Sailplane Classes - a different perspective

Eric Greenwell wrote:
There is an 18 meter class in the USA, the FAI 18 meter. The 18 Meter
Nationals will be at Montague, California, in 2005. I don't know of any
Regional 18 M class being scheduled.

We had a successful (7 total, 4 motorgliders) 18M class in the Region 11
FAI contest at Minden last year, and we'll likely do it again next year.

Marc

You need another, better reason to launch
this revolution. (:-D


Another requirement for change is popular support...I
will be verrry generous and estimate the entire glider
racing population in the US at 10% of SSA members...1400
pilots. I suspect 500 pilots is a more accurate number,
but not wanting to debate this I will use the larger
number.

How many of them see this as an issue? Does redoing
the class requirements solve the issue of driving halfway
across the USA to sit on the tarmac waiting for the
rain to stop? Or reduce the time expenditure to do
that?

And if a handicap system is not used...then an arms
race starts with pilots spending big bucks to buy performance.
I admire the enthusiasm racers have for their niche.
But I don't see your suggestion increasing the numbers.
And Sparrowhawks probably will do quite well in Sports
Class.

At 01:00 28 November 2004, David Bingham wrote:
Sailplane Classes

snip


If you don't believe me go and demo a
SparrowHawk.
Dave


Dave, they won't let anyone unless the person plunks
down a non-refundable chunk of money on a purchase
order. No flights by an insured pilot/instructor or
whoever.

Earlier, (David Bingham) wrote:

...I propose that:
Class 1 be limited to 70kilos maximum
(plus safety equipment such as a ballistic parachute).
Class 2 be limited to 250kilos max

Class 3 be limited to 250kilos minimum...

So, if these classes were suddenly instituted tomorrow, would you compete in them?

Bob K.

Bob Kuykendall wrote:

So, if these classes were suddenly instituted tomorrow, would you compete in them?

If there was a Sports Class competition nearby, that's the one I'd most likely
compete in.

The year I had the most time and interest, there was unfortunately no
Sports Class at Avenal. Too bad

--

------------+
Mark J. Boyd

Hi Gang
For approximately 30 years the performance of gliders has hardly
advanced at all and yet we now have the tools (computer programs) and
much stronger materials (carbon composites) to surely advance the
state of the art of gliders. Has this happened? Yes there are marginal
improvements but so small. What's the reason for this slowdown in
innovation? I believe in no small part it is due to the sailplane
classes. With the establishing of the classes that are so rigid and,
in my mind, so restrictive, innovation has suffered. What a breath of
fresh air the SparrowHawk is! However there is no sailplane class for
it. So I got to thinking. Is the present setup of the classes
rational, reasonable? Could a better system be envisioned? OK, taking
this further if there were no classes today, and it was suggested to
set up classes, what would they look like? I think closer to what I'm
suggesting than what they are now. I hope my posting keeps the gang
thinking.

A couple of specific comments:

It is true Greg Cole required me to write him a check before demoing
the SparrowHawk but he also told me he would return the check if I
didn't like it.

Bob K wrote:
"So, if these classes were suddenly instituted tomorrow, would you
compete in them?"

A tough question. I just might participate in a class 1 competition
if were held close to home.
Dave

"David Bingham" wrote in message
...
Hi Gang
For approximately 30 years the performance of gliders has hardly
advanced at all and yet we now have the tools (computer programs) and
much stronger materials (carbon composites) to surely advance the
state of the art of gliders. Has this happened? Yes there are marginal
improvements but so small. What's the reason for this slowdown in
innovation? I believe in no small part it is due to the sailplane
classes. With the establishing of the classes that are so rigid and,
in my mind, so restrictive, innovation has suffered.

(Snip------)

Yep.

The first class, (Standard Class) was intended to reduce glider costs by
virtually eliminating innovation which, it was felt at the time, was leading
to ever larger and more expensive gliders.

The flap enthusiasts insisted on splitting off as the 15 meter class.

Both classes became successful at the expense of the open class where carbon
composites make the most difference. In a 15 meter design, the main benefit
of carbon is lighter wings for easier assembly.

Manufacturers were forced to produce special gliders for two similar 15
meter classes. Designers were forced by the same class rules to pursue ever
more expensive ways to improve performance such as extremely smooth
surfaces. They wound up producing expensive gliders anyway because of short
production runs.

It's interesting to speculate what would have happened if the competition
organizations had resisted creating competition classes. Innovation would
have run free. It's even possible that large span, ultra-high performance
gliders would be priced the same as 15 meter gliders are today because of
much larger production runs.

I've heard interesting speculation that there's a 'natural best span' around
18 - 20 meters that would be the best compromise for all conditions. If the
market had settled on that, we might have had innovation AND low costs.
We'll never know.

Bill Daniels

p.s. I recently listened as a 'pundit' was holding forth on the reasons for
the demise of the open class. He was saying that they were just too hard to
rig. A short distance behind him an ASH-25 owner was whistling softly to
himself as he rigged solo using simple aids.

