2005 SSA Handicaps Posted

http://sailplane-racing.org/rules.htm

Ken Kochanski
SRA Secretary

no listing for the following

ASW22-A 24meter
ASW22-A 22meter

Al

As I think about a 24 meter glider, I wonder how much
span is too much?

At some point, the roll rate of a long span must just
be terrible. And there is added wetted area, right?


There are other disadvantages too (assembly, runway
width, etc.) that have nothing to do with flight in
the air too, I suppose.

I can see how lots of span is fine if you are willing
to add enough water, but 24 meters seems like a LOT
of wing.
Once L/D goes beyond a certain point (40 or 50 or whatever)

it seems like updrafts and downdrafts and penetration
become a much better indicator of performance than

strictly L/D.

The pilots who DON'T buy langer spans but have plenty
of money to do so are buying shorter spans for some
reason.
Is it mostly the ground factors, or is there a pretty
'natural' cutoff? Single seat vs. 2-seat I can understand,
and maybe some extra wing for those pilots who are
a bit
heavier, but 24 meters seems REALLY long to me...

At 21:00 15 April 2005, wrote:
no listing for the following

ASW22-A 24meter
ASW22-A 22meter

Al


Mark J. Boyd

M B wrote:
The pilots who DON'T buy langer spans but have plenty
of money to do so are buying shorter spans for some
reason.
Is it mostly the ground factors, or is there a pretty
'natural' cutoff? Single seat vs. 2-seat I can understand,
and maybe some extra wing for those pilots who are
a bit
heavier, but 24 meters seems REALLY long to me...


Increasing span changes your style of flying, and this is one reason why
pilots don't buy as much span as they can afford. My recent step up from
15m to a princely 17.7m made a surprising difference in the kind of
flying which was most effective, and having once flown with Brian
Spreckley in an ASH25 I can say that this much span gives vastly more
difference from 15m.

Big wings (in my case, "just a bit bigger" wings) don't suit everyone,
and even 18m can feel uncomfortable or unnatural for those pilots who
like snappy handling.

Chris Reed

'Course if you start out with a Stemme (23 meter), then an ASH26E (18 meter)
feels almost like driving a Honda S2000!

bumper

"Chris Reed" wrote in message
...

Big wings (in my case, "just a bit bigger" wings) don't suit everyone, and
even 18m can feel uncomfortable or unnatural for those pilots who like
snappy handling.

Chris Reed

M B wrote:
As I think about a 24 meter glider, I wonder how much
span is too much?

At some point, the roll rate of a long span must just
be terrible. And there is added wetted area, right?


There are other disadvantages too (assembly, runway
width, etc.) that have nothing to do with flight in
the air too, I suppose.

I can see how lots of span is fine if you are willing
to add enough water, but 24 meters seems like a LOT
of wing.
Once L/D goes beyond a certain point (40 or 50 or whatever)

it seems like updrafts and downdrafts and penetration
become a much better indicator of performance than

strictly L/D.

The pilots who DON'T buy langer spans but have plenty
of money to do so are buying shorter spans for some
reason.
Is it mostly the ground factors, or is there a pretty
'natural' cutoff? Single seat vs. 2-seat I can understand,
and maybe some extra wing for those pilots who are
a bit
heavier, but 24 meters seems REALLY long to me...

At 21:00 15 April 2005, wrote:
no listing for the following

ASW22-A 24meter
ASW22-A 22meter

Al


Mark J. Boyd

25.5 m on my Nimbus 3 and I have never even bothered to fly it in the
22.5 m short mode without the tips on! The roll rate is not 'terrible'
but it does take some getting used too! Unfortunately our field is a
little short so I can't load it to the gills but on anything but a
winters day it really needs a couple of barrels of juice in the wings.

Given enough funds I might go to a HP 304S - 18T. I have always liked
their ships and the 304S looks like another winner and yes ground
rigging is pretty much all of the reason for moving over.

Someone else has already pointed out that longer span changes the way
you fly. There was a comment somewhere about flying the Eta ( 30m span
) 'when in doubt climb in a straight line'. Thats how the big open
ships seem to get around.

The 18m class ships have most of the L/D of the Opens but the reduced
span and modern aerodynamics retain most, if not all of the 15m
maneuverability. In European conditions I doubt whether most open ships
can run away from a new 18m ship. However when it dies late on a good
day its really nice to throttle back to best glide and be able to
average in the 60's for the last 50 or 60km through a sea-breezed final
glide area.


Ian

Mark,

As one qutoe says, "There is No Substitute for Span." Then, some Bird
came along and said "There is a Substitute for span. It is called
Talent. But you can buy Span!"

