1. The definition of "horizontal & vertical."

[Peter G]

The 2009 issue of the F2 Sporting Code addresses the horizontal /
vertical issue as follows.

Quote: SC F2 09. page 23 Article 4.2.15.1. Terminology and wording
"Vertical" Means at right angles (perpendicular) to the ground over
which the flying takes place. This word is marked with inverted commas
(quotation marks) throughout this text to provide a constant reminder
that the requirement is for model aircraft to fly at right angles to
the ground, even if that ground has a perceptible slope.

"Horizontal" Means parallel to the ground over which the flying takes
place. This word is marked with inverted commas throughout this text
to provide a constant reminder that the requirement is for model
aircraft to fly parallel to the ground, even if that ground has a
perceptible slope. Unquote

Furthermore and in order to prevent practicability problems resulting
from „terrain following“ (or not...) flying the Code limits what a
perceptible slope may be:

Quote: SC F2 09. page 72 Article 6.5.2.1
Contest organisers shall provide a site with one or more Contest
Flight Circle/s that are horizontal within plus/minus 30 cm across the
entire diameter of each circle. .... Unquote

For the purpose of discussion please assume the above rules being
eliminated and answer/ discuss/suggest:

a.) How much slope is acceptable?
b.) At which height shall the two level laps after take-off be flown?
c.) At which height shall the two invertedl laps be flown?
d.) Over a sloped circle where is the height to be flown measured?
e.) At which height shall the manoeuvre bottoms be flown?

Peter Germann

[CMa...@t-online.de]

Bitte nicht verzweifeln, wenn ich mich nicht offiziell dazu äußere. Ich hoffe, wir sehen uns in Bodman. Dort möchte ich mich mal ganz ausführlich über diese Themen unterhalten.
gruß,   claus

-----Original-Nachricht-----
Betreff: 1. The definition of "horizontal & vertical."
Datum: Thu, 02 Jul 2009 11:09:23 +0200
Von: Peter G <peterd...@bluewin.ch>
An: F2B Group <f2b-...@googlegroups.com>

[Keith Renecle]

Hi All, I have written a short article on this subject. I hope that it is alright to include pictures. I did compress them so that the files size is small.

 

Vertical & Horizontal in the stunt rules

 

Most flying sites are not perfectly level, so this is a really valid discussion. The technical definition of vertical has already been defined perfectly well, so I believe that rather than make our own definitions to suit sloping flying sites, we should simply follow these terms as internationally accepted. There are just too many optical illusions around the majority of these sites to confuse the untrained eye to use the surface of the flying circle as the horizontal reference. Having said that, we then have to answer a few more questions. As Peter rightly asks:

 

a.) How much slope is acceptable?
b.) At which height shall the two level laps after take-off be flown?

c.) At which height shall the two inverted laps be flown?

d.) Over a sloped circle where is the height to be flown measured?
e.) At which height shall the manoeuvre bottoms be flown?

 

Before answering these questions, I would like you to consider the following example at the last world champs in Landres. If you look at the photo’s below, you can see that the slope is quite drastic.

 

 

 

 

 

The first picture shows Igor Burger getting ready to fly, and you can see the height of the marker. The 2^nd photo shows the model approaching the marker on the higher section of the site, and you can see the difference in this height. Photo 3 shows the model level with the lower slope marker where the model was launched, and please notice the crane in the background which has obviously been erected “vertically” as in the true definition. I added Photo 4 to show another vertical tower in the background.

 

I seem to remember that the markers were initially placed at equal heights above the ground level on the previous week-end for the world cup competition. Please correct me if I’m wrong with this assumption. I would presume that these markers were then aligned using a theodolite. The point is that because the pilots will obviously stand and rotate in true vertical fashion, they will tend to fly the models like a gyroscope. Pilots tend to make the least possible corrections to the level flight paths, because any noticeable deviation will lose valuable points. It is really hard to follow a path parallel to a sloping surface. I have made a point of watching this for many years now. At our club, for example, we have a reasonable slope that I believe is about 1,5 ft. (45 cm.) When our racing pilots practice with their fast racers, they always fly horizontally and do not follow the slope.

