contest corner -- start anywhere

[BB]

I wrote a new "contest corner" for publication in the March Soaring
magazine. It explains the new rule by which you get credit for
distance from the point where you exit the start cylinder in US
contests. Rules geeks who just can't wait can read it on my website,

http://faculty.chicagogsb.edu/john.cochrane/research/Papers/start_anywhere.htm

John Cochrane

[Andy[_1_]]

On Jan 29, 4:15 pm, BB > wrote:
> Rules geeks who just can't wait can read it on my website,

It says "Thus, if you start out the top or back and fly through the
cylinder, you will be forced to start again when you exit the cylinder
a second time. There's no point in trying. "

This was kicked around on RAS. I don't agree you will be forced to
exit the cylinder a second time. I don't see a discussion of an exit
at the back followed by overflight of the cylinder, bumping prestart
gaggles, but not descending below max start height.

I admit I have not studied the new rule yet. What distance is used
for a start out of the top with the cylinder being cleared before
descending below max start height? It used to be distance B but now
is it distance C (not depicted) where C is the distance between the
first turn and the point where the cylinder was exited though the top.

thanks
Andy

[BB]

>*I don't see a discussion of an exit
> at the back followed by overflight of the cylinder, bumping prestart
> gaggles, but not descending below max start height.

With the proposed rule, you are allowed to exit out the back or the
top, and then overfly the start cylinder. You are even allowed to dip
in to the start cylinder, so long as you are not below MSH for 2
minutes. We thought of lots of ways to rule this out but everything
we could think of would have led to a far too complex rule. There are
enough problems with the 2 minute rule; imagine what happens if we
make some rule forcing some separation from the start cylinder.

If you blast through prestart gaggles above the start cylinder you
will still be eligible for unsafe flying penalties, just as if you
were blasting through gaggles on course. I hope this (plus other less
formal sanctions from your fellow pilots, and a bit of common sense)
is enough to keep it from happening.

The rule is "experimental", being tried for regionals this year. One
of many things we should keep our eyes on is whether such gaggle-
bumping turns out to be a problem. If it does, we'll either make the
rule more complex to try to rule it out, or we'll just scrap the whole
business and go back to the old way of doing things.

I envy you Western pilots. I haven't seen the top of the start
cylinder in a long time.

>
> I admit I have not studied the new rule yet. *What distance is used
> for a start out of the top with the cylinder being cleared before
> descending below max start height? *It used to be distance B but now
> is it distance C (not depicted) where C is the distance between the
> first turn and the point where the cylinder was exited though the top.
>

I'm not sure I follow this. If you thermal through the top of the
cylinder, and you do not reenter, your start fix is where you cut the
top of the cylinder. You get credit for distance from this point to
the first turn.

John

[Tuno]

So if I grok all this krektly ...

* A start through the top, where the cylinder is never re-entered, is
scored from the exit point. Cool I like that.

* A start through the top, where the cylinder is re-entered for less
than two minutes while on course, is scored the same distance
(assuming no blasting through gaggles).

* A start through the top, where the cylinder is re-entered for more
than two minutes, will get a different start than the one through the
top.

So one has to be careful after a start through the top in the back of
the cylinder. Several thousand feet of additional altitude may be
necessary to stay clear of the cylinder, especially if the first turn
is upwind.

~ted/2NO

[Andy[_1_]]

On Jan 30, 9:51*am, BB > wrote:
> If you blast through prestart gaggles above the start cylinder you
> will still be eligible for unsafe flying penalties, just as if you
> were blasting through gaggles on course. I

No disagreement here. Unsafe is unsafe and deserves the max penalty.
However in Western contest the bottom of prestart gaggles can be
thousand of feet above MSH allowing a back starter to bump gaggles
without any conflict.

> I'm not sure I follow this. If you thermal through the top of the
> cylinder, and you do not reenter, your start fix is where you cut the
> top of the cylinder. You get credit for distance from this point to
> the first turn.

Ok, that's what I would have expected but this situation is not
depicted in the diagram.

thanks

Andy

[BB]

> So if I grok all this krektly ...

you grok mstly ok


> * A start through the top, where the cylinder is re-entered for less
> than two minutes while on course, is scored the same distance
> (assuming no blasting through gaggles).
>
> * A start through the top, where the cylinder is re-entered for more
> than two minutes, will get a different start than the one through the
> top.

Just to be picky, you lose the earlier start if you enter the cylinder
at all, and have been below MSH for two minutes prior to the
subsequent exit from the cylinder. You don't have to be "in the
cylinder" for 2 minutes, you just have to be "below MSH for two
minutes" and then nick the cylinder. (Sometimes a simple rule leads
to complex explanations)

>
> So one has to be careful after a start through the top in the back of
> the cylinder. Several thousand feet of additional altitude may be
> necessary to stay clear of the cylinder, especially if the first turn
> is upwind.
>

Which is exactly the point. Hopefully, there won't be much traffic
problem in such strong conditions. The big gaggle tends to sit at MSH
- 50 feet in one big thermal with spoilers out doing 100 knots. Still,
keep your eyes open.