Handling qualities are relative. If you are looking for a ship to do
acro in, I would not recommend an ASH-25. Of the big ships I am aware
of, the handling is not bad. Just slower in roll. Forces are still
generally light. And they take more work to fly well in circles. But
as some pilot here in the US said when someone complained about how the
Ventus requires lots of effort to fly, "A REAL pilot does not have any
trouble flying a Ventus."

Ground rigging is probably the biggest reason for people not liking to
deal with the open class ships. Face it. Most have six pieces of wing
to attach. No matter how bad your two piece wing might be, it will
probably take less time to assemble than a six piece wing. Runway
width can be an issue, as we generaly will hang out near or over lights
on both sides of the runway. Know your airplane and you can offset one
way then lower the other wing.

As for performance, I personally think they have gotten too big. Look
at the Schleicher site on the ASH-25. Partly marketing, but they make
the comment that higher minimum wing loadings do not seem to hurt the
open class gliders. And with a 750 KG weight limit for contests, the
current open class ships are stuck at under 9.5 psf. The Nimbus 4 is
about 8.7. Read what others have written, and almost all of them want
more weight.

I came up with the idea that best L/D can be approximated by Span in
Meters plus Aspect Ratio. This generally gets you within about 10%,
except on the new 15 meter class ships, where it falls a bit short of
the claims by the factories. If the span was cut back to, say 22
meters, and the aspect ratio run up to about 40 (heck, Eta is 51,and
the long tipped 25's are pushing if not above 40, but with 26 plus
meters of span), that puts the area at about 130 square feet. Chords
would be similar to an ASW-27, but over longer sections between the
taper breaks.

Now, if my ultra preliminary estimation for performance holds true, you
would have about the same best L/D (22 + 40 = 62) as a N4, but you
could ballast up to about 12.8 psf at 750 KG. Wouldn't that make for a
rocketship! And if you could keep the minimum wingloading to about
8.5, this leave about 900 lbs for the empty weight (200 lb pilot).
Seems doable to me at a first glance.

Of course, this view is US Based. In Europe, there doesn't seem to be
the desire for the ultra-high wing loading. And do you think any
manufacturer would put out a smaller Unlimted Class ship than what they
have now? Not bloody likely.

So, is 24 meters too much? Maybe, for the US and the weight
restriction. You might do better with less. I see lots of pictures
of German registered ASH-25s that have been stretched, some to as much
as 27 meters. So, I am suspecting that L/D max is more important than
the ultra high speed cruising in Europe. That, and the crossover for
the longer wings is above the often used cruising speeds.

And just to confuse things, I have a 604 that I am looking to stretch
from 22 to 24 meters. Being in the more sedate, flat lands, I am
looking for more low end performance, and hoping the cross-over will be
above my typical crusie speeds.

But, if you know of anyone willing to part with an ASH-26 fuselage, I
could get started on a set of thin, 22 meter wings to try and prove my
point... Could be intersting to plan a 40:1 final glide at 115 knots,
no wind.

Steve Leonard

Steve Leonard wrote:
But as some pilot here in the US said when someone complained about
how the Ventus requires lots of effort to fly, "A REAL pilot does
not have any trouble flying a Ventus."

I prefer: a REAL pilot understands his or her own current limitations,
and flies a ship that fits them...

Steve Leonard wrote:

Ground rigging is probably the biggest reason for people not liking to
deal with the open class ships.

Although it's exactly the same work to attach the 18m as the 15m
winglets to the LS8, I always fly 15m. It's just nicer, quicker, more
"sportive".

Of course, this view is US Based. In Europe, there doesn't seem to be
the desire for the ultra-high wing loading.

I know many pilots which always fly fully loaded. Not me. They like the
speed. I prefer to feel the thermals better. But then, I don't fly
competitions.

And do you think any
manufacturer would put out a smaller Unlimted Class ship than what they
have now? Not bloody likely.

There's the new Antares with 20m.

Stefan

Steve Leonard wrote:
And do you think any manufacturer would put out a smaller Unlimted
Class ship than what they have now? Not bloody likely.

Stefan wrote:
There's the new Antares with 20m.

Exactly. The Antares is from a NEW manufacturer. Not someone that
already has a 22 or 24 meter span Unlimited class sailplane. It is a
motorglider. And what is the span of a lot of the current generation
of motorgliders? 18 meters, if I remember correctly. Yes, there is
the N4M, and ASW-22BLE at well over 20 meters, but there is also the
LS-9, DG-800, ASH-26E, Ventus 2CM at 18 meters.

Some like span, some don't. I personally like span. I must be lacking
in the "skill" department ;-)

Steve