Definition of horizontal, changes suggested

[Peter G]

Dear Friends

as the ongoing discussion of the horizontal/vertical issue has not
generated further comments so far, I have consoldidated the matter by
working out 4 related rule change draft proposals which I will forward
to you by separate e-mail later today. Please feel free to comment
here on Google.In order to address the Subcommitee in the name of our
Grpoup, I do need your comment, approval or disapproval. Should you
agree with the content of all four proposals, please say so by
replying on Google with „approved“ before July 31st 2009.

Further proceedings will be:

The Final form of the proposals shall be made (by me) by August 2nd.
On August 3rd, I will submit the proposals to the F2 Subcommittee as a
formal recommendation of the F2B Working Group, asking for the S/C to
submit the documents in the name of the Subcommitee before November
15th i.e. in time for to be brought forward to the 2010 CIAM Plenary
Meeting as S/C proposals. Projected date of setting in force is Jan.
1st 2011.

Kind regards, Peter Germann

[Peter G]

Here is a copy of Stefan Kraszewski's resonse of today

Quote:
I fully agree with your proposals related to the definition of
horizontal - vertical. As a judge F2B I know good enough, how many
problems causes actual rules this concerning. I remember my
competition in Vilnius in 1972. The slope of circle was about one
meter... I stroke the ground with wheels leveling-off the triangle
loops.
Endd of quote

[Paul]

As I stated in a previous post, I believe the level horizontal flight
should be relative to the center of the circle, ignoring any "issues"
with the levelness of the field.

[Peter G]

The measurement of the Landres site is on its way. I will report
findings asap, in order to resume the "horizontal" discussion.

> > Kind regards,  Peter Germann- Hide quoted text -
>
> - Show quoted text -

[Ken D]

While this particular subject is "on hold for the moment" there is,
unfortunately, a follow-on aspect to this re-defining of "level
flight" to being the "base" of our flight hemisphere. On its own,
something needs to be done in this regard, but it doesn't stop there.

Visualise a flying circle with a 1 metre slope across it's diameter.
When we set our hemisphere to the pilot's position in the centre (as
noted by Paul Walker) rather than 1.5 metres above the highest point
(which would be wrong), this then means that level flight height is
only 1 metre above the ground on the uphill side, and 2 metres on the
downhill side. That is fine for level and inverted flight manoeuvres,
but what happens with all other manoeuvres which have their bottoms
presently 1.5 metres above ground?

When the prevailing wind is from low to high sides, should the
"bottom" of the manoeuvre be re-defined to that 1 metre? - and
likewise 2 metres on the low side when the wind is high to low? What
happens when the prevailing wind is across this sloping surface? Will
we have a problem with the bottoms of horizontal eights with this
ground slope from side to side? Can we continue with a global bottoms
height that effectively ignores the variable distance between the
ground and our new "base"?

Perhaps we need to itemise this "base" as applying only to level and
inverted flight heights, and leave manoeuvres as they are. Otherwise,
in the event of a non-horizontal ground surface, it will be impossible
to maintain a constant dimension, especially if the wind is variable
in direction. That then becomes a nightmare for pilots and judges
alike.

Is this search for "exact" creating more problems than are being
solved?

[Keith Renecle]

Hi Ken and all,

It is not a search to be "exact," at all. It is in fact how the pilots
naturally fly on a sloped surface. The whole idea of trying to sort this
out, comes from defining vertical as perpendicular to the ground even when
the ground has a perceptible slope. This causes all sorts of problems of
trying to establish where the tops of the vertical manoeuvres are. Vertical
and horizontal should not require defining in our rules, but it is a fact
that some venues that are used for international competitions will continue
to be used. We therefore need certain guidelines in the rules to make sure
that we all know what the correct procedure should be. I believe that this
should be based on "common sense" and all we really have to do is to observe
what the pilots are naturally doing, and "reverse engineer" the rules from
there.

This last world champs was a really good example to observe because the
World Cup competition was flown the week-end before, with markers that were
set at a fixed height above the ground. These were then moved and set up
with
a theodolite and set with the lowest point on the high side of the circle. I
watched many flights and also flew plenty of times myself. Everyone flew the
natural level, and I did not see any ground following myself. I even looked
for this during the World Cup, and did not see any. I do not know who
initiated the move, but it was a sensible thing to do.

