How does Winscore calculate finish altitude?

Andy wrote:
On Jul 29, 4:01 pm, Marc Ramsey wrote:
The SN10 also does a pretty good job at this (mine is better, of
course), what's the issue?



The issue is that the the altimeter setting is usually unknown at the
time of landing but it is almost certainly different for the altimeter
setting at takeoff time. The altmeter error on landing, if still
using the takeoff altimeter setting, may exceed 100 feet even if there
is no significant weather change.

SSA competition rules explicitly state that the finish altitude is
determined based on the most favorable (to the pilot) of the baselines
established at *takeoff*, as well as landing. Guy has verified that
Winscore is doing precisely that. If one leaves their glide computer at
the takeoff altimeter setting, or the glide software is able to
calculate a takeoff pressure altitude baseline and uses that to
determine the finish arrival altitude (as mine does), altimeter error is
simply not a factor...

Marc

At 22:18 29 July 2007, Kirk.Stant wrote:
Lots of good points made.

I went flying yesterday and found that my SN10 has
a beatiful digital
pressure altimeter readout, that is automatically calibrated
before
takeoff to field elevation, and can be reset inflight
to the latest
altimeter setting if desired.

I also found that my mechanical POS alitmeter lags
about 100' during a
final glide, showing me that much higher that the SN10's
no-friction
digital readout.

Guess what I'll be using from now on!

Back to the original subject (actually a spin off):

I still think the current hard cutoff at 500 ft is
a poor setup, due
to the difficuty for the pilot to accurately judge
his altitude at the
time of crossing the line. If the goal is to make
pilots finish
higher (for whatever reason), then there needs to be
a finish window
the pilot can aim for that if he accurately figures
his final glide,
will not be penalized. Let's assume we can hit a 200'
window - and
assume that 300' agl is the cutoff for a safe pattern.
Setup the
scoring so anywhere in the 200 ft window (300'agl to
500'agl ) is
neutral - if below the nominal 500', then add the time
it would have
taken to climb in (based on the climb rate in the last
thermal). That
would remove any incentive to finish lower than 500',
but give a
reasonable window to shoot for before a bigger penalty
(automatic
rolling finish score) kicks in.

Comment? Obvious problems?

Kirk
66



Hey Kirk,

I think if you have a 'zero penalty' band pilots will
tend to use it. I can't figure the difference between
and 700' finish with a 200' band and a 500' finish.

If you are going to try to ease up on the current 'all-or-nothing'
system adding a continuous penalty equal to some low,
but not minuscule, rate of climb. I think 30 to 60
seconds per 100' is reasonable. This would amount to
10-20 points on a long task and 20-40 points on a short
task if you finished 500' low - you could set 500'
under as the maximum penalty, or let it scale all the
way to worm-burner finishes (at a mile out!). The maximum
penalty could also apply to rolling finishes, or just
let the penalty for your actual finish height apply
irrespective of whether you roll or do a pattern. After
all, it's the finish height, not the shape of your
pattern that matters.

Or we could leave it to the CD's discretion. Then pilots
might try a little harder to not miss the finish height.

9B

However it is done the one thing I agree on is that it needs to be
very simple so everyone understands it.

I like JJ's plan and it is simlar to what was done at Region 8.

IIRC it was something like
1 to 100 feet low = 5 point penalty
101 to 200 feet = 10 point penalty
201 to 300 feet = 15 point penalty
301 to 400 feet = 20 point penalty
401 to 500 feet = 25 point penalty
etc.

The plan has a lot going for it.
1. It is simple
2. it or variations of the penalty make it only a small penalty to
finish a little low and a larger penalty to finish lower.
3. There is no racing in the finish cylinder. One you enter the
cylinder you can concentrate on landing safely.
4. The penalty is not so severe that there is little incentive to
scratch around low outside the cylinder since unless it is a
reasonable thermal it will be more advantagous to take the penalty
than to take a weak thermal.

Brian
CFIIG/ASEL.

