2009 Proposed US Contest Rules Changes

Hi Race Fans
The proposed contest rules changes for 2009 are available at the SSA
web site under Sailplane Racing/Rules& Process. Due to a long time in
developing some of these changes the comment period will be quite
short. Please comment to RC members by 1/7/2009. Debate on this site
will be used as grist for coming activities but is not considered
formal feedback.
Respectfully submitted
For the Rules Subcommittee
H Nixon RC Chair

On Jan 3, 3:31*pm, wrote:
Hi Race Fans
The proposed contest rules changes for 2009 are available at the SSA
web site *under Sailplane Racing/Rules& Process. Due to a long time in
developing some of these changes the comment period will be quite
short. Please comment to RC members by 1/7/2009. Debate on this site
will be used as grist for coming activities but is not considered
formal feedback.
Respectfully submitted
For the Rules Subcommittee
H Nixon *RC Chair

(quote) Rule 10.8.6 has been changed such that starts will only
receive distance credit for distance flown from the“front” half of a
start cylinder.

The distance of the first task leg shall be taken as the distance from
the Start
Position to the control fix at the first turnpoint, but not greater
than the distance
from the Start Point to that control fix. (end quote)

The change to rule 10.8.6 appears to be intended to discourage starts
from the back half of the start cylinder. The comment suggests that
any start from the front half will score actual distance flown.
However, it appears that pilots starting near the back boundary of the
front half may fly non scoring distance without realizing it.

Consider the following worst case: Start cylinder 5 mile radius, area
task with first control area of 30 mile radius, center of first turn
area is 40 miles from start point. This gives a minimum first leg of
5 miles.

The proposed rule states - The distance of the first task leg shall be
taken as the distance from the Start Position to the control fix at
the first turnpoint, but not greater than the distance from the Start
Point to that control fix. This means the full score area of the
start cylinder is defined by an arc drawn from the first area control
fix through the start point. If the control fix happens to be near
the center of the first turn area then the arc will intersect the
start cylinder edges close to the straight line that defines the front
half. However, if the pilot chooses to turn anywhere except on a
straight line drawn through the start point and the first control
point, the arc will intersect the start cylinder away from the front
half line. The extreme case appears to be when the first turnpoint
control fix is on the edge of the turn area at a point that is on a
tangent drawn from the start point. There are two such points.

The worse case scenario is realized when a pilot starts the task close
to the edge of the back half on the assumption he will fly to one
tangent point and, because of a change in conditions, actually flies
to the other tangent point.

In a simple graphic analysis of the defined task I estimated a
distance of over 8 miles of start cylinder circumference between the
intersections of the two extreme case arcs and the start circle. In
other words, the potential front half circumference of approx 31.4
miles is reduced to a no risk arc of approx 23.4 miles. Someone with a
greater enjoyment of math will come up with a more accurate answer.

How, with the proposed rule change, is the pilot expected to know
whether the selected start cylinder exit point will result in a
devalued first leg distance?

Andy

On Jan 6, 3:25*pm, Andy wrote:
On Jan 3, 3:31*pm, wrote:

Hi Race Fans
The proposed contest rules changes for 2009 are available at the SSA
web site *under Sailplane Racing/Rules& Process. Due to a long time in
developing some of these changes the comment period will be quite
short. Please comment to RC members by 1/7/2009. Debate on this site
will be used as grist for coming activities but is not considered
formal feedback.
Respectfully submitted
For the Rules Subcommittee
H Nixon *RC Chair

(quote) Rule 10.8.6 has been changed such that starts will only
receive distance credit for distance flown from the“front” half of a
start cylinder.

The distance of the first task leg shall be taken as the distance from
the Start
Position to the control fix at the first turnpoint, but not greater
than the distance
from the Start Point to that control fix. (end quote)

The change to rule 10.8.6 appears to be intended to discourage starts
from the back half of the start cylinder. *The comment suggests that
any start from the front half will score actual distance flown.
However, it appears that pilots starting near the back boundary of the
front half may fly non scoring distance without realizing it.

Consider the following worst case: *Start cylinder 5 mile radius, area
task with first control area of 30 mile radius, center of first turn
area is 40 miles from start point. *This gives a minimum first leg of
5 miles.

The proposed rule states - The distance of the first task leg shall be
taken as the distance from the Start Position to the control fix at
the first turnpoint, but not greater than the distance from the Start
Point to that control fix. *This means the full score area of the
start cylinder is defined by an arc drawn from the first area control
fix through the start point. *If the control fix happens to be near
the center of the first turn area then the arc will intersect the
start cylinder edges close to the straight line that defines the front
half. * However, if the pilot chooses to turn anywhere except on a
straight line drawn through the start point and the first control
point, the arc will intersect the start cylinder away from the front
half line. * The extreme case appears to be when the first turnpoint
control fix is on the edge of the turn area at a point that is on a
tangent drawn from the start point. There are two such points.

