitude
I'd have if I'd crossed a finish gate at 100 knots
and 50 feet then pulled up.

If on the other hand I cross the cylinder at 150 knots
and 500' I will reach the airfield at 50', still at
150 knots. After my pullup I will have something more
than 900'. I know which scenario I prefer.

It's all about total energy. If you think total energy
is more about 500' of altitude than an extra 90 knots
of airspeed I suggest you do the math.

My suggestion is to keep these issues the domain of
the CD and contest organizers. They understand best
the local airport and traffic patterns and the nature
of the local conditions. Low total energy finishes
should be (and are) subject to penalty at the CD's
discretion. It's easy enough to judge off of GPS logs
now.

9B

At 00:00 12 March 2005, Eric Greenwell wrote:
wrote:
First, when do you pull in a cylinder finish?

How about when it's clear? There's no hurry, unlike
being 50 feet off
the ground.

When the
gps goes beep? How do I know mine will go beep in
sequence with yours?
What if I delay my pull?

I'm guessing you'd continue in the direction you are
headed. Since you
are 500' in the air, this shouldn't cause any heartburn.

What risk am I taking? What are the speed
differentials among the gliders in the gaggle? With
a finish line, high
and low energy aircraft separate naturally.

You'll have to explain how this happens. I've seen
high and low speed
gliders close together at finish lines, and if the
high speed glider is
lower than the others, watch out! He's eager to climb
up to pattern
height and isn't going to coast along for another 1000'
or so.

Will the pilot above and
behind me pushing to redline notice I'm in front flying
at best L/D in
an attempt to avoid missing the bottom of the cyliner?

He's safe - he'll separate from you when he pulls up,
and you aren't
going to pull up. That's a good situation. It seems
unlikely he won't
see you ahead of him as he approaches. I've seen the
same situation
finish gates, anyway.

And where is the
cylinder? Why, it's right there on my instrument panel!
Next to the
altimeter, my other sore distraction.

I think if you can keep track of the other gliders
zooming into a finish
line from various altitudes and angles, you'd be able
to manage a finish
cylinder. At least, as you approach the cylinder, the
gliders that will
enter the cylinder near you are all going the same
direction you are,
which is often not true at a finish line.

When was the last time we wanted to ban gaggles for
safety reasons?

I think most of us have wanted to elimanate *large*
gaggles, but no one
has figured out a good way to do it.

My theory is that ignorance shows more profoundly
low and fast than
high and slow.

If by ignorance, you mean 'poor judgement', I agree
with you, and I
think this is the theory behind the finish cylinders,
isn't it?



--
Change 'netto' to 'net' to email me directly

Eric Greenwell
Washington State
USA