John

[chris]

Couldn't a lot of this complexity be eliminated if we
scored to the best point for the pilot on the FRONT 180° of the
clyinder?
[or front 90°] This would better than the currrent optimal exit
point, and less complex than the rule being considered now.



Also with a 5 mile radius start clyinder the maximum distance gained
inside the start cylinder would be 10 miles. It would often be hard
to fly 10 miles upwind without decending back into the start cylinder.


Chris Ruf

[Andy[_1_]]

On Jan 30, 1:48*pm, chris > wrote:
> Couldn't a lot of this complexity be eliminated if we
> scored to the best point for the pilot on the FRONT 180° of the
> clyinder?

But how would you determine where the start sector boundary was if an
area task was being flown. If I remember correctly the old rule
scores based on distance from the start point to the first area
turnpoint (pilot choice) less the start cylinder radius. The 180 deg
sector you propose would be at right angles to an undefined line that
could have a wide range of bearings particularly if the first turn
area is maximum diameter and also min distance from the start.

So my conclusion is that your solution leaves the pilot with no way of
determining the end points of the start sector. The end points of the
sector only become defined after the pilot establishes the first area
turn point.


Andy

[chris]

On Jan 30, 4:42*pm, Andy > wrote:
> On Jan 30, 1:48*pm, chris > wrote:
>
> > Couldn't a lot of this complexity be eliminated if we
> > scored to the best point for the pilot on the FRONT 180° of the
> > clyinder?
>
> But how would you determine where the start sector boundary was if an
> area task was being flown. *If I remember correctly the old rule
> scores based on distance from the start point to the first area
> turnpoint (pilot choice) less the start cylinder radius. * The 180 deg
> sector you propose would be at right angles to an undefined line that
> could have a wide range of bearings particularly if the first turn
> area is maximum diameter and also min distance from the start.
>
> So my conclusion is that your solution leaves the pilot with no way of
> determining the end points of the start sector. The end points of the
> sector only become defined after the pilot establishes the first area
> turn point.
>
> Andy

Couldn't you just use the front 180° between the center of the start
and center of first TP? [same way the current optimal point is
established now]

For MAT task the situation would be the same with each pilot having
their own front 180° figured just like the optimal front point is
figured now [line between start and 1st TP].

Chris

[BB]

> > Couldn't a lot of this complexity be eliminated if we
> > scored to the best point for the pilot on the FRONT 180° of the
> > clyinder?
>
> But how would you determine where the start sector boundary was if an
> area task was being flown.

Yeah, it turns out front 180 is more complex than the current rule. We
started with front 180 as the obvious way to stop the gaggle-bumping
problem, but couldn't get it to work for this and a host of other
problems. Among others: we do want people to be able to thermal out
the top, at least if they are reasonablly close to the front of the
cylinder. (You can't believe how much time and email bandwidth the RC
consumed trying to get a workable rule here!)

>Also with a 5 mile radius start clyinder the maximum distance gained
>inside the start cylinder would be 10 miles. It would often be hard
>to fly 10 miles upwind without decending back into the start cylinder

So don't do it. I regard this "start out the back" stuff as an
unavoidable technicality with the rule, not a strategy the rules
should encourage. We tried hard to rule it out completely, but
couldn't come up with a simple good rule to do so. I will be delighted
if starts out the back half of the cylinder turn out to be unworkable
and hence extremely rare. In fact, if the opposite happens -- if
clever starts out the back turn out to be a common and important
strategy -- I'll bet there will be strong opinion that we should scrap
the whole business.


John

[Tuno]

Chris,

I really don't think it's all that complex. As Andy points out, what
you're suggesting might be even more complex.

I like the new rule because fundamentally, your distance in the first
leg is based on where you exit a three-dimensional cylinder. That is
not complicated at all. The extra language focuses on the two-minute-
under-MSH possibilities, but that, I believe, will rarely present
challenges to pilot or scorer.

This rule will have the effect of reducing crowding at the edge of
start cylinders. That alone is Good Thing.

2NO

[[email protected]]

>
> This rule will have the effect of reducing crowding at the edge of
> start cylinders. That alone is Good Thing.
>
> 2NO


I agree with this Ted's point. I believe in the west in particular
where you can get above MSH with some regularity you will see pilots
looking for the best thermal anywhere inside the cylinder and starting
out the top, or barring that finding a thermal just outside the
cylinder (probably more likely on the front side - but less
concentrated around the direct course line), making a start out the
edge and climbing out that way. Since you will now have starts over
the entire start area, I expect to see less traffic density rather
than more.

I am not worried about trying to engineer our way to preventing people
from bumping gaggles, they do it on course already and we will have
created as much as a 10 mile span to spread out the initial courseline
- that's a lot of territory. My guess it you will see less leeching as
well because it'll be harder to hang out at the likely exit point
since it could be almost anywhere.

9B