 

The biggest problem with stating that vertical is perpendicular to the particular slope, is that this angle will change all the way around the circle. The vertical manoeuvres like the vertical and overhead eights, hourglass, plus the exit of the clover, will all present serious problems for an actual vertical reference angle in this case. When pilots and judges look upwards to follow these manoeuvres, they lose any ground reference. To add to this, if the wind changes direction even 45 degrees, then this angle will change as well, and the higher the model flies, the greater this angle will appear. The standard method used through the years for judges, is to check the angle of the model and lines to see if they are indeed above the pilot’s head. I can only speak for myself, but I would presume that pilots’ tend to use their own body as a reference for the vertical pull-ups, and also to see if the tops of the vertical and overhead manoeuvres are indeed vertical.

 

O.K. now back to Peter’s questions:

 

a.)   How much slope is acceptable? - I would say that we need to get the slope of the grass circle in Landres, and use that as the maximum for international events. I would guess that the slope on that field must be at least 2 ft. (60 cm.) or greater. Sometimes it is a matter of compromise, and this is important to consider, because not all flying sites are indeed suitable to host a world championship event. The Landres site is notorious for being a “challenging” site for stunt events due to the violent turbulence from the nearby trees etc. We have to be extremely grateful however, to the French organizers for offering to host the world champs once again. We did manage to complete the stunt event successfully, even with such a slope. I would therefore suggest that on any sloping site, we should recommend the use of markers that have been aligned with a leveling instrument like a theodolite.

 

b.)   At which height shall the two level laps after take-off be flown? - The high side of the slope should be used as the reference point for the 1,5 metre above the ground height, and the theodolite would use this as the starting point to align the markers. Pilots would then fly up to this height in one lap. The worst case scenario is obviously the high side of the slope, because this would the lowest height above the surface.

 

c.)    At which height shall the two inverted laps be flown? – As above, this height can be easily observed. If there are no markers, you will find that good judges are able to see this anyway.

 

d.)   Over a sloped circle where is the height to be flown measured? – As per my answer in a.), use the high side of the slope as the reference height.

 

e.)   At which height shall the manoeuvre bottoms be flown? – The corrected marker height.

 

The main point to remember with this whole subject, is that it takes good training for judges to see the perspective all of the manoeuvre shapes. To make a sloping surface a reference point in the actual rules, just complicates the matter, especially for the vertical manoeuvres. To avoid this particular issue, I would suggest that we do not hold big competitions like the world champs at venues that are worse than Landres. If it is indeed necessary to use flying sites with a bad slope, then a local rule can always be issued to pilots and judges on the days of the competitions, or when they enter. As I said above, we managed reasonably well at Landres after the markers were aligned properly, so it can be done. I am pretty sure that if we measured the flying sites that we have used at most of the world champs, that none of them would be perfectly level, but the point is that if the slope is minimal then the effect is hardly noticeable anyway. 

 

 

Regards,

 

Keith R

 

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[Peter G]

Dear friends

In order to replace the „parallel to ground“ paradigm by one where
horizontal refers to the bottom level of the flight hemisphere, thus
allowing level flight over sloped terrain (perhaps along accordingly
erected markers?), the related terminology must be changed first.

For the purpose of efficient discussion, here is a suggestion how this
could be done. It refers to the current 2009 Sporting Code:
---------

Current SC F2 09. page 23 Article 4.2.15.1. Terminology and wording

"Vertical" Means at right angles (perpendicular) to the ground over
which the flying takes place. This word is marked with inverted commas
(quotation marks) throughout this text to provide a constant reminder
that the requirement is for model aircraft to fly at right angles to
the ground, even if that ground has a perceptible slope.

Replace by:
Vertical: Means right angles (perpendicular) to the horizontal base
of the flight hemisphere.

"Horizontal" Means parallel to the ground over which the flying takes
place. This word is marked with inverted commas throughout this text
to provide a constant reminder that the requirement is for model
aircraft to fly parallel to the ground, even if that ground has a
perceptible slope.