Bill,
I think you have a solid point. i've been re-reading for the 8th or 10th
time Fred Thomas' book on sailplane design and some of the information on
cross country speed vs span mskes it look like the sweet spot is somewhere
in the 18-20 meter range, just as you say.
Cabon makes the wings lighter and easier to rig that's for sure and maybe
more stable dimensionally.
Thirty meters seems excessive but we would all like to experience "wretched
excess" for the pure fun of it once in a while and 13 meters seems just
excessively limiting (at least to me).
Cheers!

"Bill Daniels" wrote in message
news:ff4rd.181115$R05.60069@attbi_s53...

"David Bingham" wrote in message
...
Hi Gang
For approximately 30 years the performance of gliders has hardly
advanced at all and yet we now have the tools (computer programs) and
much stronger materials (carbon composites) to surely advance the
state of the art of gliders. Has this happened? Yes there are marginal
improvements but so small. What's the reason for this slowdown in
innovation? I believe in no small part it is due to the sailplane
classes. With the establishing of the classes that are so rigid and,
in my mind, so restrictive, innovation has suffered.

(Snip------)

Yep.

The first class, (Standard Class) was intended to reduce glider costs by
virtually eliminating innovation which, it was felt at the time, was
leading
to ever larger and more expensive gliders.

The flap enthusiasts insisted on splitting off as the 15 meter class.

Both classes became successful at the expense of the open class where
carbon
composites make the most difference. In a 15 meter design, the main
benefit
of carbon is lighter wings for easier assembly.

Manufacturers were forced to produce special gliders for two similar 15
meter classes. Designers were forced by the same class rules to pursue
ever
more expensive ways to improve performance such as extremely smooth
surfaces. They wound up producing expensive gliders anyway because of
short
production runs.

It's interesting to speculate what would have happened if the competition
organizations had resisted creating competition classes. Innovation would
have run free. It's even possible that large span, ultra-high performance
gliders would be priced the same as 15 meter gliders are today because of
much larger production runs.

I've heard interesting speculation that there's a 'natural best span'
around
18 - 20 meters that would be the best compromise for all conditions. If
the
market had settled on that, we might have had innovation AND low costs.
We'll never know.

Bill Daniels

p.s. I recently listened as a 'pundit' was holding forth on the reasons
for
the demise of the open class. He was saying that they were just too hard
to
rig. A short distance behind him an ASH-25 owner was whistling softly to
himself as he rigged solo using simple aids.

Bill Daniels wrote:

The first class, (Standard Class) was intended to reduce glider costs by
virtually eliminating innovation which, it was felt at the time, was leading
to ever larger and more expensive gliders.

And it worked! Standard class gliders were a lot cheaper!


The flap enthusiasts insisted on splitting off as the 15 meter class.

Both classes became successful at the expense of the open class where carbon
composites make the most difference.

Wait a minute - these classes came into being years before carbon was
used. The first really successful Standard Class glider, the Ka-6, was wood!

In a 15 meter design, the main benefit
of carbon is lighter wings for easier assembly.

Also a higher aspect ratio leading to better L/D, and thinner wings,
leading to higher cross-country speed.


Manufacturers were forced to produce special gliders for two similar 15
meter classes. Designers were forced by the same class rules to pursue ever
more expensive ways to improve performance such as extremely smooth
surfaces. They wound up producing expensive gliders anyway because of short
production runs.

Baloney! Far more gliders in EACH class were produced than ever would
have been produced for even a single Open class. THe classes weren't
popular because they were FAI classes, but became popular because they
were such an outstanding combination of cost and performance. That
magical "sweet spot" some people talk about.

snip

I've heard interesting speculation that there's a 'natural best span' around
18 - 20 meters that would be the best compromise for all conditions. If the
market had settled on that, we might have had innovation AND low costs.
We'll never know.

The market is moving there, to some extent. Remember, the 'natural best
span' is _very_ dependent on the materials available (and their costs),
and will be different for wood, metal, fiberglass, and carbon. There is
nothing magic about 18 meters, because it depends on a value judgment
(performance versus costs). So, the market couldn't settle on 18 meters
sooner, but had to wait for technology to advance, material costs to
come down, and for pilots to decide that they were now willing to pay
for a certain level of performance.

A lot of ras pilots seem to think 15 meters is the 'natural best span',
when embodied in a low cost LS4.


Bill Daniels

p.s. I recently listened as a 'pundit' was holding forth on the reasons for
the demise of the open class. He was saying that they were just too hard to
rig. A short distance behind him an ASH-25 owner was whistling softly to
himself as he rigged solo using simple aids.

And taking far longer than an ASW 27, which cost far less. If your
pundit talked only about putting it together, he hasn't been around one
enough to know what a bloody pig it is on the ground, and how much real
estate they need just to be tied down, or pushed around on a ramp, or
taken down a taxiway, and how wide the runway needs to be to take off or
land on, the size of the towplane, and how many people had better show
up if he ever hopes to get it out of a field! Shucks, just trying to
push the empty trailer around to hook it up is more than my crew can
handle. It's not ignorance that keeps people from falling all over
themselves to get a 25 meter glider.

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

Eric Greenwell
Washington State
USA

Eric Greenwell wrote:

A lot of ras pilots seem to think 15 meters is the 'natural best span',
when embodied in a low cost LS4.


And as far as performance is concerned, look at was has been achieved
with the Diana, sticking with normal sized wings. Much more than a lot
of open class gliders.


--

Michel TALON