Flat Spin

No, the Pégase airfoil is a completely new airfoil designed by the French
ONERA. You would need to compare the Pégase to the ASW19 standard class, and
it must be stated the the performance of the Pégase is significantly better
than an ASW19.
Actually, flying an ASW20 against a Pégase in competition is quite a pain -
they climb very well, glide fairly well and have a much lower handicap
coefficient...

--
Bert Willing

ASW20 "TW"


"W.J. (Bill) Dean (U.K.)." a écrit dans le message
de ...
I have often wondered whether the Pegase airfoil is an entirely different
design to the ASW20, or whether it is basically a fixed flap version of
the
ASW20 wing.

I understand that the LS8 wing is a fixed flap version of the LS6 wing,
and the LS8 does seem to work rather well.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Bert Willing" wrote in
message ...

Well, the airfoil of the Pégase is French, the rest is a copy of German
design...

Bert Willing

Well, it's easy to say that German gliders are much more expensive than
French ones... Centrair didn't have to pay the development of the ASW20,
neither of the Pégase airframe, neither of the Alliance 34 (which, as SF34
was a complete flop in Germany, so I still don't see the reason that
Centrair took it up...).
Development cost of a glider makes for a significant part of the selling
price as you have to get the amortization from somewhere.
And sorry, if I look at the fleet of club ships in Germany and France - it's
not the price of a new sailplane which kills the activity.

--
Bert Willing

ASW20 "TW"


"Michel Talon" a écrit dans le message de
...
Bert Willing wrote:
Well, the airfoil of the Pégase is French, the rest is a copy of German
design...


Of course, the rest is not "unrelated" to the ASW20 that Centrair used
to build under German licence :-) But i maintain that the design of the
wing is extremely important for a glider, and that in the case of the
Pegase, this design was original, and a great success. Until appearance
of the Discus and its quite novel wing, the Pegase was in par with other
similar gliders. If you want me to say that the different German firms
have produced the most beautiful and fine gliders of our epoch, this is
obviously true. They have failed however to keep the prices reasonable,
and this is, in my opinion an extremely grave failure, which is killing
the sport.

--

Michel TALON

Bert Willing wrote:
Well, it's easy to say that German gliders are much more expensive than
French ones... Centrair didn't have to pay the development of the ASW20,
neither of the Pégase airframe,

Let us stick with the Pegase, since the ASW20F was an unmodified copy
of the ASW20, and the other Centrair productions are crap. The Pegase
had at least a new wing, hence needed all sorts of development and testing
expenses, new certification process, etc. When you take that into
account, and notably the certification process is said to be very
expensive, you see that your argument is far from being conclusive.

neither of the Alliance 34 (which, as SF34
was a complete flop in Germany, so I still don't see the reason that
Centrair took it up...).
Development cost of a glider makes for a significant part of the selling
price as you have to get the amortization from somewhere.
And sorry, if I look at the fleet of club ships in Germany and France - it's
not the price of a new sailplane which kills the activity.


Yes of course, it is. I know tons of people who have stopped flying
because it was too expensive, and even many more who dream of flying
but cannot afford. When something as simple as a glider, that is
something vastly simpler than a car, costs the price of a house,
something is utterly wrong. You can argue as much as you want about
research and development involved in this industry, i think it doesn't
explain squat about this failure. Completely inefficient production
processes is surely a more convincing explanation. This being said, it
is true that French and German clubs have considerable fleet, because
they have accumulated gliders for many years, and in particular, at
least in France, they have bought a lot of Pegase which were relatively
cheap. However they need to renew fleet, and regularly buy new models
to avoid erosion of their capital. And due to the insane actual prices,
this means they have to charge higher memberships or worse rent their
gliders higher. Sorry to say that, but my salary is strictly aligned on
the official inflation, that is to say, it stays fixed ... and i am not
alone in this situation, by far. Hence when glider prices double in a
few years, a lot of people get expelled out of the activity, and you
observe what i can see around me, glider clubs are becoming old people
clubs.