Replace by:
Horizontal: Means the base (equator) of the flight hemisphere. The
base lies horizontal at a height of 1.5 m +/- 30 cm above the highest
point of the ground under the flight circle. In manoeuvre descriptions
the base of the flight hemisphere is referred to as the baseline.

Add:
Flight hemisphere: Means a half globe shape whose bottom (equator)
plane lies horizontally above the ground.

Add:
Flight circle: Means a horizontal circle whose radius is equal to the
flight radius.

-----------

It is obvious, that a change as the above will make it neccessary to
adjust most of the manoeuvre descriptions and a couple of diagrams,
too. I will be glad to do so, but we need to find consensus on
definitions first.

Please comment soon and do not hesitate to suggest language
improvements, too.

Kind regards, Peter Germann

Keith Renecle wrote:
> Hi All, I have written a short article on this subject. I hope that it is alright to include pictures. I did compress them so that the files size is small.
>
>
>
> Vertical & Horizontal in the stunt rules
>
>
>
> Most flying sites are not perfectly level, so this is a really valid discussion. The technical definition of vertical has already been defined perfectly well, so I believe that rather than make our own definitions to suit sloping flying sites, we should simply follow these terms as internationally accepted. There are just too many optical illusions around the majority of these sites to confuse the untrained eye to use the surface of the flying circle as the horizontal reference. Having said that, we then have to answer a few more questions. As Peter rightly asks:
>
>
>
> a.) How much slope is acceptable?
> b.) At which height shall the two level laps after take-off be flown?
> c.) At which height shall the two inverted laps be flown?
> d.) Over a sloped circle where is the height to be flown measured?
> e.) At which height shall the manoeuvre bottoms be flown?
>
>
>
> Before answering these questions, I would like you to consider the following example at the last world champs in Landres. If you look at the photo's below, you can see that the slope is quite drastic.
>
>
>
>
>
>
>
>
>
>
>

> The first picture shows Igor Burger getting ready to fly, and you can see the height of the marker. The 2nd photo shows the model approaching the marker on the higher section of the site, and you can see the difference in this height. Photo 3 shows the model level with the lower slope marker where the model was launched, and please notice the crane in the background which has obviously been erected "vertically" as in the true definition. I added Photo 4 to show another vertical tower in the background.
>
>
>
> I seem to remember that the markers were initially placed at equal heights above the ground level on the previous week-end for the world cup competition. Please correct me if I'm wrong with this assumption. I would presume that these markers were then aligned using a theodolite. The point is that because the pilots will obviously stand and rotate in true vertical fashion, they will tend to fly the models like a gyroscope. Pilots tend to make the least possible corrections to the level flight paths, because any noticeable deviation will lose valuable points. It is really hard to follow a path parallel to a sloping surface. I have made a point of watching this for many years now. At our club, for example, we have a reasonable slope that I believe is about 1,5 ft. (45 cm.) When our racing pilots practice with their fast racers, they always fly horizontally and do not follow the slope.
>
>
>
> The biggest problem with stating that vertical is perpendicular to the particular slope, is that this angle will change all the way around the circle. The vertical manoeuvres like the vertical and overhead eights, hourglass, plus the exit of the clover, will all present serious problems for an actual vertical reference angle in this case. When pilots and judges look upwards to follow these manoeuvres, they lose any ground reference. To add to this, if the wind changes direction even 45 degrees, then this angle will change as well, and the higher the model flies, the greater this angle will appear. The standard method used through the years for judges, is to check the angle of the model and lines to see if they are indeed above the pilot's head. I can only speak for myself, but I would presume that pilots' tend to use their own body as a reference for the vertical pull-ups, and also to see if the tops of the vertical and overhead manoeuvres are indeed vertical.
>
>
>
> O.K. now back to Peter's questions:
>
>
>
> a.) How much slope is acceptable? - I would say that we need to get the slope of the grass circle in Landres, and use that as the maximum for international events. I would guess that the slope on that field must be at least 2 ft. (60 cm.) or greater. Sometimes it is a matter of compromise, and this is important to consider, because not all flying sites are indeed suitable to host a world championship event. The Landres site is notorious for being a "challenging" site for stunt events due to the violent turbulence from the nearby trees etc. We have to be extremely grateful however, to the French organizers for offering to host the world champs once again. We did manage to complete the stunt event successfully, even with such a slope. I would therefore suggest that on any sloping site, we should recommend the use of markers that have been aligned with a leveling instrument like a theodolite.
>
>
>
> b.) At which height shall the two level laps after take-off be flown? - The high side of the slope should be used as the reference point for the 1,5 metre above the ground height, and the theodolite would use this as the starting point to align the markers. Pilots would then fly up to this height in one lap. The worst case scenario is obviously the high side of the slope, because this would the lowest height above the surface.
>
>
>

