Searching for JSW Final Glide Calculator

[Mike Burgess]

Hi Newsgroup members.

This is my first posting, and probably immediately identifies me as a
soaring pilot living in the past - especially in these high-tech days of GPS
and flight computers.

However, most of my flying is still completed in wood or (at least) other
non-plastic machines.

I am in need of a JSW calculator for (ideally) an SF27b. Not too many of
these Scheibe Falkes around - for those unfamiliar with the type, in
performance terms it equates to Ka6E or Pirat. It is 'standard' class / 15M
span and with excellent handling (especially w.r.t. thermal scratching and
its good roll rate). Best glide is in order of 34:1 at 45kts (assuming I
have washed the wings and sealed the root joints).

Does anyone out there know if the JSWs are still made and, if so, is there
one which will suit my SF27 ? Where from / how much ?

Would welcome any advice (even offer of second hand - all you people now
upgraded to Peschges VP7, please search your aircraft's odds & sods pocket).
Supposed to be entering a comp weekend after next (10/11 July), so a little
desperate.

Failing search for JSW (or equivalent), does anyone have access to a polar
curve for the SF27b (missing from documentation I have).

mike.b...@virgin.net (East Sussex Gliding Club, UK)

[da...@theguests.prestel.co.uk]

Try RD Aviation near Oxford - 01865-841441

David

[Bob Gibbons]

As an alternative, you might consider putting together your own
circular calculator. I wrote a program that generated the required
overlays for a Stucker-type circular calculator. This is the type of
calculator that is a transparent overlay that goes over a map of the
local flying area. Knowing your polar you generate speed to fly
numbers that go into the program. The program generates the overlay
that lets you assembly the calculator. Simple to use, look down at the
map and see where you are, estimate the winds speed to fly and read
the required height off the overlay. At OSTIV 1991 I presented a
description of the theory behind the nomogram and a program, written in
Basic, to generate the overlay. Most computers still have a
rudimentary Basic compiler.

Download the paper and program from,

http://acro.harvard.edu/SOARING/ssa_programs.html

program name is ostiv91.zip

Bob

[rlovi...@transystems.com]

Tim Mara at Wings and Wheels in upstate New York sells them for
$24.95. Check out his website at www.wingsandwheels.com and look at
page 43.

Ray Lovinggood
Carrboro, North Carolina

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.

[Moshe Braner]

Bob Gibbons (r...@tartarus.rsc.raytheon.com) wrote:
: As an alternative, you might consider putting together your own

: circular calculator. I wrote a program that generated the required
: overlays for a Stucker-type circular calculator. This is the type of
: calculator that is a transparent overlay that goes over a map of the
: local flying area. Knowing your polar you generate speed to fly
: numbers that go into the program. The program generates the overlay
: that lets you assembly the calculator. Simple to use, look down at the
: map and see where you are, estimate the winds speed to fly and read
: the required height off the overlay. At OSTIV 1991 I presented a
: description of the theory behind the nomogram and a program, written in
: Basic, to generate the overlay. Most computers still have a
: rudimentary Basic compiler.

: Download the paper and program from,

: http://acro.harvard.edu/SOARING/ssa_programs.html

: program name is ostiv91.zip

Alternatively, I wrote a program in C (compiled into an
MS-DOS executable) that accepts 4 numbers defining the polar
and outputs a Postscript file that, when printed, is the
curves for the Stocker calculator. I then xerox it onto
a transparency.

If you have the book XC Soaring by Reichmann, this is the
calculator described near the end of the book. In the old
days people had the patience to plot those curves out by hand,
that is tedious...

- Moshe

[Sarah Anderson]

Sounds Wonderful Moshe, have you posted it anywhere... can we see the C?
Thanks, Sarah

Moshe Braner wrote:
...

[Michael Deleo]

Moshe,

If you send me the source code for your C program, I'll rewrite it in
Java. We could then put it on a website for anyone to use.

Moshe Braner wrote:
>
> Bob Gibbons (r...@tartarus.rsc.raytheon.com) wrote:
> : As an alternative, you might consider putting together your own
> : circular calculator. I wrote a program that generated the required
> : overlays for a Stucker-type circular calculator. This is the type of
> : calculator that is a transparent overlay that goes over a map of the
> : local flying area. Knowing your polar you generate speed to fly
> : numbers that go into the program. The program generates the overlay
> : that lets you assembly the calculator. Simple to use, look down at the
> : map and see where you are, estimate the winds speed to fly and read
> : the required height off the overlay. At OSTIV 1991 I presented a
> : description of the theory behind the nomogram and a program, written in
> : Basic, to generate the overlay. Most computers still have a
> : rudimentary Basic compiler.
>
> : Download the paper and program from,
>
> : http://acro.harvard.edu/SOARING/ssa_programs.html
>
> : program name is ostiv91.zip
>

> Alternatively, I wrote a program in C (compiled into an
> MS-DOS executable) that accepts 4 numbers defining the polar
> and outputs a Postscript file that, when printed, is the
> curves for the Stocker calculator. I then xerox it onto
> a transparency.
>

> If you have the book XC Soaring by Reichmann, this is the
> calculator described near the end of the book. In the old
> days people had the patience to plot those curves out by hand,
> that is tedious...
>
> - Moshe

--
_________________________________________________

Michael Deleo - Market Development Engineering
Sun Microsystems Computer Company
650 786-4084 (voice) 650 786-9555 (fax)

[Moshe Braner]

I got several requests for further info on my software for the
plotting of the Stocker final-glide calculator. I havn't yet
decided how to make it available and usable. Meanwhile, if
you send me the following 4 numbers describing your glider,
I can send you back the output of the program (for free, but
this is not a completed calculator):
best-glide ratio, best glide speed, some higher speed (typical
cruise speed), and the polar sink rate at that speed. Also
say whether you prefer knots or mph for the STF markings.

I've posted an article about how the calculator is constructed
and used, at http://www.uvm.edu/~mbraner/stockdoc.zip
- that is a ZIP-ed MS Word document, 6 pages of text,
and the drawings are not included in this 11K file.

--
Moshe Braner
47 McGee Road, Essex Junction, VT 05452 USA
(802) 879-0876

[Nigel L. Rotherham]

Moshe Braner wrote:

> I got several requests for further info on my software for the <snip>

Hello from a cool, sunny (well it will be tomorrow!) South Africa :)

Very good description of using the calculator but a pity no diagrams / pictures
included with the text.... However, just wanted to add that back in 91' a R. C.
Gibbons published a BASIC program for printing a Stucker glide calculator that
seems to do the job 100% The program has all the capabilities of setting polars
and most other parameters but does require BASIC to run. Qbasic seems to be ok
as would GW or any other 'flavour'. Can't remember where I d/l from but if
anyone interested I will send a copy of what I have to them as an attachment.
All you need to do is drop me a line at nig...@netline.co.za requesting a
copy. Think there is also a PS file that goes with it but not sure if I still
have a copy, maybe by the time someone (anyone?) makes contact I will have
recovered it from my archive tape....

Fly safe and remember, KEEP SMILING:-)

All the best from Nigel R

SZD-8 (Jaskolka)
--
Nigel L. Rotherham
P.O. Box 13407
Northmead
BENONI
1511
Gauteng
South Africa