--

Michel TALON

something vastly simpler than a car, costs the price
of a house,

I think you are ignoring economies of scale. If the
Peugeot 306 had a total production run of only 500
over a period of several years as opposed to (at a
guess) 500 a day, then I think your little peugeot
runabout would probably cost about £1,000,000. Gliders
are handmade because that is the most cost effective
method of composite construction for a production run
that does not extend into the 10,000's. It is not highly
inefficient, it is the most efficient economical means
available. Do you not think that Schleicher and Schempp
would be using a cheaper means if it were available?
After all, the cheaper the glider is to make, the higher
their profit margins.

It is just a sad fact that gliders will always be expensive,
it is the nature of the market.

I don't see this price argument as valid. My salary hasn't gone up for a
long time neither... But of course, if you insist on always flying the very
last gimmick, or if you insist on buying 0h gliders, you will end up paying
a lot if you go for your private glider.
On the club side, I can tell you that many clubs in Germany have fees which
didn't even follow inflation over the last 20 years, and they were still
able to renew their fleet. French clubs have been a bit stuck with the
Pégase capital-wise: sure it's a lot of glider for little money, but the
value of a used Pégase goes down rapidly - whereas I had to pay about the
same amount of money for my ASW20 like the first owner who bought it 20
years ago (of course, that doesn't take into account inflation). One reason
for the Pégase going down in value is probably that the French market is
swamped by them, and that you can't sell them in Germany (where the market
is about 3 times larger).

As to inefficient production methods - building a couple of hundred gliders
from negative moulds is handcrafting, nothing else. If you want to have more
performant production tools, you need *much* higher numbers to be able to
compensate the tooling investment. The only way to reduce cost is either
cutting down on the finish (has been done successfully by Grob), or going to
do the production in countries with low wages (as done by SH and DG).
Still with the high prices for last generation gliders, companies like LS go
belly up...

--
Bert Willing

ASW20 "TW"


"Michel Talon" a écrit dans le message de
...
Bert Willing wrote:
Well, it's easy to say that German gliders are much more expensive than
French ones... Centrair didn't have to pay the development of the ASW20,
neither of the Pégase airframe,

Let us stick with the Pegase, since the ASW20F was an unmodified copy
of the ASW20, and the other Centrair productions are crap. The Pegase
had at least a new wing, hence needed all sorts of development and testing
expenses, new certification process, etc. When you take that into
account, and notably the certification process is said to be very
expensive, you see that your argument is far from being conclusive.

neither of the Alliance 34 (which, as SF34
was a complete flop in Germany, so I still don't see the reason that
Centrair took it up...).
Development cost of a glider makes for a significant part of the selling
price as you have to get the amortization from somewhere.
And sorry, if I look at the fleet of club ships in Germany and France -
it's
not the price of a new sailplane which kills the activity.


Yes of course, it is. I know tons of people who have stopped flying
because it was too expensive, and even many more who dream of flying
but cannot afford. When something as simple as a glider, that is
something vastly simpler than a car, costs the price of a house,
something is utterly wrong. You can argue as much as you want about
research and development involved in this industry, i think it doesn't
explain squat about this failure. Completely inefficient production
processes is surely a more convincing explanation. This being said, it
is true that French and German clubs have considerable fleet, because
they have accumulated gliders for many years, and in particular, at
least in France, they have bought a lot of Pegase which were relatively
cheap. However they need to renew fleet, and regularly buy new models
to avoid erosion of their capital. And due to the insane actual prices,
this means they have to charge higher memberships or worse rent their
gliders higher. Sorry to say that, but my salary is strictly aligned on
the official inflation, that is to say, it stays fixed ... and i am not
alone in this situation, by far. Hence when glider prices double in a
few years, a lot of people get expelled out of the activity, and you
observe what i can see around me, glider clubs are becoming old people
clubs.