> c.) At which height shall the two inverted laps be flown? - As above, this height can be easily observed. If there are no markers, you will find that good judges are able to see this anyway.
>
>
>
> d.) Over a sloped circle where is the height to be flown measured? - As per my answer in a.), use the high side of the slope as the reference height.
>
>
>
> e.) At which height shall the manoeuvre bottoms be flown? - The corrected marker height.

> ------------------------------------------------------------------------------

[Massimo Semoli]

Dear Peter and all,
At first, I think that the definition of "horizontal and vertical" should be
identifiable from the physic and scientific point of view.
No doubts or criticisms would be pointed out.
Therefore, I suggest to consider the direction of the gravitational force.
This is also congruent with the vertical force of the weight that acts on
the model when it is flying horizontal and on the pilot who stands up
vertically. This is independent from the slope of flying circle.

Here below the terms from Wikipedia:
HORIZONTAL
In astronomy, geography, geometry and related sciences and contexts, a plane
is said to be horizontal at a given point if it is locally perpendicular to
the gradient of the gravity field, i.e., with the direction of the
gravitational force (per unit mass) at that point.
VERTICAL
Vertical means up and down. An object is in a vertical position when it is
aligned in an "up-down" direction, roughly speaking perpendicular to the
horizon or horizontal plane.
In science, it can also refer to:
• Vertical direction, the direction aligned with the direction of the
force of gravity, as materialized with a plumb line

The text of the new rules could include the reference to the force of
gravity, taken from part of the wikipedia description.
For the judges the vertical direction can be seen from the pilot standing up
alignment as usually verified for checking the verticality of the "reverse
wing over". If necessary, with a plumb line, the vertical direction can be
verified whenever you need. The horizontal plane will be perpendicular to
the pilot standing up alignment. Trained judges can identify the real
horizontal and vertical plane of sloping flying circles.

Second, Peter's questions:

> a.) How much slope is acceptable?

I agree with Keith, the maximum slope of the flying circle should be 60 cm.
It is also the tolerance for the level flight. With sloping flight circles
the external marker are mandatory. They shall be leveled with a theodolite.

> b.) At which height shall the two level laps after take-off be flown?

It is extremely difficult for the pilot to follow the slope of a flying
circle. He should give corrections to the model continuously.
Therefore the flight shall be horizontal at 1.5m +/- 30cm height measured as
the lower height at the ends of the sloping flying circle. If the slope is
60cm the pilot could raise his arm of minimum 30cm (for keeping the lines
always horizontal)for staying in the level flight lower tolerance.
Fly horizontally is easier than follow a constant ground height.

> c.) At which height shall the two inverted laps be flown?

As above.

> d.) Over a sloped circle where is the height to be flown measured?

The high side of the slope shall be used for the reference height.

> e.) At which height shall the manoeuvre bottoms be flown?

Since the maneuvers can be 90 degree horizontally wide (e.g. square eights
with bottom flat side), the concepts above shall be applied. Maneuver
bottoms shall be at 1.5m +/- 30cm height measured as the lower height at the
ends of the sloping flying circle. The leveled markers can help to evaluate.

Exceptional specific considerations to the flying circle slope can be
applied by the organizers in agreement with the FAI jury. Acceptability,
markers, height, ecc, considering them as local rules. However, as many
times stressed, they cannot infringe the sporting code.

