Optimising regatta starts

As I understand it, a 'regatta start' is where the start line opens at
a specific time and pilots are effectively penalised for starting
before or after this instant. If this interpretation is right, what
methods are used by pilots to estimate their arrival time, and what
maneuvers are used to delay arrival?

On Thu, 15 Nov 2012 22:10:05 +0000, Simon Taylor wrote:

As I understand it, a 'regatta start' is where the start line opens at a
specific time and pilots are effectively penalised for starting before
or after this instant. If this interpretation is right, what methods are
used by pilots to estimate their arrival time, and what maneuvers are
used to delay arrival?

If I'm understanding things correctly, there is a penalty applied for
starting before the line opens. However, as everybody's clock starts when
the line opens, the cost of starting later is the built-in time penalty:
if you start two minutes late, thats 120 secs already on your clock as
you cross the start line.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Thursday, November 15, 2012 5:15:05 PM UTC-5, Simon Taylor wrote:
As I understand it, a 'regatta start' is where the start line opens at a specific time and pilots are effectively penalised for starting before or after this instant. If this interpretation is right, what methods are used by pilots to estimate their arrival time, and what maneuvers are used to delay arrival?

You need to start after the task opens. Orbiting close to the line, assuming lift reasonably close, should make it not too hard. Since a circle only takes about 20 seconds, timing isn't so hard.
What is hard is starting so you line up the lift on course.
These aren't big, hard to turn sailboats.
FWIW
UH

This is how paragliders and hanggliders do it all the times.
They call them Gates, and they can have several of them in a sequence.

LK8000 is dealing with start gates, providing to the pilot the countdown,
the estimated time to get to the start line (or exit the start cylinder),
and suggesting when it is time to go, considering the desired MC set.
It will bring the pilot crossing the start gate 1 second after the gate is
open.
This is fundamental, because the parking thermal may be some miles away from
the start gate, and nevertheless be the good point to wait for the open.

It is a Grand Prix start, at all effects, but with several gates available.
Paragliding people know how to get fun !

paolo


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On Thursday, November 15, 2012 5:15:05 PM UTC-5, Simon Taylor wrote:
As I understand it, a 'regatta start' is where the start line opens at a
specific time and pilots are effectively penalised for starting before or
after this instant. If this interpretation is right, what methods are used
by pilots to estimate their arrival time, and what maneuvers are used to
delay arrival?

You need to start after the task opens. Orbiting close to the line, assuming
lift reasonably close, should make it not too hard. Since a circle only
takes about 20 seconds, timing isn't so hard.
What is hard is starting so you line up the lift on course.
These aren't big, hard to turn sailboats.
FWIW
UH

In my small sailboat racing days (17' catamaran) we'd be checking our timings and heading for the start line in a big group. The goals was to cross the line at full speed just as the starting signal went. If we were early, we'd bear off a bit and reach along the start line, hopefully without running out of start gate, then close-haul and be away.

Of course, with all these boats going full tilt, we'd sometimes have "bumps". Anyone hitting another boat had to do a 360-turn as a penalty (very time consuming in a catamaran). Anyone over the line early had to go back and cross again.

I don't race my glider (yet), but I think I'd be a bit concerned about mid-airs at the start gate. I've been bumped too many times in my sailboat.

On Friday, November 16, 2012 7:51:16 AM UTC-6, C-FFKQ (42) wrote:
In my small sailboat racing days (17' catamaran) we'd be checking our timings and heading for the start line in a big group. The goals was to cross the line at full speed just as the starting signal went. If we were early, we'd bear off a bit and reach along the start line, hopefully without running out of start gate, then close-haul and be away.



Of course, with all these boats going full tilt, we'd sometimes have "bumps". Anyone hitting another boat had to do a 360-turn as a penalty (very time consuming in a catamaran). Anyone over the line early had to go back and cross again.



I don't race my glider (yet), but I think I'd be a bit concerned about mid-airs at the start gate. I've been bumped too many times in my sailboat.

So after years (more decades) of trying to defray start gaggles, dives across the start line at vne+ and all the shenanigans that caused midairs we are reintroducing this dangerous practice? At the end of this noble Grand Prix race will of course have to be worm-burner finishes at 120 knots dumping water because the public and eventual present media is entitled to a good show. Then the mass-landing if all goes "well" and the finishers are close together - of course from a low-energy and low altitude position.
I'm not sure I want to rush to sign up.
Herb, J7

Like sailing, synchronized watches, time and distance. Instead of a cylinder a semi circle or start line (radius, cross section angle) will be defined. It will be quite strategic and difficult to do accurately in many conditions. It will therefore be a lot of fun! It will take some practice leading up to the event for sure. Being "over early" would be a penalty or require a restart I imagine.

On Friday, November 16, 2012 8:22:00 AM UTC-6, Sean F (F2) wrote:
Like sailing, synchronized watches, time and distance. Instead of a cylinder a semi circle or start line (radius, cross section angle) will be defined. It will be quite strategic and difficult to do accurately in many conditions. It will therefore be a lot of fun! It will take some practice leading up to the event for sure. Being "over early" would be a penalty or require a restart I imagine.

Lots of questions remain, Sean. Start altitude, start speed (you can't dive your sailboat from up high), good start/bad start decision, how to deal with inexperienced pilots etc. This maybe something for the Sebastian Kawas to do safely but I predict mayhem with the general soaring and racing public. Better start drafting the releases, get some good lawyers.
Also, tell us about the finish line details. Looks like you are developing all new contest rules, many of which we abandoned long ago for good reasons.

You better not start late in a GP, as the clock is already running.
You really must avoid an early start, as it would be an invalid start.

I make rough mental calculations.
First, I need a climb where to "park" reliably.
I compute the distance vs time. As I think in metric units, I know I
need 1 minute to glide for 2 kms at 120kmh (my best glide speed), or
for 2,5 kms at 150 kmh, or 3 kms at 180 kmh.
So for example, at 120kmh, 8 km out, means I need 4mins. That's 240
seconds, and less than 200 meters of altitude.
So, I can climb to start height + 200m, and start the glide towards
the gate 4 mins in advance.

Or, at 180kmh, I need 2min 40 sec, and roughly 250m.

You might be tempted to fly parallel to the start line, in order to
delay starting to the exact moment, but this would be very dangerous
as you'd be crossing other gliders' paths.

With this basic calculations I never started more than 10 sec late.



aldo cernezzi
www.voloavela.it



On Thu, 15 Nov 2012 22:10:05 +0000, Simon Taylor
wrote:

As I understand it, a 'regatta start' is where the start line opens at
a specific time and pilots are effectively penalised for starting
before or after this instant. If this interpretation is right, what
methods are used by pilots to estimate their arrival time, and what
maneuvers are used to delay arrival?

Thanks to all who responded.