I think if you have a 'zero penalty' band pilots will
tend to use it. I can't figure the difference between
and 700' finish with a 200' band and a 500' finish.

Andy,

My point is that the current system encourages you (the racing pilot)
to shave the 500' limit as close as you can, but at the risk of losing
a lot if you miscalculate - or opt for a low altitude dash to a rushed
landing to minimize your losses. Plus it encourages expensive gadgets/
software (as I now realize that my SN10 will show the info I need, for
example - priced one lately?) and clock watching at the finish.

Providing an "altitude-neutral" band to finish in should remove the
incentive to aim for the bottom, since there would no longer be a
benefit to be gained, while the risk of losing a lot would be a strong
incentive to aim for the top of the finish band. The band should be
big enough to hit easily with a properly set regular altimeter (I
think 200' would work) without being so big the adjustment for
altitude becomes "gameable".

Heck, how about adding one second for every 2 feet below the top -
that works out to a 1.2 knot final climb - which wouldn't hurt you
much if you were 20 ft low, but would still encourage not finishing
199 ft low (who wants to give away time, after all).

The addition of "no racing after the finish" (i.e. if below the
bottom, the "hard deck" in fighter speak, you get your finish and
penalty right there and can forget about a straight in finish and
concentrate on making a safe low altitude landing) would additionally
discourage high risk finishes.

I know, I know, enough whining, this is pretty much beat to death -
time to start bashing 2-33s again...

Cheers,

Kirk

kirk.stant wrote:
....
My point is that the current system encourages you (the racing pilot)
to shave the 500' limit as close as you can, but at the risk of losing
a lot if you miscalculate -

Kirk,

Doesn't the old fashioned system encourage you to finish at 50 ft
altitude and 70-90 knots airspeed (whatever was MC speed for your last
thermal) ? Each pilot added extra margin for their own comfort, but
the scoring encouraged them to leave no margin.

Todd Smith
3S

On Jul 30, 9:23 am, toad wrote:
kirk.stant wrote:

...

My point is that the current system encourages you (the racing pilot)
to shave the 500' limit as close as you can, but at the risk of losing
a lot if you miscalculate -

Kirk,

Doesn't the old fashioned system encourage you to finish at 50 ft
altitude and 70-90 knots airspeed (whatever was MC speed for your last
thermal) ? Each pilot added extra margin for their own comfort, but
the scoring encouraged them to leave no margin.

Todd Smith
3S

Absolutely. But the big difference is that I can SEE 50'. And
depending on the field conditions and approaches, you either added a
big pad (small field, no options if too low) or could push it lower
(lots of available runways, landable fields on the approaches). Since
these decisions affected all the pilots competing, they really even
out - since the penalty for landing just short are really extreme!

But move that up to 500' and you cannot eyeball the finish anymore -
so you either have to throw in a big pad (bogus from a racing
standpoint) or take a big racing risk. Or play the rule and bypass
the safety issue altogether.

People keep on harping how the scoring encourages pilots to leave no
margin. Uh, excuse me, but do you know of any competitive sport that
doesn't? That's why it's called a race! But at the same time, you
can't win by crashing - and as pilot in command it is entirely my
responsibility to not exceed my skill and equipment performance while
completing the task - as close to the margin as rules allow.

Heck, in boat racing, some of the rules encourage collisions (try
being on the start boat end of a Laser start - I've been right-of-
wayed right into the boat by a serious competitor - and properly so)!
Thankfully we aren't that aggressive in soaring (although a limited
altitude start gaggle gets pretty close!).

Now before you accuse me of being a daredevil (I've been called worse)
let me say that I have no problem with rules that encourage a safe
finish by not requireing a dangerous finish. But the rule has to
consider the Race aspect as much as the Safety aspect. Our current
finish cylinder rule does not, IMO.

Sorry, I promise to get help...

Kirk

On Jul 30, 10:56 am, "kirk.stant" wrote:
On Jul 30, 9:23 am, toad wrote:



kirk.stant wrote:

...