Best regards
Massimo Semoli


-----Messaggio originale-----
Da: f2b-...@googlegroups.com [mailto:f2b-...@googlegroups.com] Per conto
di Peter G
Inviato: mercoledì 8 luglio 2009 18.32
A: F2B Group
Oggetto: Re: 1. The definition of "horizontal & vertical."

[Peter G]

Thank you, Massimo. I am certain the Group welcomes and appreciates
your carefully laid out analysis.
May I invite the so far silent members of or Group to contribute by
commenting?
Thank you
Peter Germann, Coordinator

[Peter G]

Dear all

am I right, despite only few comments made so far, when I assume that
the Group supports changes aimed at the elimination of the "parallel-
to-ground" paradigm?

If so, we should first of all concentrate on Article 4.15.1. (page
22) Terminology and Wording and adjust it accordingly.

For the sake of this disscussion I have uploaded a sample draft
proposal on "files". It basically replaces parallel-to-ground with
flight along a baseline, along parallels (latitude) and along
meridians (longitude) on the surface of a hemisphere which is located
level 1.5 m above the highest point above the ground.

Please have a close look and share your comments.

rgds Peter Germann

[aage wiberg]

Dear all.

I believe there has been very good discussions in this group the last couple
of months despite many have been silent in the discussion, which is
regrettable.

With his 3 D graphics Keith has done a remarkable task of making the
geometrics become clear to anyone including the problem of pilots flying
soft corners despite of the rules calling for real sharp looking corners. We
have now the tools to teach judges what to look for. This is unique!

The big challenge is to keep focus on the very few "bricks" that is the
foundation of F2B. The 45 degree angle, the circular flight, the straight
paths, horizontal and vertical and last and mostly overseen - the tight
turns. All of these are the essence of true stunt, with the most difficult
thing being the tight corners, because they make it so difficult to keep the
shape right and make the straight paths still be good. Only the very best
pilots with huge amount of training, the best turning models, the best
fastest reactions abilities and nerves to keep flying tight whatever the
flying conditions are, come close to the perfect looking stunt pattern.
Those that fulfil all the demands best must be the winners. No more, no
less.

It is not enough to have 4 of the 5 columns right to become champion. Or
second - or third. Some of the pilots show breathtaking corners, but
certainly some of the fly off pilots do not. Judges must learn to watch for
sharp corners as one of the vital parts of judging. This must be emphasized
to all education of judges new as "old". The top pilots of competitions must
have all of these elements in their flights. All of us who fly know how hard
it is to make good looking patterns including sharp corners. The judges are
vital to make this come true. When ambitious pilots see it pays off to do it
right they alter their flying accordingly, and the sport level of F2B will
be improved. We must reach for the stars although we never will be able to
grasp them. This "philosophy" is the beauty of stunt and the judges have an
important role here.

Maybe stunt will look more "nervous" when pilots add all elements to their
flights. But as I have tried to spell it out. Stunt is no beauty contest. To
say it brutally we have too few crashes in today's competitions. Real
stuntmen have had most of their bones broken throughout their career. So
must it also be in stunt - that is if you want to be ranked between the best
pilots. Luckily we can save our bones and only count our broken models in
competition. Only the "dare devils" deserve the medals! But until now they
seem to only come in a little after "the nice flying guys"! This must be
altered! We have a unique opportunity to make a big leap forward for our
sport right now with Keith's work in order to improve judging.

The message must be spread out, and judges must learn to be observant to all
the "bricks" in the stunt pattern. Only when all the requirements are met as
much as it can be done, stunt becomes a real sport. "Hobby pilots" must
accept to be ranked lower.


To the horizontal vertical thing I agree with Massimo's thoughts.


To the rest of you guys in this group who have been mostly silent. Please
express your standings in this important matter.

Greetings to all of you!

Aage Wiberg.


-----Oprindelig meddelelse-----
Fra: f2b-...@googlegroups.com [mailto:f2b-...@googlegroups.com] På vegne
af Peter G
Sendt: 13. juli 2009 14:35
Til: F2B Group
Emne: Re: R: 1. The definition of "horizontal & vertical."