We are still waiting for JPP to measure the slope on the grass circle at
Landres, but I'm pretty sure that it is not as much as 1 metre. I would
guess from the photo's and video
that it's about 2 foot maximum. I don't believe that we need to get stuck on
the level flight aspect of these proposed changes. The base is simply a
horizontal level and not referenced to the ground if it is sloped. If we
need the height to be referenced from the centre of the circle, then
this is fine, and it will make the pull-outs on the high side more
compatible with Yuri Yatsenko's pull-outs, but only if the slope is severe.
I don't believe that we should be having international competitions on
circles with a slope of 1 metre. I will be surprised if JPP measures that
much in Landres.

When you say:

>"Perhaps we need to itemise this "base" as applying only to level and
> inverted flight heights, and leave manoeuvres as they are. Otherwise,
> in the event of a non-horizontal ground surface, it will be impossible
> to maintain a constant dimension, especially if the wind is variable
> in direction. That then becomes a nightmare for pilots and judges
> alike."

I'm not sure why flying level to a base line could be a problem. If you
consider leaving the manoeuvres as they are, as you've suggested, then you
need to consider a square eight being performed with the extreme right
vertical leg being at the low side (or the high side) of the circle. This
leg would be vertical, and as you go around left, the centre leg and extreme
left legs would all be at different angles. This is a nightmare.......not
performing to a real horizontal baseline.

Keith R

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18:19:00

[aage wiberg]

Dear all.

Maybe Landres can be a catalyser for the future demands for flying sites for
world championships.

How big a problem would it be for the French, if they knew beforehand that
there were some minimum demands for the circles to be used for the world's
most important competition for our sport?

It is really no big deal to remove the grass layer and fill up to prepare
the circle for a world championship. If that was done in the spring of 2009
this problem would have been solved at Landres.

I am a little tired of being mocked of by members of this group for
suggesting things that ought to be a matter of course.

It is obvious, that a flying circle for a world championship must be level
or so close to level that it does not cause problems for the competitors and
judges. Is this too much to ask for to the organizers of a world
championship approved by FAI? I think not!

Would it not be the right time now to set up some minimum requirements for
the flying sites? I also here think of the tall trees just some ten metres
from the circle producing turbulence that would have closed any airstrip for
real aircraft if you scale the turbulence up to 1 to 1. In Landres it might
be necessary to move the grass circle if it is not possible to remove the
trees, for instance because of neighbour resistance. It is not a good thing
to have the two circles separated too much, so that we become separated into
two groups, when we fly. But what counts mostly?

In some way I feel these discussions can be seen in a way that there are
camps with different agendas and that we have problems understanding each
others because we have different views upon what we are really doing here..
Do we want F2B world championships to be a social meeting for hobby people,
or do we want F2B to be a sport?
I feel that the answer I received from Claus Maikis when I put focus on the
issue of tight corners was below what is fair in this group of what is
supposed to be "experts".

If we really shall have a mission here to improve for the future we must be
ready to show which direction we shall move to really do some good for this
ballgame. And we should not, - like we say in Denmark, - walk as the cat
around the pot of hot porridge.

Actually I feel a bit that we are in a similar situation as those that began
claiming the world is round, and please - understand this right here. Then
all the conservative folks on the hill were determined that the world is
flat and has sharp corners.

We are moving forward. Now all agree (almost all, at least) that the world
is round.
Could we agree that the circle is round and should be flat - and the corners
of F2B sharp?

I really hope, ladies and gentlemen, that I speak here in a language that
you understand. English is not my native tongue, but in my heart I believe
we owe this effort to those who work so hard to "reach for the stars" as I
have written earlier in this forum.

Let me finish this time with a quotation from one who is recognized as a
wise guy worldwide: Soren Kierkegaard, a weird hard thinker from the 19.th
century. It goes like:

"To dare is to loose one's footing for a moment. Not to dare - is to loose
one self".

Greetings to all of you.

Aage.


-----Oprindelig meddelelse-----
Fra: f2b-...@googlegroups.com [mailto:f2b-...@googlegroups.com] På vegne
af Keith Renecle
Sendt: 13. august 2009 19:25
Til: f2b-...@googlegroups.com
Emne: Re: Definition of horizontal, changes suggested

[Keith Renecle]

Thank you Aage,
I can only agree with your statements of basic things that should be correct
at world championships. Flying sites should be as level as possible for
international competitions. We are trying to define things in our rules that
are already defined and understood in the technical world for centuries.
Vertical and horizontal should not be different in our application, because
it just causes confusion..........like we see now. Our manoeuvre shapes are
simple, basic shapes that are made up from straight lines and curves. I have
spent years now explaining these basic principles in workshops, the
internet, e-mail, Stunt News etc. etc. etc. I have used 2-D and 3-D
drawings, even animations, and yet I still have to debate this issue ad
nauseum.