The worse case scenario is realized when a pilot starts the task close
to the edge of the back half on the assumption he will fly to one
tangent point and, because of a change in conditions, actually flies
to the other tangent point.

In a simple graphic analysis of the defined task I estimated a
distance of over 8 miles of start cylinder circumference between the
intersections of the two extreme case arcs and the start circle. *In
other words, the potential front half circumference of approx 31.4
miles is reduced to a no risk arc of approx 23.4 miles. Someone with a
greater enjoyment of math will come up with a more accurate answer.

How, with the proposed rule change, is the pilot expected to know
whether the selected start cylinder exit point will result in a
devalued first leg distance?

Andy

I had to read that one three times -- and get out my daughter's high-
school geometry textbook ;-)

I had a similar reaction - but without the analytic rigor. Andy, I
assume you were using the minimum first leg distance (is there a
minimum beyond the cylinders not touching?) coupled with the maximum
turn area radius (30 mi). It's a problem in that the acceptable start
locations are not defined until after a pilot starts, and even if it
were defined, it's hard for a pilot to know for certain if they are in
the "front half".

I am assuming that the problem this is designed to solve is the one of
pilots starting out the top near the back of the cylinder and bumping
gaggles on the way to the front. Maybe others have seen this happen
but I have not, and I can't imagine anyone starting out the back side
of the cylinder. So I wonder if it is worth the complexity to solve a
problem that may not exist - at least not to a significant extent.

9B

9B

On Jan 6, 5:26*pm, wrote:
On Jan 6, 3:25*pm, Andy wrote:





On Jan 3, 3:31*pm, wrote:

Hi Race Fans
The proposed contest rules changes for 2009 are available at the SSA
web site *under Sailplane Racing/Rules& Process. Due to a long time in
developing some of these changes the comment period will be quite
short. Please comment to RC members by 1/7/2009. Debate on this site
will be used as grist for coming activities but is not considered
formal feedback.
Respectfully submitted
For the Rules Subcommittee
H Nixon *RC Chair

(quote) Rule 10.8.6 has been changed such that starts will only
receive distance credit for distance flown from the“front” half of a
start cylinder.

The distance of the first task leg shall be taken as the distance from
the Start
Position to the control fix at the first turnpoint, but not greater
than the distance
from the Start Point to that control fix. (end quote)

The change to rule 10.8.6 appears to be intended to discourage starts
from the back half of the start cylinder. *The comment suggests that
any start from the front half will score actual distance flown.
However, it appears that pilots starting near the back boundary of the
front half may fly non scoring distance without realizing it.

Consider the following worst case: *Start cylinder 5 mile radius, area
task with first control area of 30 mile radius, center of first turn
area is 40 miles from start point. *This gives a minimum first leg of
5 miles.

The proposed rule states - The distance of the first task leg shall be
taken as the distance from the Start Position to the control fix at
the first turnpoint, but not greater than the distance from the Start
Point to that control fix. *This means the full score area of the
start cylinder is defined by an arc drawn from the first area control
fix through the start point. *If the control fix happens to be near
the center of the first turn area then the arc will intersect the
start cylinder edges close to the straight line that defines the front
half. * However, if the pilot chooses to turn anywhere except on a
straight line drawn through the start point and the first control
point, the arc will intersect the start cylinder away from the front
half line. * The extreme case appears to be when the first turnpoint
control fix is on the edge of the turn area at a point that is on a
tangent drawn from the start point. There are two such points.

The worse case scenario is realized when a pilot starts the task close
to the edge of the back half on the assumption he will fly to one
tangent point and, because of a change in conditions, actually flies
to the other tangent point.

In a simple graphic analysis of the defined task I estimated a
distance of over 8 miles of start cylinder circumference between the
intersections of the two extreme case arcs and the start circle. *In
other words, the potential front half circumference of approx 31.4
miles is reduced to a no risk arc of approx 23.4 miles. Someone with a
greater enjoyment of math will come up with a more accurate answer.

How, with the proposed rule change, is the pilot expected to know
whether the selected start cylinder exit point will result in a
devalued first leg distance?

Andy

I had to read that one three times -- and get out my daughter's high-
school geometry textbook ;-)

I had a similar reaction - but without the analytic rigor. Andy, I
assume you were using the minimum first leg distance (is there a
minimum beyond the cylinders not touching?) coupled with the maximum
turn area radius (30 mi). It's a problem in that the acceptable start
locations are not defined until after a pilot starts, and even if it
were defined, it's hard for a pilot to know for certain if they are in
the "front half".