[Claus]

. . ." we have too few crashes in today's competitions" . . .
Has anyone ever heard a more silly babble?!
I refuse to comment on such unbelievable nonsense!
Claus Maikis

[aage wiberg]

Maybe Claus needs a little more explanation.

When you fly real sharp corners, you must keep the model on a straight
course longer to have the corner sharp enough. This means that there is such
a short fraction of a second to give rudder, that sometimes things
inevitably must go wrong. Furthermore it is much more difficult to leave the
turn in right direction horizontally as the turn must stop abruptly. As
there is only 1,2 meter from success to disaster at speeds exceeding 100
km.h. there is a real risk of hitting the ground at the turns. This does not
happen when we start our sharp turns far too early, make a softer turn,
which makes it much easier to come out of the turn at right minimum height
and on a stable straight horizontally course. When hitting the ground does
happen so relatively few times, the reason is clearly because most pilots
fly far too soft corners. I included.
I fly Kerkko Kehravuo's *96 model which I have used for some years now.
Kerkko was also a pilot who flew real sharp corners. And he had his Impact
model trimmed so that it flew sharper corners than most do or can. I had to
remove a 24 grams lead plate inside the rudder in order to be able to
control the model. So flying gets more difficult when you aim at meeting the
requirements for sharp corners. And still have the ability to fly straight
and make loopings circular.

I hope I make myself understandable by this explaination.

Claus certainly must remember a pilot as Luciano Compostella from Italy. He
flew breathtaking sharp corners, and I saw him crash a model in '96. Try to
remember. Yuriy Yatsenko from Ukraine did the same at Landres in 08. They
are both good examples of pilots that try to meet the challenge of hard
corners more than most pilots dare or can. And this costs sometimes.

Greetings

Aage.

-----Oprindelig meddelelse-----
Fra: f2b-...@googlegroups.com [mailto:f2b-...@googlegroups.com] På vegne

af Claus
Sendt: 14. juli 2009 01:39

Til: F2B Group
Emne: Re: R: 1. The definition of "horizontal & vertical."

[Keith Renecle]

Hi all,

Thanks Aage for your inputs again. Maybe Claus took your analogy of crashing
a little bit too literal? I have just had an in-depth off-forum discussion
with Ken Dowel and some others, and I can see that my reasons for starting
this discussion are not very clear. I tend to take the "long way around" to
explain most things, so let me try again..... All that I am trying to
achieve is to add shapes to my judges training program that relate back to
what we see in reality. This should be exactly the same as the rules, and it
is "almost" true. We just need to polish up some final small issues. This
will not have any immediate effect on the way that pilot's are flying right
now, but will make a difference to the way that we train judges. In the
future when pilots finally start to trust that they will be judged on strict
adherence to the rules, then we will start to see just how well our top
pilots can fly to these exact shapes.

I am not concerned about the exact degrees of any of the manoeuvre shapes,
when I state that our rules must be geometrically correct. We certainly do
not need to split hairs at all. For example, it is like our present
description of the triangles. It's width is defined as "slightly wider" than
the 45 degree arc of the loops and squares. This is good enough. We don't
need to know that it is actually 50,325 degrees or anything like that. The
shape is defined as a triangle with equal length straight sides and the top
at the 45 degree elevation angle. This top in fact has a tolerance of plus
minus 30 cm. This is close enough for our application. The big issue for
judges here is that they need to be able to see the difference between this
45 degree "height" and a 60 degree height. Most triangles are scored better
right now if they are that big and have soft corners. There other big
difference is the way the spherical "straight lines" and curves will look
for the judges viewpoint.

My call for the tops of squares to be defined as a straight line, is because
the pilots are already flying this path that way, and the shape that is now
in the rules does not show what to expect. Sure the top line may look
slightly like a downward curve if flown as a great circle, but in reality it
is done so quickly that it looks pretty straight. The top can therefore
still be defined as being at 45 degrees plus/minus 30 cm. each way. If I
plot this exactly as the description then it looks like the square in my
present CL Sim. This is not even close to the shape that the pilots fly, or
indeed are capable of flying. I have plenty of traced video footage of most
of the world's best pilots to back up what I am saying here.

