Wild Bill tells it like it is

For PAMPA members another benefit. Steve and/or Larry has posted a good Wild Bill article - "Control-Line Aerodynamics Made Painless" that is highly recommended reading. The nomographs have been somewhat supplanted by LINEII, but you should read it in any case.

I sure hope more of these can be posted soon. Worth reading, for sure.

Brett

http://www.control-line.org/DesktopDefault.aspx?tabid=33

>For PAMPA members another benefit. Steve and/or Larry has
>posted a good Wild Bill article - "Control-Line Aerodynamics
>Made Painless" that is highly recommended reading. The
>nomographs have been somewhat supplanted by LINEII, but you
>should read it in any case.
>
> I sure hope more of these can be posted soon. Worth
>reading, for sure.
>
>Brett
>
>
>http://www.control-line.org/DesktopDefault.aspx?tabid=33

For what it's worth, I also consider this article must reading for anyone truly interested in how these things work and how to make them work their best. It's one of the first articles I ever "xeroxed" way back when and is still something I reread every year or two. It might seem like tough weeding the first couple of times but go back to it periodically as you gain insight into the things that are there and more will start to make sense every time you do it.

It might not be the "Bible", but it's about as close as we've come to a stunt religious artifact. Thanks to Steve for providing a great resource. (to say nothing of doing the same to Wild Bill for writing it in the first place.)

ooops.

OK Brett, I give up. Once you go to your link how do you get to the article????

Ted.... you need to login first.

>Ted.... you need to login first.

That sucks.

Join PAMPA.

Steven Yampolsky

Took a bit to log in, but I made it.

LAST EDITED ON Oct-13-04 AT 01:21 PM (CDT)
 
>Join PAMPA.
>
>Steven Yampolsky

I have. I think I even registered once. I cannot remember my login!

I sent an email to the webmaster. I relly want to see that article.

>Ted.... you need to login first.
Hmmm, I thought that happened automatically. Oh, well, I'll try again.

In the days before the web, and pre PAMPA, I would grab onto anything even quasi-techical related to CL. And Wild Bill's articles were extremely helpful.

Re the line angle nomograph...you should see all of the marks and notations I have made on the original mag article. I can't count how many times I have used it. Currell

I scanned the article from a copy of a copy so the graphs did not come out well. If anyone can figure out a way to get better looking graphs, it would make it 10 times better!!!! We have enough rokeet scientists here to figure this one out!

Steven Yampolsky

>I scanned the article from a copy of a copy so the graphs
>did not come out well. If anyone can figure out a way to get
>better looking graphs, it would make it 10 times better!!!!
>We have enough rokeet scientists here to figure this one
>out!
>

Yes - download the program based on the later version of the same analysis, and use that instead. I'm not sure that the nomographs are based on the latest/last version of the Soule line drag analysis and experiments. Bill could tell us, I'm sure.

But even the first paragraph rings so true, even almost 40 years later, that you ought to print it out and post it above your workbench:

Since the beginning of control-line models, back in the 40’s, the design phase, viewed from published information, has
been a “black art” relying on phases of the moon, superstition, etc. “Designers” appeared to ignore, or misunderstand, the
unique effects of flying in circles tied to a pilot in the center.
We were told to balance the model on front lead-out; or balance it on the bellcrank pivot; or to balance one thumb-print
forward of the main spar, or any other such nonsense that popped into a designer’s head. All we really knew was that his
model balanced there and he liked it! Always they were half right and half wrong.
Actually, we lived by the “Flea Fright” practice of adjusting each ship to tailor out the kinks, if it survived the first flight!
Ultimately, we were subjected to a lot of marginal designs (mine, too) flown by talented pilots who took it upon
themselves to explain phenomena they didn’t understand. Luckily, we do not wipe out pilots during crashes.

The data for the nomographs was a compilation of Pete's work, several other math folks who verified the procedure, my nomographs, followed by quite a number of flying tests by the Valley Circle Burners. They helped verify that the constants used were in the ballpark, always a criterion before publishing hardened numbers. The lines rake, and its affect on the trim and velocity of racing equipment is quite solid. Over time, I developed more data to give us a better idea how to BIAS the lines rake of a stunt ship to hang out there under most conditions of altitude and attitude. The stuff all came together much later, and hasn't been published, because I wrote the computer programs in arcane software, that isn't transferable today.

Luckily, there is enough anecdotal information that it takes very few iterations to find a good leadout point.

Best Regards
Bill

> The
>stuff all came together much later, and hasn't been
>published, because I wrote the computer programs in arcane
>software, that isn't transferable today.

I might be willing to take a stab at porting it to some other language, if you would be interested. I'm better at arcane languages than I am at any of them new-fangled modern "mystery scripts".