I am assuming that the problem this is designed to solve is the one of
pilots starting out the top near the back of the cylinder and bumping
gaggles on the way to the front. Maybe others have seen this happen
but I have not, and I can't imagine anyone starting out the back side
of the cylinder. So I wonder if it is worth the complexity to solve a
problem that may not exist - at least not to a significant extent.

9B

9B- Hide quoted text -

- Show quoted text

How do I "clearly" know where to turn in the turn area now?
Hmmmm.......need something with maybe a red arc in the turn area from
the start fix from where I started in start cylinder. This is what I
"clearly" need.
It would be to "easy" to have just a start circle with a max. start
height, since now we can exit anywhere along the side of the cylinder.
We had the exit out the top because of only one prime exit point and
that was to help spread out the folks. But now we can exit anywhere
along the radius of the cylinder, so why do we still need to exit out
the top???? Hmmmmmmmm......where's that brown cow.......

Thermal tight, Soar high, spend more money and look inside...........
711.

On Jan 6, 5:26*pm, wrote:

I had to read that one three times -- and get out my daughter's high-
school geometry textbook ;-)

And I thought you would be the one that provided the answer to 4
decimal places!

Andy

"Andy" wrote in message
...
On Jan 6, 5:26 pm, wrote:

I had to read that one three times -- and get out my daughter's high-
school geometry textbook ;-)

And I thought you would be the one that provided the answer to 4
decimal places!

Andy

If I read this correctly, the scored first leg distance is unknown until the
first turn is made? Still, one never really knows how far you will fly, so
does it matter? The object is to run out the clock, and you don't really
know how it will go till about half the flight, and you see the conditions
ahead.

The power of prophecy would be very handy.

Hartley Falbaum
USA "KF"

On Jan 7, 7:20*am, "HL Falbaum" wrote:

If I read this correctly, the scored first leg distance is unknown until the
first turn is made?

No, while that is true, it is not the point I wished to make.

To understand the issue you need a picture of the task I described
showing the tangent points and the arcs that intersect the start
cylinder. Since I can't provide that you will need to draw it
yourself.

The point I wished to make is that the area of the start cylinder that
will give full credit for first leg distance is dependent on the
position of the first turn area control fix (the pilot selected turn
point). Since the position of that control fix is unknown when the
start point is selected, the pilot takes a risk when starting in some
areas in the front half. The no risk area of the start cylinder is
not the "front half" but an area that may be considerably smaller than
the "front half". That no risk area is defined by the area of overlap
between the two arcs drawn from the turn area tangent points.

Note that no start penalty will show on the score sheet, you just lose
distance that you thought was part of your first leg. This makes it a
hidden penalty and most pilots would not even realize they had lost
points as a result of the chosen start point.

This will be of particular interest to SW pilots that often start out
of the top and needs to be understood by anyone flying at R9 Parowan
unless the proposed rule change is abandoned.


Andy

On Jan 7, 8:34*am, Andy wrote:
On Jan 7, 7:20*am, "HL Falbaum" wrote:



If I read this correctly, the scored first leg distance is unknown until the
first turn is made?

No, while that is true, it is not the point I wished to make.

To understand the issue you need a picture of the task I described
showing the tangent points and the arcs that intersect the start
cylinder. *Since I can't provide that you will need to draw it
yourself.

The point I wished to make is that the area of the start cylinder that
will give full credit for first leg distance is dependent on the
position of the first turn area control fix (the pilot selected turn
point). *Since the position of that control fix is unknown when the
start point is selected, *the pilot takes a risk when starting in some
areas in the front half. *The no risk area of the start cylinder is
not the "front half" but an area that may be considerably smaller than
the "front half". *That no risk area is defined by the area of overlap
between the two arcs drawn from the turn area tangent points.

Note that no start penalty will show on the score sheet, you just lose
distance that you thought was part of your first leg. *This makes it a
hidden penalty and most pilots would not even realize they had lost
points as a result of the chosen start point.

This will be of particular interest to SW pilots that often start out
of the top and needs to be understood by anyone flying at R9 Parowan
unless the proposed rule change is abandoned.

Andy

Okay - you shamed me into doing the math (only one decimal place).

I agree with Andy that the rule creates a potential problem because it
defines the "front half" of the cylinder as the circular arc centered
on the "control fix" in the first turn area (that's the place where
Winscore determines you made the turn) that passes through the center
of the start cylinder.

To visualize this draw two circles on a piece of paper - one has a
radius of 5 units (this is the start cylinder). Draw the second with a
radius of 30 units, just above the first and touching at the edge.
Your diagram now looks like a simple drawing of a soccer ball sitting
on top of a baseball. This is the worst case scenario - the biggest
possible first turn area (30 mi) sitting as close as possible to the
start cylinder (somebody check me that there isn't some minimum first
leg distance in the rules that is greater than 35 miles).