You must remember that we are all demanding of our judges that they see the
tiny differences between the all of us "hot-shots" and especially when it
comes to the really good pilots in the finals. The standard of flying is so
good these days that judges need extra training so that their ability to see
and score these tiny differences can be sharpened. I have volunteered to
create this type of interactive program and I have been working on this for
many years already. If anyone feels that they have a better method to do
this then let me know, and I can get back to building and flying. I have
received mails lately, and also been told to my face, that if I keep on
trying to implement my ideas then they will give up flying F2B. Ladies and
gents, it is not my personal idea's that I am trying to push. Not at all. I
just need to show trainee judges shapes that they can expect to see in real
life. That's all. I simply take each rule step and trace it onto the surface
of a sphere, so there is nothing mystical about this, and they are certainly
not my own personal idea's.

We have now in just these few weeks cleared up the issue of vertical and
horizontal, so let's all push on, and clarify the basic issue of the
squares, and then we can look at the problems in the clover a little more
objectively as well. I fully understand that my training system will only
make a small difference, but maybe it is this "small difference" that we
need right now??

--------------------------------------------------------------------------------

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[Igor]

Hi All,

We are actually preparing for Beograd, so please excuse us not
reacting too much. However I see I must jump in with my personal note.

Keith did great tool not only for judges but also for pilots. I saw
many times the perfect flight of the perfect model in his sim. Just to
see what I have to feel when I fly well – the feeling of well done
shapes. But I must say that I never feel or see any >>>breathtaking<<<
things. I also never come to any danger positions with my model. If I
fly I fly first of all safely.

It is everything true. We have to fly tight corners, this is not
beauty contest and models sometimes crash. But does not matter, I do
not like to see any crashes, I want to see beauty models, flying safe
and beauty pattern and this all under the all rules. Tight does not
mean ugly and does not mean danger (and I am the last who has problem
to make bottoms in knee high altitude). Well – some of us are building
our models.

This is not stunt in meaning “broken bones” this is precision
aerobatic, so we should take care for balanced and repeated precision,
we must balance our flight to fulfill all rules as well as possible,
not to show broken models to public. If someone comes to see crashes,
we have combat circle. I personally expect beauty and well flying
models.

Tight corner is better that open, but square loop is not defined as a
loop with 1.5m corners. We have also shapes, intersections, sizes,
straight segments (at least this is about straight segments :-) ) … so
calling for wining those flying tight has some merit, but I feel from
those words from Aaage strong overlooking of all other attributes.

I also feel it little bit incorrect to state that actual world
champion (we know who) fly open corners and Yuriy Yatsenko (now I do
the same incorrect thing when I name them) fly tighter and thus he had
to place better. I saw to fly both. And I can say I saw also several
errors, but I am not able correctly say who and how had to place …
just by my eyes. We have tabulation, marks scores and 6 judges. It is
very easy to say judges did it wrong, but this forum is here to find
out how we can improve it.

Until we do not say exactly who and what radius did and who and what
other errors did together with them, we cannot simply say that other
had to win, it is little bit dehonesting all of that effort around …

igor
.

[Peter G]

Baseline Definition

In an off-forum exchange Massimo Semoli has convinced me to suggest
the following definition of the baseline:

Baseline: Means the base great circle (equator) of the flight
hemisphere. The base lies parallel to the horizontal plane at right
angle to the direction aligned with the direction of the force of
gravity and at a height of 1.5 m +/- 30 cm above the highest point of

the ground under the flight circle. In manoeuvre descriptions the base
of the flight hemisphere is referred to as the baseline.

----------

[aage wiberg]

Hi All.

Denmark had a humorist a few generations back, who was a genius to pinpoint
foolishness in human behaviour and speech. His name was Robert Storm
Petersen, called "Storm P." In one of his more than 10.000 drawings with a
text below it we see a professor type like Albert Einstein on a bad hair
day. He is standing at a rostrum, the glasses are on his forehead and he
talks to his audience. The text says like following:

- "Originally language was developed by man to create understanding between
people. Nowadays, however, it seems that language seems to create
misunderstandings between people."-

This was drawn and written in late 1920ies or early 30ies. I seem to have
been trapped in this dilemma with my writing of crashes.

