Is the 200ft below Min Finish Height Rule Working?

On Monday, January 20, 2014 5:12:21 PM UTC-8, wrote:

Clearly there was a big departure from gradual penalty to the land out penalty. Big change that moved the dangerous flying outside the finish cylinder. Why the land out penalty. I don't think the land out penalty was well thought through.

The land out penalty should be rolled back and gradual penalty should come back if any.

It mostly boils down to whether you believe there should be a significant points benefit for making a finish at an altitude from which it is impossible to reach the airport. That's a powerful incentive to roll the dice. Should winning hinge on betting your glider (and your life) in exchange for points in that way?

The rest is just math - and how low you set MFH.

9B

On Monday, January 20, 2014 9:04:44 PM UTC-5, wrote:
On Monday, January 20, 2014 5:12:21 PM UTC-8, wrote:



Clearly there was a big departure from gradual penalty to the land out penalty. Big change that moved the dangerous flying outside the finish cylinder. Why the land out penalty. I don't think the land out penalty was well thought through.



The land out penalty should be rolled back and gradual penalty should come back if any.



It mostly boils down to whether you believe there should be a significant points benefit for making a finish at an altitude from which it is impossible to reach the airport. That's a powerful incentive to roll the dice. Should winning hinge on betting your glider (and your life) in exchange for points in that way?



The rest is just math - and how low you set MFH.



9B

You did not provide a logical reason why this big change (scoring as land out) was made rather then just raising the finish height and leaving gradual penalty.

You did not address any problem you just moved the problem somewhere else.

You did not provide a logical reason why this big change (scoring as land out) was made rather then just raising the finish height and leaving gradual penalty.

The point of scoring low finishes as a landout is real simple. When you're deciding "shall I land in the last good field or press on" at MacCready 0 plus 50 feet, it needs to be crystal clear that you will gain nothing by pressing on. This is not safety legislation -- points are off the table, make a good decision, points are the same either way. With a graduated penalty there is always some benefit to pressing on. And complexity. Didn't you guys want simple rules? Try figuring out the points to finish 397 feet low.

It just moves the hard ground down. You used to be scored as a landout -- with none of this mollycoddling graduated penalties -- if you missed the fence by a foot.

Don't think of it as a "penalty." The task is to start below (say) 5000', get inside three turnpoints, and finish no less than (say) 700'. If you didn't do that, you didn't fly the same race as everyone else. In what other sport can you miss the finish line by 200 feet and still get a "finish?" And want more?

John Cochrane

Have there been quite a few serious accidents (injury or fatality) from stretching a final glide in US contests? I know of one fatality years ago but the pilot had plenty of altitude to land straight ahead and instead attempted a low pass and pattern with insufficient altitude. Just wanted to make certain that this is not a solution in search of a problem.

On Monday, January 20, 2014 10:20:15 PM UTC-5, wrote:


You did not provide a logical reason why this big change (scoring as land out) was made rather then just raising the finish height and leaving gradual penalty.



The point of scoring low finishes as a landout is real simple. When you're deciding "shall I land in the last good field or press on" at MacCready 0 plus 50 feet, it needs to be crystal clear that you will gain nothing by pressing on. This is not safety legislation -- points are off the table, make a good decision, points are the same either way. With a graduated penalty there is always some benefit to pressing on. And complexity. Didn't you guys want simple rules? Try figuring out the points to finish 397 feet low.



It just moves the hard ground down. You used to be scored as a landout -- with none of this mollycoddling graduated penalties -- if you missed the fence by a foot.



Don't think of it as a "penalty." The task is to start below (say) 5000', get inside three turnpoints, and finish no less than (say) 700'. If you didn't do that, you didn't fly the same race as everyone else. In what other sport can you miss the finish line by 200 feet and still get a "finish?" And want more?



John Cochrane

John, you are saying this is not "a safety legislature" then what is it? What was the purpose of this change, more fun?

This rule does not change behavior. If old rules were in effect a pilot would try to make it to the field and he would get there say at 450 feet (safe).

According to the new rule he thinks he can not loose so many points by being scored as land out. So what does he do? He says oh well I am going to try to thermal low on final glide in hope of finding the missing points instead of ending up safely at the field at 450 feet and accepting penalty according the old rules.

This rule creates a bad incentive. You just changed one not so bad situation for much worse.

You just can't fix the world. Smart pilot will think about going home safely to his family a not so smart pilot will take risks no matter what.

Let's not cry out about how bad finishes are in Europe. We already had the 500 feet we did not need any more improvement. What is next? This never ends like it did not end on 500 feet.

On Monday, January 20, 2014 6:42:14 PM UTC-8, wrote:

You did not provide a logical reason why this big change (scoring as land out) was made rather then just raising the finish height and leaving gradual penalty.

The reason and logic and review and deliberation is in the RC meeting notes.. To recap:

Logical reason is you should not present competitors with a situation where they can score higher points by deciding to go for the finish cylinder at an altitude from which they cannot reach the airport.

You are correct, you could set (based on current rules for max distance from the airport and max radius of the finish cylinder) a mandatory MFH of around 1250' and a graduated penalty of around a point per foot. If you force a smaller, closer finish cylinder you can bring MFH down a bit, but there are serious objections to a higher MFH based on airport configuration, proximity to ridge, etc.

Again, If this explanation doesn't suffice I'd be happy to walk anyone through the math and logic offline.

9B

Op maandag 20 januari 2014 21:21:11 UTC+1 schreef :

On Monday, January 20, 2014 3:03:41 PM UTC-5, J. Nieuwenhuize wrote:
Why not use the total height? So height (AGL) plus potential height (speed²/(2*a)) That makes ballistic pull-ups useless, allows, actually favors smooth finishes. Then set the total height rather high and substract one point per feet too low.