--

Michel TALON

Bert Willing wrote:

As to inefficient production methods - building a couple of hundred gliders
from negative moulds is handcrafting, nothing else. If you want to have more
performant production tools, you need *much* higher numbers to be able to
compensate the tooling investment. The only way to reduce cost is either
cutting down on the finish (has been done successfully by Grob), or going to
do the production in countries with low wages (as done by SH and DG).
Still with the high prices for last generation gliders, companies like LS go
belly up...


Shure, and this is really a pity. Still i am convinced that it is
absolutely essential to cut radically on prices. After all, other
industries succeed perfectly in cutting prices by a factor of two
in a couple of years to survive in a competitive market. I see many
examples of industries where there is a constant effort
to augment productivity, diminish prices, etc. I am convinced that
the glider factories have never done this reflexion effort
and content themselves to augment their tarifs each year.
This destroys the sport, destroys their market, and will ultimately lead
to their disparition. Gliding is by nature a sport for young people,
not for rich people. You will have hard time recruiting guys who
are both rich, have a lot of free time, good reflexes, etc. At the
end of the day it remains only a crew of retirees to animate the clubs.



--

Michel TALON

I have always understood that the first ASW20F was an exact copy of the
Schleicher built machine, but built under licence by Centrair.

I also heard that the ASW20FL was not covered by the licence, but was an
unauthorised copy of the Schleicher ASW20L; and that it did not incorporate
certain modifications incorporated into the German machine; and that as a
result they are not strong enough and use of the tips is now forbidden.

It is obvious to anyone who looks at it that the fuselage and tail feathers
of the Pegase are pure ASW20. I also heard that the unflapped wing uses
the ASW20 wing main spar.

I like flying the Pegase, I had a share in one for a while. But then I
have always liked Schleicher gliders.

I don't recall that Centrair have produced any successful gliders which are
not essentially Schleicher.

I have owned several Peugeot cars, I have one now. Build quality has never
been their strong point, not after the 403 anyway.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Michel Talon" wrote in message
...


Bert Willing wrote:

Well, the airfoil of the Pégase is French, the rest is a copy of German
design...


Of course, the rest is not "unrelated" to the ASW20 that Centrair used
to build under German licence :-) But I maintain that the design of the
wing is extremely important for a glider, and that in the case of the
Pegase, this design was original, and a great success. Until appearance
of the Discus and its quite novel wing, the Pegase was in par with other
similar gliders. If you want me to say that the different German firms
have produced the most beautiful and fine gliders of our epoch, this is
obviously true. They have failed however to keep the prices reasonable,
and this is, in my opinion an extremely grave failure, which is killing
the sport.

Michel TALON

"Michel Talon" wrote in message
...
Bert Willing wrote:

As to inefficient production methods - building a couple of hundred
gliders
from negative moulds is handcrafting, nothing else. If you want to have
more
performant production tools, you need *much* higher numbers to be able
to
compensate the tooling investment. The only way to reduce cost is either
cutting down on the finish (has been done successfully by Grob), or
going to
do the production in countries with low wages (as done by SH and DG).
Still with the high prices for last generation gliders, companies like
LS go
belly up...


Shure, and this is really a pity. Still i am convinced that it is
absolutely essential to cut radically on prices. After all, other
industries succeed perfectly in cutting prices by a factor of two
in a couple of years to survive in a competitive market. I see many
examples of industries where there is a constant effort
to augment productivity, diminish prices, etc. I am convinced that
the glider factories have never done this reflexion effort
and content themselves to augment their tarifs each year.
This destroys the sport, destroys their market, and will ultimately lead
to their disparition. Gliding is by nature a sport for young people,
not for rich people. You will have hard time recruiting guys who
are both rich, have a lot of free time, good reflexes, etc. At the
end of the day it remains only a crew of retirees to animate the clubs.