Please, my friends - do not take my words too literately.

What I tried to emphasize was that tight corners is one of about 5 main
demands that the F2B rules ask of us. The 4 demands are well fulfilled by
many pilots. That is size of figures, vertical/horizontal, straight paths,
and circular path of loopings. The 5.demand for tight corners is so
important as it influences so much on some of the other demands such as the
precise vertical/horizontal, and the straight paths, because it is much more
difficult to come out of a tighter corner right than if the corner is more
open. The model needs to be light weight, it must be trimmed unstable enough
to perform what I call "breathtaking" sharp corners, and still be able to
meet the other requirements. And the pilots must be "aces" to do so.

I risk to use another metaphor. The demand for tight corners is so
important as it is to a big part here that the rams are separated from the
sheep.

It is the same thing in Formula 1 racing. When reaching the tight corners of
the race track, the driver who keeps the throttle on for a fraction of a
second longer than the others, will be of better chance of winning. Like in
F2B, the driver is balancing on a knife's edge - another metaphor - He is
also in a risk of loosing the track and take a spin into the gravel, and
thus lose his chance of winning. This happens regularly in F1 and when we
fly close to the rule in the tight corners, we have the same situation.
When the pilot keeps the throttle on that little longer, that is keeping
the vertical downwards path longer, it leaves less room and time to perform
the turn and greatly increases the risk of a crash. The tight corners also
makes it much more difficult to continue in a steady horizontal path after
the turn. That is why it is so important.

The fact that there are so few hits of the ground indicates that too many
fly loose corners and thus have less risk of rubbing the canopy and rudder
in a slide down the asphalt. And it is also an indication showing that it
has become a habit for judges to accept open corners too much or maybe
always has been so. Therefore it is important to have extra focus on this
thing. I do not overlook the other aspects of F2B rules as some have
indicated.

And I do not think Yuriy was best in Landres. He was not the only pilot with
tighter corners. Some of them were also in fly off. His brother for instance
was one of them, but I just used Yuriy's touch down on the asphalt after a
too low tight corner to illustrate my point.

And it is known that David you know who is capable of performing more tight
corners than he did. I have been told he clearly can do so. The sad thing is
that it pays off to go the easy way not doing your best in the corners to
make the rest come out better, and thus become champion. The soft corner
thing is so important as it influences other parts of the flight. It is not
at all easy, but the judges must not give the pilots this opportunity to "go
the easy way round". David can do tighter corners than he did in Landres. We
must do our best in the corners, also in bad weather. It may not look so
pretty in Landres and other places when the turbulence makes flying extra
difficult.
We should not be in the circle to give the audience a good looking safe
flight.
We shall do our best to fulfil the requirements.
And one of them is tight corners.



In F2A, F2C and F2D it is less complicated as we have the stop watches to do
the work + the cuts in F2D. They deal with facts that are easier to
determine.

In F2B we have to deal with the human mind's perception of evaluating the
flight. Therefore it is important to have focus of this.

A few centuries ago people could loose their heads or be burned alive to say
that our planet is round and the horizon curves.
Old habits and perceptions are not easy to change. But we must keep trying.
We only risk to loose face - or a model. Which is worse?

Here in this forum we have the opportunity to be part of altering things to
the better. Let us use this opportunity cleverly.

And let me finish with a quotation from another (in Denmark - at least)
world famous writer, thinker and inventor, Piet Hein. He made, among much
other things, small rimes with philosophical content.

It was written during the cold war period and referred to the people sitting
with the buttons to start nuclear disaster.

It goes like:

The noble art of loosing face
may some day save the human race.

Greetings to all of you.

Aage.

-----Oprindelig meddelelse-----
Fra: f2b-...@googlegroups.com [mailto:f2b-...@googlegroups.com] På vegne

af Igor
Sendt: 14. juli 2009 13:57
Til: F2B Group
Emne: Re: R: 1. The definition of "horizontal & vertical."