SEN-483 October 6 2000
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News and Reports 2000 - second half
SCAT Electronic News 6 October 2000 issue 483
Table of contents
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F1B duration / P. King -007
A-1 encore - Thorklidsen
High Winds in Aussi Team Selection? - Bogie
Peter King ZIP Files
FAI HLG @ USIC - Stalick
Bunt bail out - Morgan
Team selection programs.. - Brokenspar
F1B duration / P. King
======================
Jean Wantzenriether (Sarrebourg, France)
Dear Peter,
Thank you very much to have given us the results of your F1B
simulations. It is a quasi impossible task! Therefore the
congratulations of much people are due. Perhaps I act as the
interpreter of all...
As you undoubtedly envisaged, comments will not miss. Here's mine. It
is based on experiment, in particular on flights carried out after a
simultaneous start, in calm air. They were models less sophisticated
than those today, but of international value. Let's admit two F1B of
different aspect ratio, 20 and 14. To obtain the same angle of climb,
the wak of 20 will fly at a velocity lower than a wak of 14. This is
visible to the naked eye. It will thus use a longer motor run. With
the same long run, the small wak will be underpriviledged. Therefore
if the large one of 20 climbs up to 96 meters, the small one of 14
will never reach the 93 meters which simulation proposes. The
theoretical question which arises here, is of a great interest : why
climbs a great aspect ratio at a lower speed ?
Let's suppose now that both competitors each have a run optimized for
their own style of flight. The small one of 14 must climb quickly,
say in 35 seconds, and it is able to climb higher than the large one
of 20, say 8 meters higher. Of course, the large one will keep the
final advantage in pure duration. On the one hand because of its
longer run. In addition because of its better glide. How to take
account of these
characteristics in a simulation?
I would like to know other facts of experiment, and other opinions...
Jean Wantzenriether (Sarrebourg, France)
A-1 encore
==========
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As I mentioned to both Martyn Cowley and Fred Terzian I am interested in the
original A-1 AMA rules. I believe the allowable area was a combination of
the wing and stab area and the special rules now in NFFS are a copy of ones
that Mike Thompson and Bob DeShields generated and they just list total wing
area only. I believe this is in conflict to the original rules and results
in a bigger model. As a side note I made a typo on the original input to
SCAT with the question since I knew the weight had changed may times and
would be quite different from the original AMA A-1 rules. I believe the
original rule was 5.08 oz. Does anyone have one of the old AMA rule books
that can clarify these questions?
Thanks again,
Terry Thorkildsen
High Winds in Aussi Team Selection?
===================================
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While reformatting the Australian Team Selection scores in SEN 482, I
noticed that the first six scores in F1A, first four in F1B, and the first
three in F1C were higher by 200 seconds. Must have been something the wind
added. Be sure Lindy looks out for this in the US Team Selection next week.
I have corrected the Aussi scores for the Luddite readership.
Bill Bogart
Peter King ZIP Files
====================
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PETER KING ZIP FILES
First let me thank BA dor his kind words about the simulations. Let me say
I owe a great deal to all those people who have contributed thoughts and even
data to help me get nearer to the truth of things. It will be a long time
before we have a complete and reliable simulation but I am narrowing down the
data, the more info I get from all of you.
I had a problem unzipping those files to so I will zip them again and hope
they work this time. My apologies
Peter King
AmCup
=====
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Roger,
Here's the lastest w/ the Hoosier Cup and Denver Dynasty Cup correction. JIM
[The excel sread sheet produced by the admirable Mr Parker had something
new that caused the macro produced bt the esteemed Mr Kaynes to barf.
In spite of it beging just software as the erudite Mr Morgan states below
I was not able to fix this befre going to Lost Hills for the revered Mr
Livotto's event]
FAI HLG @ USIC
==============
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Regarding the inclusion of FAI HLG at the USIC. The USIC events are reviewed
each year and continuously tinkered with. Typically, the issue of concern is
the availabilty of time and space at the site. I do not believe any added
problems are created by including FAI HLG, but I am not privy to a set of the
rules, and I am sure the CD is not either.
There is a meeting with AMA, to plan all ofthe Nats for 2000, which is
scheduled for October 21 at Muncie. Although it would be helpful to make the
contact with the CD prior to the meeting, we have until late December to
finalize all events.
The CD of the indoor nats this year will be Dave Thomson, who is not
connected by email. You may contact him to express your views on the subject
by writing a letter using paper, pen and stamp. His home address is: 5432
Haft Rd., Cincinnati, OH 45247-7422. His phone number is: 513-574-8322.
Bob Stalick, NFFS Prez.
Bunt bail out
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Hi Roger,
In regard to the discussion on RC DT.... I think all forms of bunt bail out,
DTing after a dud launch etc are not legal. My understanding is that Free
Flight is not controlled flight (whether the flight is controlled by the
competitor or a flight system) and that a rule has been introduced to
prevent controlled flight by computational systems. Having a flight system
that decides whether the model should bunt or not or whether the model
should DT to give another chance is no different to having a flight system
that decides whether the model should turn left or right to find a thermal -
such as in the joke article I very much enjoyed writing for FFDU last year
and which is attached in case you might like to print it. Make no mistake -
the hardware is all off the shelf - it just requires a bit of software
development.
Best regards,
Vin Morgan
[Vin, the rules do not prevent controlled flight by computational systems -
this would prevent the use of any micro controller based timer and some
form of mechanical timers too. What it does prohibit is closed loop
feed back systems such as one that might detect the stall point
and continually adjust the decalage.
Very clearly the ability for F1A the model to "decide" if it is still on
tow or if the sportsman has let the line go is a great boon to the
sportsman. The same as the ability to decide if it is on the line
and adjyust the glide rudder accordingling. In fact I assume that
moving rudder in a circle tow F1A is permitted , it is after all
a cloded loop system, is because the flight has not started until
the tow is 'finished'. The ability to detect the bunt failure is not
different from the ability of a F1B to detect that torque is low so the
prop should be stopped. Both of these detect a physical condition
and carry out an irreversible action.
In my, undoubtably humble opinion the way Stamov uses the
bunt timeout watchdog is borderline useful. There is plenty
of scope for screw up in 1) setting the time out period
incorrectly, 2) having the model come off the line when the
model is close to the ground and bunting into something hard,
3) forgetting to turn off the feature on the second attempt.
But it does have a big wow factor and gets the Luddites excited.
There is a very important balance between complexity and
practicality. Often our desire to have the super gadget
out weights common sense.
In my business we refer the bit of software development as just a SMOP
- a simple matter of programming. i.e. the most difficult part of
the project ]
Team selection programs..
=========================
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Mike Achterberg's discussion has a poignant note, "....they can wait two
years and try again."
Of course, this feature expires, finally.
I admire Jerry Fitch. And who does not !
The Team Selection Program takes your measure, every cycle.
Wish me luck ! As I do to you all.
Brokenspar
...........
Roger Morrell
