Theory

[John Cochrane[_2_]]

I posted a new article on the theory of course deviations.

http://faculty.chicagobooth.edu/john.cochrane/soaring/index.asp#maccready

or directly

http://faculty.chicagobooth.edu/john.cochrane/soaring/docs/deviations_I.pdf

(If the links don't work google john cochrane soaring and you'll find
it under MacCready theory)

I'll try to get some magazine to publish it. Comments and improvements
welcome in the meantime. Yes, the daydreaming about soaring at the
office season has begun

John Cochrane
BB

[John Godfrey (QT)[_2_]]

On Sep 30, 6:19*pm, John Cochrane >
wrote:
> I posted a new article on the theory of course deviations.
>
> http://faculty.chicagobooth.edu/john.cochrane/soaring/index.asp#maccr...
>
> or directly
>
> http://faculty.chicagobooth.edu/john.cochrane/soaring/docs/deviations...
>
> (If the links don't work google john cochrane soaring and you'll find
> it under MacCready theory)
>
> I'll try to get some magazine to publish it. Comments and improvements
> welcome in the meantime. Yes, the daydreaming about soaring at the
> office season has begun
>
> John Cochrane
> BB

Well done!

[Jim White[_3_]]

At 22:19 30 September 2011, John Cochrane wrote:
>I posted a new article on the theory of course deviations.
>
>http://faculty.chicagobooth.edu/john.cochrane/soaring/index.asp#maccready
>
>or directly
>
>http://faculty.chicagobooth.edu/john.cochrane/soaring/docs/deviations_I.pdf
>
>(If the links don't work google john cochrane soaring and you'll find
>it under MacCready theory)
>
>I'll try to get some magazine to publish it. Comments and improvements
>welcome in the meantime. Yes, the daydreaming about soaring at the
>office season has begun
>
>John Cochrane
>BB
>
Brilliant! I knew I was doing it all wrong.
Jim

[Helge Zembold]

;786210']On Sep 30, 6:19*pm, John Cochrane
wrote:
I'll try to get some magazine to publish it. Comments and improvements welcome in the meantime. Yes, the daydreaming about soaring at the office season has begun

John Cochrane
BB


Hi John, you have the text, I have the magazine, now also in English :-)

Helge

[Gary Osoba[_3_]]

On Sep 30, 3:19*pm, John Cochrane >
wrote:
> I posted a new article on the theory of course deviations.
>
> http://faculty.chicagobooth.edu/john.cochrane/soaring/index.asp#maccr...
>
> or directly
>
> http://faculty.chicagobooth.edu/john.cochrane/soaring/docs/deviations...
>
> (If the links don't work google john cochrane soaring and you'll find
> it under MacCready theory)
>
> I'll try to get some magazine to publish it. Comments and improvements
> welcome in the meantime. Yes, the daydreaming about soaring at the
> office season has begun
>
> John Cochrane
> BB

Hello John:

I am sure that you will have no difficulty finding ready publication
for the paper, which in my opinion is the most important one you have
written in this genre. I did a similar analysis several years back to
quantify the key relationships. Some of this was shared in lectures
given at SSA Conventions and EAS (formerly SHA) gatherings in the late
90's and early 2000's. Themes & phrases such as "When Slower is
Faster" and "The Shortest 'Distance' Between Two Points is
Convoluted"- not implying curved space/time and speaking
metaphorically about "distance", of course. :-)

Whereas MacCready theory as normally applied matches cruising speeds
for straight glides in response to variable air masses, the approaches
your paper explores introduce what is often a more useful variable-
that of the varied course line. The other grand regime for piloting
strategy in a discontinuous atmosphere is dynamic maneuvering. This
places the focus on when, how quickly, how frequently and in what
manner to make changes from one cruising speed or another and one
heading to another, optimized to harvest energy or minimize it's
losses. This strategy, for example, could allow for counterintuitive
results when applied to Graph 1 of your paper with Pilot B arriving at
his destination much more quickly than Pilot A when dynamic
maneuvering is properly applied. This assumes that both pilots had a
*reason* to make deviations where they did, according to your paper's
impetus.

As usual, you have written in a clear, concise, and cogent manner.
Again, I think this is the most important and useful paper on soaring
strategies that you have addressed and wish to thank you for taking to
time to do it and sharing it as you have. Bravo, John!

Best Regards,

Gary Osoba

[JJ Sinclair[_2_]]

I like the Dale Bush rule which states, "follow the Cu's, unless they
are way off course.....................then follow them anyway". Many
times I have followed this rule and the reward was worth the risk.
Cheers,
JJ
PS, Winter soaring isn't officially open until someone askes, "what's
the best wax to use".

[Bob Kuykendall]

On Oct 1, 6:29*am, JJ Sinclair > wrote:
> I like the Dale Bush rule which states, "follow the Cu's, unless they
> are way off course.....................then follow them anyway".

Near the end of Sunship Game, there's that scene where Wally drives
the ASW12 straight across the blue hole, and George takes his Cirrus
along the cu around the edge. George later observed, "I thought it
would be faster the long way around," and of course he was right.

[Scott Alexander[_2_]]

John,

That was an awesome, awesome article. Thanks for taking the time to
write that. I can't wait to get back in the air soon to try out some
new ideas you wrote about.

Scott Alexander

[November Bravo]

On Sep 30, 6:19*pm, John Cochrane >
wrote:
> I posted a new article on the theory of course deviations.
>
> http://faculty.chicagobooth.edu/john.cochrane/soaring/index.asp#maccr...
>
> or directly
>
> http://faculty.chicagobooth.edu/john.cochrane/soaring/docs/deviations...
>
> (If the links don't work google john cochrane soaring and you'll find
> it under MacCready theory)
>
> I'll try to get some magazine to publish it. Comments and improvements
> welcome in the meantime. Yes, the daydreaming about soaring at the
> office season has begun
>
> John Cochrane
> BB

Hats off to a most excellent work, Professor!

The math and charts explain the concepts very well while sitting in
the living room chair but I abandon them when I fly and tend to react
a bit more intuitively, being a creature of habit as much as being a
creature of reason. So, to develop good habits based on your
analyses, are there "rehearsals" or "repetitive exercises" that pilots
could take advantage of with a soaring simulator such as Condor?
Engineering the soaring simulator for a series of such exercises,
allowing the computer pilot to "retake the test", much like a student
does when taking a multiple choice question on an exam, would really
be fun and allow the principles, analyzed in your paper to become more
intuitive. It would be interesting if such "exercises" could be added
to the popular soaring simulators, much like examinations are given to
students during their progression in their studies.

Again, John, thank you for enlightening us. It was a joy to read!

John Iacobucci

[Tony[_5_]]

Very much enjoyed the article John.

I was surfing the online Soaring archive and came across another
article that seems to address the same question. I haven't had a
chance to read through it very thoroughly but SSA members or others
with piles of Soaring Magazines laying around the house might check
out the April 1981 edition. Article named "Course Deviations During
Cross-Country Soaring" on Page 34.