Michel TALON


I agree Michel. There HAS to be a way to reduce production costs. There
are thousands of people that will tell you that "it can't be done". My
experience tells me that these are "negative experts" who always know
exactly, to the Nth decimal place, why whatever you want to do can't be
done, but are totally silent when asked how something CAN be done.

I tend to view the problem as an engineering one rather than an economic
one. Worse finishes by cheaper labor is not a rewarding way to go. I call
this a "negative compromise" where you end up paying a little less (or maybe
the same) for a much worse product.

So, how might it be done? Start with computers, materials and processes.
Large CNC milling machines can produce extremely accurate plugs or even
finished molds. If the process of making the flying part accurately
replicates these CNC generated mold surfaces, little post molding work
should be needed. The fact that a lot of post molding work IS needed today
says a lot about the materials and methods used.

A very promising area the homebuilders are playing with is "Vacuum assisted
resin Infusion" which reduces the labor of wet layup by 75%. Lay the dry
fiber in place on the mold and vacuum bag it. Then, inject resin at
strategic places so it flows through the whole part. The resin content
drops to around 25% instead of the 40 -50% typical of wet layup and voids
are almost completely eliminated. The result is a lighter, stronger, more
accurate and cheaper part.

It would be very economical if the resin saturated part could be heat cured
while in the mold. If the mold is fiberglass, it will warp with repeated
temperature cycles (PIC 20D). Making the mold out of aluminum is expensive,
but you only have to pay for it once. The payback is fast cycle times
because you can heat the part in the mold so it cures in minimum time. You
may get three parts per day instead of only one and the part will be far
more temperature tolerant.

There must be thousands of tricks like this that drive up quality while
cutting costs. That's the way to go. Think outside the box.

Bill Daniels

Bill Daniels wrote:

So, how might it be done? Start with computers, materials and processes.
Large CNC milling machines can produce extremely accurate plugs or even
finished molds. If the process of making the flying part accurately
replicates these CNC generated mold surfaces, little post molding work
should be needed. The fact that a lot of post molding work IS needed today
says a lot about the materials and methods used.

The German manufacturers are already doing this. Still, there are
joining lines that must be dealt with.

A very promising area the homebuilders are playing with is "Vacuum assisted
resin Infusion" which reduces the labor of wet layup by 75%. Lay the dry
fiber in place on the mold and vacuum bag it. Then, inject resin at
strategic places so it flows through the whole part. The resin content
drops to around 25% instead of the 40 -50% typical of wet layup and voids
are almost completely eliminated. The result is a lighter, stronger, more
accurate and cheaper part.

Another method, used in SparrowHawk production, is pre-impregnated
carbon fiber cloth and rovings. Resin content is precisely controlled,
the cloth easily cut, layup is dry.

It would be very economical if the resin saturated part could be heat cured
while in the mold.

The laid up SparrowHawk parts are cured in an oven to 225 deg F,
yielding a stronger material than wet layup, and it doesn't have to be
painted white, either. I don't know why the German factories don't use
this material.

If the mold is fiberglass, it will warp with repeated
temperature cycles (PIC 20D). Making the mold out of aluminum is expensive,
but you only have to pay for it once.

The SparrowHawk uses carbon fiber molds, but the major components (wing,
fuselage, tail surfaces) are _assembled_ in aluminum jigs, so the
accuracy of the molds are not critical. It's more expensive to set up
production, but you are assured of accurate parts.

The payback is fast cycle times
because you can heat the part in the mold so it cures in minimum time. You
may get three parts per day instead of only one and the part will be far
more temperature tolerant.

Ah, here's the rub: unless you are making more than one glider a day,
this has no value.


There must be thousands of tricks like this that drive up quality while
cutting costs. That's the way to go. Think outside the box.

After watching the SparrowHawk in various stages of completion, I can
tell there are far more pieces in a glider than you can imagine! Each
one has it own mold and must be laid up then cured, it must be glued or
bolted in by hand, then the halves of major components mated, glued, and
cured, canopy fitted, filling and painting, wiring and instruments
installed. It just goes on and on.