Folks, we must remember that the F2B rules do not have to explain the
simplest details to anyone without any knowledge or experience in the sport.
The rules have to be simple, to the point, and technically correct. For
example, here is the definition of "straight line."

Straight Line: A great circle path, or part thereof. The shortest distance
between any two points on the surface of a sphere.

There you have it. Dead easy, and if anyone has a problem in understanding
this, it is not the fault of the FAI F2B rules, and can be explained by any
experienced person in the sport. All of our manoeuvre shapes are just shapes
on a ball, and have nothing at all to do with how we view them. Sure they
can look different depending on how we view them, BUT, the basic shape does
not change geometrically. Once again, it is not the duty of the F2B rules to
explain spherical geometry, but it IS necessary for our rules to be in
agreement with these principles.

We do not need to re-invent the wheel!

Regards,

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

[Ken D]

I'm real sorry, Keith, but your statement "All of our manoeuvre shapes

are just shapes on a ball, and have nothing at all to do with how we

view them." is not quite the case for our purposes. The Rules are for
the pilot to execute, therefore have EVERYTHING to do with how these
shapes are "SEEN" as opposed to what they may actually be. There's no
value is maintaining that a great circle path at any place other than
the base of our flying hemisphere is a straight line when it cannot be
seen in the same manner as we see level flight. Why? - Because we
cannot change our view away from the one and only hemispherical
surface we fly on. I am not saying that other great circle paths do
not exist on our hemisphere, but we cannot SEE them as great circle
paths or portions thereof, and what we SEE is what is most important
for both our flying Rules and our Judging observations.

Yes, you and I have discussed all this at length. The 45 degree
Meridian Line, as the tops of our square manoeuvres, will not be
"seen" as a straight line, when viewed from the base of the
hemisphere. Neither will the base of another hemisphere, your
preferred straight line, when that new hemisphere is positioned up for
the top of a square loop, because it is "drawn" (for want of a better
word) on our existing hemisphere. The other side of this new
hemisphere is comfortably out of sight 45 degrees below our flying
hemisphere behind the pilot's back. Please do not continue telling me
that this is a "straight line" relative to our vision of the flying
surface. It isn't, and cannot ever be.

When making our Rules comply with spherical geometry requirements, we
are moving into territory that serves no purpose other than even more
complexity and even more points of disagreement. The terminology of
"Equator" and "Meridian" serve just as well, perhaps even better for
simplicity, than any amount of Great Circles and parts of great
circles, etc etc etc.

Your efforts may well be admirable, but might you be too insistent on
making our Rules conform to those aspects of spherical geometry which
don't in fact have any material bearing on a) how we fly the Pattern;
b) how we see it for the purpose of judging; and c) how we can put
both in writing.

And Keith? - All this is nothing to do with "re-inventing wheels".
Quite the opposite. All we need is a description that is easily
understood WITHOUT delving into the nitty-gritty of what is and isn't
possible. This description MUST be based on what we SEE rather than
any other platform of scientific endeavour. If it doesn't comply with
spherical geometry, then so what? At the end of the day, everything
about flying our Pattern on the surface of a hemisphere is an illusion
anyway, but isn't that the major part of the enjoyment? Who ultimately
cares if a Square loop cannot be done as described, when it's the
illusion that is being flown by the pilot and scored by the judge, and
no amount of technical explanation will ever change that.

Sorry, Peter. This particular Topic has veered a little, but I'm sure
everything will eventually all come together.

Returning to the original point of this discussion - there's still the
question of how we deal with the height of manoeuvre bottoms when the
slope of the ground creates a difference in level flight height on
opposite sides of the flight circle. Do we replace all references in
manoeuvre descriptions from "to the ground" to "to the base"? This
will apply also to the tops of squares - "parallel to base" instead of
"parallel to ground"? - "parallel to level flight'?