My point is that the current system encourages you (the racing pilot)
to shave the 500' limit as close as you can, but at the risk of losing
a lot if you miscalculate -

Kirk,

Doesn't the old fashioned system encourage you to finish at 50 ft
altitude and 70-90 knots airspeed (whatever was MC speed for your last
thermal) ? Each pilot added extra margin for their own comfort, but
the scoring encouraged them to leave no margin.

Todd Smith
3S

Absolutely. But the big difference is that I can SEE 50'. And
depending on the field conditions and approaches, you either added a
big pad (small field, no options if too low) or could push it lower
(lots of available runways, landable fields on the approaches). Since
these decisions affected all the pilots competing, they really even
out - since the penalty for landing just short are really extreme!

I see you point about being able to visually identify 50' altitude,
but I disagree
that the decisions even out. Because pilot A can choose to leave 0'
margin, but
pilot B chooses 500' margin.


But move that up to 500' and you cannot eyeball the finish anymore -
so you either have to throw in a big pad (bogus from a racing
standpoint) or take a big racing risk. Or play the rule and bypass
the safety issue altogether.

People keep on harping how the scoring encourages pilots to leave no
margin. Uh, excuse me, but do you know of any competitive sport that
doesn't?

Competitive and dangerous sports build the desired minimums into the
rules.
Car races limit engine horsepower, mandate strength standards and
safety equipment,
this all makes the cars slower. Sailboats require certain safety
equipment, etc.
Whitewater races are required to wear life jackets and helmets.


Heck, in boat racing, some of the rules encourage collisions (try
being on the start boat end of a Laser start - I've been right-of-
wayed right into the boat by a serious competitor - and properly so)!
Thankfully we aren't that aggressive in soaring (although a limited
altitude start gaggle gets pretty close!).

Well, you should have known there was no room in there before you
barged !
Most sailboat ROW issues don't have the consequences of a short
landing.

Now before you accuse me of being a daredevil (I've been called worse)
let me say that I have no problem with rules that encourage a safe
finish by not requireing a dangerous finish. But the rule has to
consider the Race aspect as much as the Safety aspect. Our current
finish cylinder rule does not, IMO.

I think that the details might need to be tweaked, but the rule does
try to
consider the racing as well as the safety. The old rule ignored
safety and left that part
to the pilot.

Maybe we need a tethered balloon with a laser level to mark finish
height ;-)


Sorry, I promise to get help...

Just go fly.


Kirk

Todd Smith
3S

I don't find this to be true, Andy. Altimeters need
to be re-set primarily when landing at a destination
1000's of miles away from the takeoff location. I find
my altimeter to be surprisingly accurate when landing
at my takeoff location after a 4 hour flight. This
is true with the SN10 altineter, also.
JJ


The issue is that the the altimeter setting is usually
unknown at the
time of landing but it is almost certainly different
for the altimeter
setting at takeoff time. The altmeter error on landing,
if still
using the takeoff altimeter setting, may exceed 100
feet even if there
is no significant weather change.

Andy

I don't find this to be true, Andy. Altimeters need
to be re-set primarily when landing at a destination
1000's of miles away from the takeoff location. I find
my altimeter to be surprisingly accurate when landing
at my takeoff location after a 4 hour flight. This
is true with the SN10 altineter, also.
JJ


The issue is that the the altimeter setting is usually
unknown at the
time of landing but it is almost certainly different
for the altimeter
setting at takeoff time. The altmeter error on landing,
if still
using the takeoff altimeter setting, may exceed 100
feet even if there
is no significant weather change.

Andy

On Jul 30, 7:21 am, John Sinclair
wrote:
I don't find this to be true, Andy. Altimeters need
to be re-set primarily when landing at a destination
1000's of miles away from the takeoff location.

We have an AWOS right on the airport, so I set the mechanical and 302
to this shortly before takeoff. When I check the altimeter after 4-6
hours, the change is typically 1-200' - and usually puts me lower.
Really unsettling if I'm on a marginal glide and the air looks stable
ahead.

-Tom