Also, the materials are expensive. The urethane paint on the SparrowHawk
varies from $160 to $400 a gallon, depending on the color, and it takes
more than a gallon. It's a small glider, too.

I'm sure improvements in glider manufacturing will continue, but I don't
see any thing dramatic coming along. To build a cheap glider now can be
done: make it small, make it light, and build 3 a week so the molds are
always busy and the factory space is all in use.

How cheap would this 11-12 meter, 35:1 glider have to be so they could
sell that many? Already, I can hear people saying "That is silly! for
only a little extra you make a 15 meter glider!" and "That is silly! for
the same price you can buy a used glider with more performance!".

I think we could build a good, cheap glider, but I don't think we could
sell it.

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

Eric Greenwell
Washington State
USA

Great thinking outside the box, but it shows that both of you have never
been involved in the economics of small and medium series production of
composite parts.

--
Bert Willing

ASW20 "TW"


"Bill Daniels" a écrit dans le message de
...

"Michel Talon" wrote in message
...
Bert Willing wrote:

As to inefficient production methods - building a couple of hundred
gliders
from negative moulds is handcrafting, nothing else. If you want to
have
more
performant production tools, you need *much* higher numbers to be able
to
compensate the tooling investment. The only way to reduce cost is
either
cutting down on the finish (has been done successfully by Grob), or
going to
do the production in countries with low wages (as done by SH and DG).
Still with the high prices for last generation gliders, companies like
LS go
belly up...


Shure, and this is really a pity. Still i am convinced that it is
absolutely essential to cut radically on prices. After all, other
industries succeed perfectly in cutting prices by a factor of two
in a couple of years to survive in a competitive market. I see many
examples of industries where there is a constant effort
to augment productivity, diminish prices, etc. I am convinced that
the glider factories have never done this reflexion effort
and content themselves to augment their tarifs each year.
This destroys the sport, destroys their market, and will ultimately lead
to their disparition. Gliding is by nature a sport for young people,
not for rich people. You will have hard time recruiting guys who
are both rich, have a lot of free time, good reflexes, etc. At the
end of the day it remains only a crew of retirees to animate the clubs.

Michel TALON


I agree Michel. There HAS to be a way to reduce production costs. There
are thousands of people that will tell you that "it can't be done". My
experience tells me that these are "negative experts" who always know
exactly, to the Nth decimal place, why whatever you want to do can't be
done, but are totally silent when asked how something CAN be done.

I tend to view the problem as an engineering one rather than an economic
one. Worse finishes by cheaper labor is not a rewarding way to go. I
call
this a "negative compromise" where you end up paying a little less (or
maybe
the same) for a much worse product.

So, how might it be done? Start with computers, materials and processes.
Large CNC milling machines can produce extremely accurate plugs or even
finished molds. If the process of making the flying part accurately
replicates these CNC generated mold surfaces, little post molding work
should be needed. The fact that a lot of post molding work IS needed
today
says a lot about the materials and methods used.

A very promising area the homebuilders are playing with is "Vacuum
assisted
resin Infusion" which reduces the labor of wet layup by 75%. Lay the dry
fiber in place on the mold and vacuum bag it. Then, inject resin at
strategic places so it flows through the whole part. The resin content
drops to around 25% instead of the 40 -50% typical of wet layup and voids
are almost completely eliminated. The result is a lighter, stronger, more
accurate and cheaper part.

It would be very economical if the resin saturated part could be heat
cured
while in the mold. If the mold is fiberglass, it will warp with repeated
temperature cycles (PIC 20D). Making the mold out of aluminum is
expensive,
but you only have to pay for it once. The payback is fast cycle times
because you can heat the part in the mold so it cures in minimum time.
You
may get three parts per day instead of only one and the part will be far
more temperature tolerant.

There must be thousands of tricks like this that drive up quality while
cutting costs. That's the way to go. Think outside the box.

Bill Daniels