>Luckily, there is enough anecdotal information that it takes
>very few iterations to find a good leadout point.

I have to say - if I take Soule's program, put in the parameters, and calculate the line sweep for "zero whip", that's pretty much the right place for the leadouts to go, if nothing else is crooked. Within 1/4" for sure, and if it looks like it wants to be elsewhere, I figure there's some other problem.

Bill,

I would love to translate those programs. I speak "Arcane" pretty well and used to design parsers and compilers for some pretty obscure languages (Jovial, ASM360, etc.).

If you can email them to me at [email protected] I would be happy to help.

I owe you a few - you were the guy who inspired a lot of us snot-nosed kids in Tulsa oh so many years ago.

Ron King

Ron,

I swear this is the first time I've heard about jovial in 35 years or so. What was it, Jules Own Version of Integrated Algorithmic Language, or something like that? I learned that language in the mid 60's and used it on second-generation CDC computers. Remember the 1604. I think Cray designed that one too.

Where, when and how come you used it?

Tight lines,

>Ron,
>
>I swear this is the first time I've heard about jovial in 35
>years or so. What was it, Jules Own Version of Integrated
>Algorithmic Language, or something like that? I learned
>that language in the mid 60's and used it on
>second-generation CDC computers.

JOVIAL? I can write JOVIAL in my sleep - it's the language for the MILSTAR spacecraft flight software, of which I wrote a significant fraction.

Small world.

You guys are too much. I'll bet if we checked, we would find all sorts of interesting vocations within our CLPA group.

I worked on a Jovial parser to help Lockheed Martin translate some USAF Ground Control source code into C and C++. The vehicles are still in the sky and are still working. That's about all I can say.

Indeed, it is a very small world.

Ron King

I won't say what I did before retiring, but I wore a black hat, and my tools were a flashlight, mirrow, various red,blue and black pens and grease pencils and lastly a clip board.

Bigiron

When you speak of JOVIAL all I think of is Mike Pratt!!!!

>When you speak of JOVIAL all I think of is Mike Pratt!!!!
>

10-4 on the jovial Prattsky comment!
Ya gotta love him.

Mike G

You probably played hopscotch in those B-36 wings too!

LAST EDITED ON Jan-20-05 AT 04:27 PM (CST)
 
>I swear this is the first time I've heard about jovial in 35
>years or so. What was it, Jules Own Version of Integrated
>Algorithmic Language, or something like that? I learned
>that language in the mid 60's and used it on
>second-generation CDC computers. Remember the 1604. I
>think Cray designed that one too.

It occurs to me that you guys are officially Old Farts.

Semour Cray, one of the founders of CDC, is credited with the 1604.
See http://www.cbi.umn.edu/exhibits/cray/ and http://www.cbi.umn.edu/exhibits/cray/cray1604.html

Jules Own Version of the International Algebraic Language
Jules was/is Jules Schwartz.
Developed about 1959, for SACCS, a sort of successor to SAGE.
Supposed to have been replaced by Ada, but Ada never really replaced anything.
There's a nice retrospective by Schwartz in the History of Programming
Languages, edited by Wexelblat.

WOW, Talk about opening flood gates! Let me hasten to provide the rest of the information about my computer programs, since my calling it "arcane language" didn't scare anyone.

Right now, the programs that run my numbers for a PA airplane are written in EXCEL 97, with a reach back into LOTUS 123 for some curve fitting regression activity, and TK SOLVER 4. The instructions for both programs indicate they can be integrated, but I have not tried. (I upgraded to EXCEL 2003, but it doesn't reach back to the regression I needed).

The second, and not so minor, problem is, I've never completed constructing text instructions on their input/output (IO) procedures. I do have several text items that start to do that, but they dribbled off too early.

I am taking your interest seriously, and will think about my desire to finish some of this work. <Something for you all to consider.> The data constants I use for flap performance are a combination of data in the Airplane Aerodynamics book by Dommasch, Sherby and Connolly, and some off-the-wall adjustments of my own. They are very specific that these data are ESTIMATES, and we need to go to the wind tunnel for accurate data. HOWEVER, I've been using them a long time, and checking back to actual flight data, with minimal instrumentation. The stuff, DOES appear to detect BAD control setups, and to predict fairly accurate maneuvers in the sky.

This instant is sort of where I was back when I asked if the SN readers wanted to pay for analysis, and got the message (NOPE).

So, let's see if the efforts, mine and someone willing to integrate the math programs, will be worth while.

Best Regards
Bill:)

>WOW, Talk about opening flood gates! Let me hasten to
>provide the rest of the information about my computer
>programs, since my calling it "arcane language" didn't scare
>anyone.

Hard to imagine the use of "arcane" scaring off any CL people