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Old February 11th 13, 05:56 PM posted to rec.aviation.soaring
Richard Brisbourne[_2_]
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Posts: 23
Default Pirker Final Glide Theory

The Stocker calculator as described by Reichmann
(with instructions on how to make one) was
substantially more complex.

From memory you had a transparent disc with
altitude spirals in one hemisphere and in the other
hemisphere one set of curves corresponding to wind
components and an intersecting set of curves
corresponding to McReady readings. The latter set of
curves depended on the polar of the glider.

This disc was mounted on a map with the centre at
the goal point and it could be rotated about that point.
Above the disc was a linear cursor, also transparent
marked with distances, rotated about the disc centre.

To read the calculator, you rotated the disc so that
the spiral corresponding to your altitude lay over your
current position on the map. You then rotated the
cursor so that the line also lay over that point; the
other end of the cursor intersected the wind and
McReady spirals; the correct setting for the wind
could then be read off.



At 16:06 11 February 2013, pcool wrote:
I remember I had implemente the Stocker final

glide circles time ago in the

software, basically they represent glide ratio

ranges.

Since these concept are just obvious nowadays, I

assume that years ago -
before gps - everything had to be done using

approximated distances and
airspeed only, so the final glide was relative to the

airmass, in
principle,
and not to the ground.
Apart from that, if I am not wrong the Pirker

analysis does not consider
the
wind in final glide according to the document I read.
Nor does it consider total energy, apparently.

paolo


"Richard Brisbourne" wrote in message
...

Isn't this the principle behind the Stocker final glide
calculator, as described in Reichmann's
"Streckensegelflug", mid 1970s?


At 10:40 11 February 2013, pcool wrote:
In short, the Pirker "theory" says that in a final

glide
to the determine
the best speed you do:
1) calculate the glide ratio needed to get over the

final turnpoint
2) for that glide ratio you calculate the

corrispondent MC value for your
polar
3) for that MC value you get the speed to fly

I did not know pirker wrote these things in 1999,

for
me they are just
obvious.

paolo


"Paul Remde" wrote in message

...

Hi,

I think we'd all love to have access to the

document. I'd be glad to post
it on my web site if that would help.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.
________________________

wrote in message
news:4b8c77f1-1a6e-489e-a98c-

...

On Monday, January 14, 2013 10:19:27 AM UTC-5,

wrote:
Does anyone have a link to, or a copy of, an

English language paper or
explanation about Dr Herbert Pirker's final glide

theory? I can't even
locate one in German via Google.



I can find snippets about it relating to

implementation on StrePla in
2006vand I understand that a couple of the

NavBoxes on LX 8000/9000
relate
to this.




http://www.strepla.de/StrePla4/english/News/News_

in
_pocket_Winter05.htm



Thanks,



John Galloway


John: I've been looking through my stacks and

finally found an english
translation as well as the artilcle from aerokurier.

I'll get around to
scanning in PDF formats and email these articles

to
you.