ASH 31Mi

On Dec 20, 7:32*pm, JS wrote:
* With the inner panels having a 14m span it would be possible to
build 15m tips for the 31 and fly three classes.
It would be faster than the AS-W17 with wooden 15m tips, and that was
a rocket ship in it's time!
Basics of the KS review of the AS-W17/15m was: "Two speeds, thermal
and red line."
Jim

On Dec 20, 3:56 am, Dieter Reuter wrote

Hi Jim,
interesting idea to get a new 15m wing for the 26 or 31. But with such
a high minimum wing load, this makes not really sense for me. The
empty weight of the ASH-31Mi will increase to 400-420kg, some of the
first ASH-26E reaches 390-400kg.
Maybe if a lot of customers ask Schleicher to build 15m tips. I'll try
to ask Martin Heide if this could be a future option, next time when I
pick up my 29 in a few weeks.

Dieter

"John Galloway" wrote in message
...
The thing that caught my eye is this sentence:

"Our newly-developed wing structure allows for a wing span of 21m despite
of a wing section as thin as 13%."

Anyone got any information about what is new about the wing structure?
Anything that might make the surfaces have a low susceptibility to
shrinkage and deformity?

John Galloway

John,

My ASH26E is six years old with no sign of wing deformity (spar showing
etc). I understand this was a problem for Schleicher at one point, and some
ordering new ships were insisting that wings be cured twice etc.

I sometimes fly winter wave and have no gel coat cracks to show for it at
all. My glider is most always left assembled and hangared.

bumper
zz
Minden

On Dec 20, 9:47*am, "bumper" wrote:
I understand this was a problem for Schleicher at one point, and some
ordering new ships were insisting that wings be cured twice etc.

What curing is done at Schleicher? I did not think they had or used
an autoclave. I think my 28 was cured in Arizona.

Andy

Bumper,

How often do you fly with water ballast?

I have seen several Schleicher wings in Arizona and New Mexico that
had visible wing spar bumps (when viewed from the right angle),
gliders less than 5 years young.

The flight and maintenance manuals for my ASG29 are emphatic about
completely emptying the wings after flights with water ballast. They
even added additional drain plugs at the wing root rib leading edge,
to ensure complete drainage when trailered, and the manuals go so far
as to suggest removing the wing root gaskets when ballast will not be
used for a while.

So, the factory seems to be firmly convinced that residual moisture is
the shrinkage culprit. I am going to take their word for it, and keep
those wings ventilated on the ground.

2NO

On Dec 22, 7:06*am, Tuno wrote:
Bumper,

How often do you fly with water ballast?

I have seen several Schleicher wings in Arizona and New Mexico that
had visible wing spar bumps (when viewed from the right angle),
gliders less than 5 years young.

The flight and maintenance manuals for my ASG29 are emphatic about
completely emptying the wings after flights with water ballast. They
even added additional drain plugs at the wing root rib leading edge,
to ensure complete drainage when trailered, and the manuals go so far
as to suggest removing the wing root gaskets when ballast will not be
used for a while.

So, the factory seems to be firmly convinced that residual moisture is
the shrinkage culprit. I am going to take their word for it, and keep
those wings ventilated on the ground.

2NO

Ted

As already mentioned, the ASH-26E has water bags not wing tanks.

And because of wing loading, some ASH-26E do not see much water,
especially if they have the optional wing fuel bags. Whether Bumper's
26E has water bags and they are used much, he will need to answer.

Darryl

On Dec 22, 8:06*am, Tuno wrote:

So, the factory seems to be firmly convinced that residual moisture is
the shrinkage culprit.

Either that, or a very convenient way to blame the customer for the
problem. Personally I don't buy it. The humidity inside a wing in
some US states and many European countries is probably far higher for
a sailplane that has never been loaded with ballast than for one in
Arizona that has been loaded, dumped, and stored with the fill caps
off.