Cutting Keith short - A flight path that, to the pilot, is a constant
distance above the nominal ground is "straight" - when it is parallel
to an existing straight line, it cannot be anything else. Whether it
is in fact "straight" is irrelevant! Just part of the illusion. Is
changing the written Rule to encompass this "factual" reality
improving the description? - or merely making matters far more complex
than they need be.

I believe it is time to adopt the KISS Principle - Keep It Simple,
S..........

[Igor Burger]

>>>A flight path that, to the pilot, is a constant distance above the
nominal ground is "straight" - when it is parallel to an existing straight
line, it cannot be anything else. Whether it is in fact "straight" is
irrelevant!<<<

Sorry Ken, I cannot agree. If we have on top of the result list pilots
differing only in 1-2 points, or even in fraction of points, then we must be
sure of perfect understanding of shapes. "parallel to straight is straight"
is just not true. First and most important thing for me as a pilot is
perfect understand what I have to show. And for judges what they have to
expect. And "parallel" and "straight" on 45 deg elevation makes huge
difference. That is why we have to PERFECTLY and I agree with you that
SIMPLY describe the maneuver. That is why we need exact language. Troubles
with four-leaf definition is the best example.

Igor

-----Original Message-----
From: f2b-...@googlegroups.com [mailto:f2b-...@googlegroups.com] On
Behalf Of Ken D
Sent: 14. augusta 2009 9:10
To: F2B Group
Subject: Re: Definition of horizontal, changes suggested

[Ken D]

Hi Igor

I understand what you mean, but to me there is not a better way to
describe it. At any given point in the path of the top of a square, if
the distance is the same, then for all intents and purposes, it is
parallel. It is only when seen as a whole that it is curved - concave
to the square shape. Such is the difficulty of the hemisphere.

However, if we adopt the great circle path as the top of a square,
then it is curved outward - convex to the shape. Added to that, does
the apex of this outward curve happen at the top of the climb, or in
the centre of the shape's top side? How would you write that into the
Rule?

If there is another way to "define" this flight path, then let's find
it. Fortunately, and because the turn radius at each corner is not
anywhere near what the description calls for, the actual length of
this path is very short, so let's not get too caught up with almost
meaningless debate.

The top of the square eight is another debatable point entirely. If we
change this from "parallel" to "great circle", does it apply to the
manoeuvre as a whole, or to each loop individually? If the whole, then
we have a real problem, as the vertical sides would be only 72% of the
height of the centre climb. While I have never see a square eight with
tops that stick at 45 degrees each side, at least that is what pilots
are trying to do, which then keeps the sides the same length as the
centre. Keith's plotting of Werwage's square eight from Muncie 2004
clearly shows the effort made to stay at 45 degrees while flying the
tops - not totally successful but nothing like the way a great circle
path with it's curving down tops would look.

My point is simply that we can very easily become overwhelmed with
technical detail that will not, in the end, change what we do or how
we do it.

[Peter G]

Dear Ken and Igor

there is a discussion here under: "The definition of tops of square
loop manoeuvres " May I suggest to to carry over your so far
contributions and continue your discussion related to the tops of
squares?

Thanks and kind regards

[Keith Renecle]

Hi Ken,

As you say.....we have had this discussion for a long time. It's a real pity
that you were not our workshop in Belgrade, or that you could see one of my
presentations live. Here's the problem. As soon as you make rules about what
a particular person sees, then you open a huge can of worms. Why? because
mostly what people think they see, is often not what the facts show. The
human brain is an amazing device, and I'm sure that you can certainly attest
to the fact that seeing is not always believing. We also often see only what
we want to see. This is where the problem lies at the moment with
international judging. It is based on the belief structure of different
people and there is no real consistency.

Whenever there is a debate on any technical subject like this, you need to
find a common denominator. Some hard and fast rule that is accepted by all.
What we have is a model aircraft that is flying around tethered to the
pilot. Therefore all flight paths are circular, and the hard and fast rules
are all based on extremely basic spherical geometry. There are absolutely NO
straight lines (in the true sense of the word) on spheres. None, zero, nada
etc. etc. Sure if you look at any disc straight on, it can look like
straight or flat, but it is still a circle. Now fortunately for us, the
mathematicians, in their wisdom, figured out and defined a straight line
equivalent. Just like an actual straight line, it is the shortest distance
between two points on a sphere. This is the GREAT CIRCLE. The equatorial
meridian just happens to be one those.