Now imagine two pilots - one pilot who thinks conditions look best to
the extreme right edge of the first turn area and another who thinks
the extreme left edge of the turn area looks best. Each pilot
contemplates what their "front half" of the start cylinder will be if
they fly as they intend to the right/left sides of the turn area. The
first pilot figures on a "front half" that is rotated to the right by
some number of degrees to reflect his expected rightward courseline.
The second pilot figures on a "front half" that is rotated to the left
by an equivalent angle. Based on strategy (or just where the lift is)
each pilot takes a start from the far corner of their respective semi
circles (not exactly a semicircle since it's defined by an arc, but I
don't have a word for that shape). The first pilot to the right and
the second pilot to the left.

Each pilot heads out on course, but a few miles out each notices
something that makes them change their plan (a cu popping, a fast-
climbing competitor, whatever). Each now decides to go the the
opposite side of the first turn area from their initial plan - and
does so. They fly the course, land and turn in their flight logs. When
the scores come back they find themselves scored for less distance
than they thought. They go to the scorer who looks at the logs and
discovers that when each pilot changed their first turn point they
rotated the first leg course line and thereby rotated the allowed
"front half" of the start cylinder. For scoring purposes each pilot
started miles outside their respective "front half" and had their
first leg distance reduced by that amount.

So now the math part:

In the worst case scenario described above it is possible for the
"front half" of the start cylinder to be rotated plus or minus 51.3
degrees to the left or right of the line between the center of the
start cylinder and the center of the first turn area. This means that
if you are either of the pilots in the above example you will be
scored for 5 miles less than you actually flew.

So how might pilots respond to this? One possibility it that pilots
might play it totally safe and start out of the part of the cylinder
where all possible first turnpoint "fixes" can be reached without
penalty. If you do the math this is an arc with an angle of 77.3
degrees centered on the line from the center of the start cylinder to
the center of the first turn area. This "safe arc" has a length of 6.7
miles rather than 31.4 miles for a full "front half" of the cylinder.
The other possibility is that pilots who don't start in this "safe
arc" will feel compelled to press on to their initially planned
turnpoint out of concern that they will be docked miles if they
change. For some flights you may need to have Winscore recalculate the
control fix in the first turn to trade off distance lost at the start
versus distance made at the turn - that would be funky.

I realize this is the worst case scenario and that the first turn area
may likely be a bit further away than 35 miles or smaller than 30
miles in radius - particularly in the west. This would make the "safe
arc" for starting bigger than I describe.The big issue in my mind,
though, is that it is impossible to know ahead of time what is the
allowable start half-cylinder for any flight and therefore pilots will
tend to funnel back toward the front edge of the cylinder to be safe
and to keep their options open, the opposite of what "start anywhere"
is intended to achieve.

Also, I am not sure that this is a rule change that solves a problem
that exists in practice. I presume the thing the RC wants to avoid is
pilots starting out the top of the back of the cylinder and bombing
through start gaggles. I'm not saying it can't happen, I just haven't
seen it.

I'm sure that was clear as mud.

9B

On Jan 7, 1:04*pm, wrote:
To visualize this draw two circles on a piece of paper - one has a
radius of 5 units (this is the start cylinder). Draw the second with a
radius of 30 units, just above the first and touching at the edge.
Your diagram now looks like a simple drawing of a soccer ball sitting
on top of a baseball. This is the worst case scenario - the biggest
possible first turn area (30 mi) sitting as close as possible to the
start cylinder (somebody check me that there isn't some minimum first
leg distance in the rules that is greater than 35 miles).


Close, but you have confused the issue by using an invalid task
example. The minimum separation between the closest points of the
start cylinder and the first turn area is 5 statute miles. See rule
10.3.1.1.

Andy

On Jan 7, 12:28*pm, Andy wrote:
On Jan 7, 1:04*pm, wrote:

To visualize this draw two circles on a piece of paper - one has a
radius of 5 units (this is the start cylinder). Draw the second with a
radius of 30 units, just above the first and touching at the edge.
Your diagram now looks like a simple drawing of a soccer ball sitting
on top of a baseball. This is the worst case scenario - the biggest
possible first turn area (30 mi) sitting as close as possible to the
start cylinder (somebody check me that there isn't some minimum first
leg distance in the rules that is greater than 35 miles).

Close, but you have confused the issue by using an invalid task
example. *The minimum separation between the closest points of the
start cylinder and the first turn area is 5 statute miles. *See rule
10.3.1.1.

Andy

Thanks Andy,

RTFR - I was afraid of that. I'll redo the math.

Andy