I got water inside the wings of my 28 when I landed out and got dumped
on by a torrential thunderstorm. The winds were high enough I secured
the airbrakes full open. Water filled the airbrake boxes and then
made its way into the wing. I tried very hard to drain in out, I
tried to vacuum it out with long tubes, but nothing worked. I could
still hear it sloshing around in there. I called the US agent
thinking the next step would be to drill holes in the wings, and he
said don't worry about it. I had pulled off the aileron push rod
seals to vent the wing aft of the spar and left them off for a few
days. After cooking in the trailer in the Arizona sun for a week or
less there was no more sloshing. All the water had gone.


Andy

"Tuno" wrote in message
...
Bumper,

How often do you fly with water ballast?



As Darryl says, many 26E's don't have water, especially if they have fuel
bladders in the wings, as mine does. To get heavy, I add fuel.

To minimize my carbon footprint, I've installed igniters for when I need to
dump ballast.

bumper
zz
Minden

At 15:52 19 December 2008, Andy wrote:
On Dec 19, 6:14=A0am, wrote:
http://www.alexander-schleicher.de/p...h31_main_e.htm

I have revised my Christmas list!

Interesting that they are going back to water bags.

Also interesting that they claim no need for a tail tank. They said
the same for the 28 but then offered it as an option. I ordered one
with mine and I use it. Did anyone actually buy a 28 without the tail
tank?

Andy


Schleicher seem to have an interesting slant on this. I have a 27 without
a fin tank. Although ballast does move the cofg forward they say this is
no bad thing as you want to be nose heavy for running ridges and on good
days and tail heavy for weak thermals. Therefore, they argue that you put
water in for good days moving the cofg slightly forward, and drop it when
thermals are weak moving cofg further aft.

They see no need for pilot adjustment of balance through a fin tank. Some
owners obviously disagree as they pay extra for the tank.

I just add / remove tail lead as I feel for the day / season / type of
flying (within limits of course)

Jim

On Dec 19, 9:45*am, Jim White wrote:
At 15:52 19 December 2008, Andy wrote:
. Although ballast does move the cofg forward they say this is
no bad thing as you want to be nose heavy for running ridges and on good
days and tail heavy for weak thermals. Therefore, they argue that you put
water in for good days moving the cofg slightly forward, and drop it when
thermals are weak moving cofg further aft.

I agree with that. My ballasted CG is forward of my unballasted CG
despite the use of the tail tank. I only need about 1.5l to put
ballasted CG where I want it so maybe I don't really need it. My
unballasted CG is set for weak conditions and I had to add nose
ballast at a no water ballast contest as I got very tired of pushing
the stick when running between strong thermals.

Andy

That is the idea.
This was the first flapped airfoil on a 15 meter class glider of that
design to shift the C of P forward at high cruise. I can go as far forward
as 28% chord in the normal operating range. It was the insistence of G.
Waibel that one could carry laminar flow over 90% chord at the bottom
surface over a sealed hinge. The rest was up to L. Boermans to figure out.
Variation of that airfoil design are in used on all kinds of modern
gliders now. The side benefit is, that the normal H stab down load is
reduced or even contributing to the over all lift, when cruising faster.
The DU89-134/14 in its zero line configuration (#2 flap setting in an
ASW27) looks more like an airfoil for a tail less glider.

When you fly with out water you fly with the C of G back ( weaker
conditions) when adding water
(stronger condition) the C of G moves forward, this matches the design
outcome, hence, I personally think ,that lead to the idea of no tail tank
required initially.

As to stick force i.e. trim load on the stick and how they exactly relate
with water I do not know. I fly with no water till now because I fly
mostly in weak condition. I have my C of G back in the 80% range and with
that I have normal trim loads, Trim all the way back no stick load in a
steady 40 deg. bank and I can cruise with out stick load with trim
forward.
Udo

Schleicher seem to have an interesting slant on this. I have a 27
without
a fin tank. Although ballast does move the cofg forward they say this is
no bad thing as you want to be nose heavy for running ridges and on good
days and tail heavy for weak thermals. Therefore, they argue that you
put
water in for good days moving the cofg slightly forward, and drop it
when
thermals are weak moving cofg further aft.

They see no need for pilot adjustment of balance through a fin tank.
Some
owners obviously disagree as they pay extra for the tank.

I just add / remove tail lead as I feel for the day / season / type of
flying (within limits of course)

Jim