Did you know that there are no parallel great circles on a sphere? You can
only have parallel minor circles. Any shorter circle path is a MINOR CIRCLE
and will project a cone shape if we take this path around 360 degrees.
Flying a minor circle path will require elevator input from the pilot.
Flying a great circle......in any direction..... will have the elevator
fixed trying to keep the model from any deviation from this flight path. I'm
not allowing for gravity, wind and turbulence here, we are talking about
tracking a shape. The point that I'm trying to get across to you, is that
the is a difference between these two flight paths. Why on earth should we
not use the internationally accepted terms for these two distinctly
different flight paths? We can call them Ken and Keith circle if you
like.......but what for? They already have names.

When you say:

> "I am not saying that other great circle paths do
> not exist on our hemisphere, but we cannot SEE them as great circle
> paths or portions thereof, and what we SEE is what is most important
> for both our flying Rules and our Judging observations.

Ken, you say "WE cannot see them as great circle paths" I think that you are
not speaking for everyone. I can see them very easily, and I am no special
person with a gift for seeing these things. I just know what I'm looking
for. Please don't think that I'm being disrespectful or anything here. I've
just trained myself to see this path where the pilot's "lock" their controls
and try to perform the best straight line possible. It does not matter what
the angle is, I see it as clear as day. I come back to my point about the
shapes having nothing to do with how anyone views them. The sides of the
squares, triangles, hourglass are all great circle paths, and are
"spherical" straight lines, no matter how we view them. The sides of the
hourglass look like a large "S" shape from outside the circle, but it does
not change the fact that they are still great circle paths. If you watch the
hourglass being flown properly, you can see clearly that the pilots are
doing everything they know to make sure that their model is flying a dead
straight trajectory towards each corner.

At this point, I think that it will be good to go back to the whole idea of
why it is that we are trying to improve the rules. If the rules were in fact
correct as they are, then I think that there would be no point in trying to
fix them, but the rules are not yet correct. Since Peter Germann and Andy
Sweetland undertook to re-write and improve the rules, I believe that
collectively, we have taken a good step forward. All that we are trying to
do now is to polish off the rough edges and the create a training system
that can improve judging, and when I say improve, I mean that the ultimate
goal is have the same understanding globally.

As Igor rightly says, the standard of the top pilots is so high that it is
very difficult to score the small differences. This takes extra training of
judges to see some of the finer points in each manoeuvre. Judges need to be
able see the difference for example between the curved path of a minor
circle and a straight line path of a great circle. We also need to train new
judges from scratch, and the whole concept of an interactive pc-based
training system, is to bridge the problem of the various languages from all
over our planet. Before we can get to this point, we need a set of rules
with correctly defined shapes. This is where we are right now.

Sorry guys.......this is getting long again, but this illustrates why we

started to try and improve things in the first place. Ken says:
"All we need is a description that is easily
> understood WITHOUT delving into the nitty-gritty of what is and isn't
> possible. This description MUST be based on what we SEE rather than
> any other platform of scientific endeavour. If it doesn't comply with
> spherical geometry, then so what? At the end of the day, everything
> about flying our Pattern on the surface of a hemisphere is an illusion
> anyway, but isn't that the major part of the enjoyment? "

It's the "what WE see" that is the problem. What you see Down Under, is not
necessary the same as someone in the USA, Europe or in Darkest Africa.
Wouldn't it be nice if we were flying shapes that are inded simple, and yet
do comply with spherical geometry? You know what, we are already doing just
that..........in most cases. All the round manoeuvres are perfect spherical
shapes, and so are most of the straight sided manoeuvres. It is almost a
case of having our cake......and eating it. We are just busy with the icing
now!

Just to conclude. (getting there!) You also say further:

"Who ultimately cares if a Square loop cannot be done as described, when
it's the
> illusion that is being flown by the pilot and scored by the judge, and
> no amount of technical explanation will ever change that."

All I can say to that statement is that this philosophy works fine at a club
competition, and there I don't mind being judged by the "old ladies tea-club
from the local church," but when it comes to the world champs, I certainly
do care if I am judged by someone that does ultimately care how the shapes
are described.

Keith R






----- Original Message -----
From: "Ken D" <k...@vicstunt.com>
To: "F2B Group" <f2b-...@googlegroups.com>
Sent: Friday, August 14, 2009 9:10 AM
Subject: Re: Definition of horizontal, changes suggested


>