How does Winscore calculate finish altitude?

Good post Andy, but I believe we need a set penalty
to discourage deliberately doing a rolling finish on
a good day. I watched a well known pilot make a rolling
finish every day for 5 days in a row (1000 feet and
2 mile finish cylinder). I have recommended the rules
committee consider the following:

up to 100 feet low = 5 point penalty
up to 200 feet low = 10 point penalty
up to 300 feet low = 15 point penalty
up to 400 feet low = 20 point penalty
rolling finish = 25 point penalty
JJ

Should read:

For a 4-hour task the 4 points per 100' drops to 2
points per 100'.

9B

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

kirk.stant wrote:
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?

I'd suggest the opposite. I think I should be rewarded for every foot
that I have over the minimum finish height of, say, 500' AGL. So, if I
finish at 2000' AGL, I should get the actual time I spent climbing the
last 1500' deducted from my task time. It's more accurate, and it
favors my chosen strategy, what's not to like? 8^)

In reality, any halfway decent glide computer, or software with access
to pressure altitude, will prior to takeoff either automatically
determine the field elevation or let the pilot set it manually. The
same sort of problem exists with the start cylinder if one can climb to
the top. The glide software I use (which I wrote) automatically
determines field elevation just prior to takeoff. It monitors my
altitude in the start cylinder, signals me if I climb through the top
and does a countdown when I reenter, provides progressive warnings as I
approach the hard altitude limit (usually 17500' MSL out here), and
automatically adjusts my arrival altitude based on the minimum finish
height, all based on that initial field elevation measurement. I'm
confident that this will work within a margin of 10 or 20 feet, as it
using the pressure altitude that will ultimately show up in the IGC
file, and I don't have to pay much attention to any of it.

The SN10 also does a pretty good job at this (mine is better, of
course), what's the issue?

Marc

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.

Andy

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