Simply put- because this becomes a pilot and scoring nightmare. Note that each glider converts kinetic energy to potential energy differently.
UH


Not really; in fact they do it exactly the same way. Even an unballasted club class glider looses only a few percent (due to drag during the pull-up). Since virtually all pilots fly with a TE energy system and rely exclusively on it, I highly doubt it'd be a pilots nightmare.

The ideal finish with a fixed height finish line/circle (or point substraction when too low) is fairly straightforward; fly at best MC, say 100 kts and pull up agressively, just before the finish ring. Exactly the opposite of what you'd want...

A hard deck within - say - 4 miles from the finish line is a simple alternative. Get below finish height and you're scored as a land-out.

On Tuesday, January 21, 2014 7:14:15 AM UTC-5, J. Nieuwenhuize wrote:
Op maandag 20 januari 2014 21:21:11 UTC+1 schreef : On Monday, January 20, 2014 3:03:41 PM UTC-5, J. Nieuwenhuize wrote: Why not use the total height? So height (AGL) plus potential height (speed²/(2*a)) That makes ballistic pull-ups useless, allows, actually favors smooth finishes. Then set the total height rather high and substract one point per feet too low. Simply put- because this becomes a pilot and scoring nightmare. Note that each glider converts kinetic energy to potential energy differently. UH Not really; in fact they do it exactly the same way. Even an unballasted club class glider looses only a few percent (due to drag during the pull-up). Since virtually all pilots fly with a TE energy system and rely exclusively on it, I highly doubt it'd be a pilots nightmare. The ideal finish with a fixed height finish line/circle (or point substraction when too low) is fairly straightforward; fly at best MC, say 100 kts and pull up agressively, just before the finish ring. Exactly the opposite of what you'd want... A hard deck within - say - 4 miles from the finish line is a simple alternative. Get below finish height and you're scored as a land-out.

You are suggesting an alternative that requires computation in the cockpit to allow for kinetic energy and then asking the scorer to do the same. The current systems use direct measurement of one attribute (height) measured with a simple existing instrument and easily verifiable by the scorer.
The glide final scenario you describe is actaully not optimum. A perfectly flown ending has the glider at a fairly low speed, roughly the average speed for the task,and does not have a big pull up.
UH

Op dinsdag 21 januari 2014 14:28:50 UTC+1 schreef :
On Tuesday, January 21, 2014 7:14:15 AM UTC-5, J. Nieuwenhuize wrote:

Op maandag 20 januari 2014 21:21:11 UTC+1 schreef : On Monday, January 20, 2014 3:03:41 PM UTC-5, J. Nieuwenhuize wrote: Why not use the total height? So height (AGL) plus potential height (speed²/(2*a)) That makes ballistic pull-ups useless, allows, actually favors smooth finishes. Then set the total height rather high and substract one point per feet too low. Simply put- because this becomes a pilot and scoring nightmare. Note that each glider converts kinetic energy to potential energy differently. UH Not really; in fact they do it exactly the same way. Even an unballasted club class glider looses only a few percent (due to drag during the pull-up). Since virtually all pilots fly with a TE energy system and rely exclusively on it, I highly doubt it'd be a pilots nightmare. The ideal finish with a fixed height finish line/circle (or point substraction when too low) is fairly straightforward; fly at best MC, say 100 kts and pull up agressively, just before the finish ring. Exactly the opposite of what you'd want... A hard deck within - say - 4 miles from the finish line is a simple alternative. Get below finish height and you're scored as a land-out.



You are suggesting an alternative that requires computation in the cockpit to allow for kinetic energy and then asking the scorer to do the same. The current systems use direct measurement of one attribute (height) measured with a simple existing instrument and easily verifiable by the scorer.
If you dumb it down enough, there'll be a point where it's a simple "get up and fly as far as you can". YMMV, but the hard deck is a simple alternative, to which I can't see any major drawbacks..

The glide final scenario you describe is actaully not optimum. A perfectly flown ending has the glider at a fairly low speed, roughly the average speed for the task,and does not have a big pull up.

Yes, it is the optimum. If you fly from a given point A with a given lift to a given point B, ignoring sink or lift during the final glide, flying mac-Cready, while decreasing the altitude of point B with the potential height from the given MC gives the smalles time and thus the highest speed. Then you'd fly @ MC till you're below point B and pull up vertical. With a ground-level finish this is impossible, but flying MC until you're near the ground and coasting out in ground effect then is optimum (least time taken=highest speed)

A hard deck within - say - 4 miles from the finish line is a simple alternative. Get below finish height and you're scored as a land-out.

This is indeed a simple and better alternative. It eliminates all this worry about pilots thermaling low to get over the edge, as well as last minute pull ups. (A pull up to get over the hard deck won't work, as you will run out of energy.)

We don't have it, because you see the uproar that a simple finish cylinder is causing. Mention the words "hard deck" -- even just a doughnut at 500 feet AGL, 4 miles around the airport -- and there will be RAS apoplexy. I brought it up once, and the rest of the RC pointed out wisely that if I wanted to go get tarred and feathered that was fine, but they weren't going to join me.

Don't do big pull ups at the finish!

Once, approaching Hobbs at about 70 knots -- I was on a pretty marginal glide to the cylinder -- about 1.1 miles out a glider rose up right in front of me. He had passed me below at high speed, somehow missed the glider above him (me). Staring at the airport on final glide is common. At the moment of the pull up, I couldn't see him -- I'm above -- and he couldn't see me -- now behind his tail.

When you do a big pull up, there is no way to see who is above and behind you!

John Cochrane