Is the 200ft below Min Finish Height Rule Working?

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 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

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

Personally, I kinda like this 4 mile hard deck idea. It is simple to understand and solves a real problem. The idea of pull ups at 1 mile and 700 ft AGL is a little terrifying. The hard deck would certainly prevent that potential behavior.

On the other hand, (devil's advocate), the high points risk associated with flying out over the hard deck with low energy would result in the same "save it" circling just outside of the 4 miles hard deck "shelf" instead of 1 mile finish circle. The good news is the gliders would be slightly higher at 4 miles.

Would this hard deck be 500 AGL (penalty penalty) or 700AGL (finish height)?

Sean

On Tuesday, January 21, 2014 8:53:46 AM UTC-5, wrote:
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

A hard deck in a 4 mile radius doesn't resolve the issue, only moves the
problem further away from the airport. The only solution is a hard deck
throughout the task area - but wait... what about mountain sites, that's
OK, we will come up with a separate rule for that when we get there .

Cheers,
Luke

PS: I am not advocating a hard deck throughout the task area.. I am
just trying to demonstrate what happens when we move the responsibility
of flight safety from the PIC to the RC...



On 01/21/2014 11:50 AM, Sean F (F2) wrote:
Personally, I kinda like this 4 mile hard deck idea. It is simple to understand and solves a real problem. The idea of pull ups at 1 mile and 700 ft AGL is a little terrifying. The hard deck would certainly prevent that potential behavior.

On the other hand, (devil's advocate), the high points risk associated with flying out over the hard deck with low energy would result in the same "save it" circling just outside of the 4 miles hard deck "shelf" instead of 1 mile finish circle. The good news is the gliders would be slightly higher at 4 miles.

Would this hard deck be 500 AGL (penalty penalty) or 700AGL (finish height)?

Sean

On Tuesday, January 21, 2014 8:53:46 AM UTC-5, wrote:
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

On Tuesday, January 21, 2014 1:46:33 PM UTC-5, Luke Szczepaniak wrote:
A hard deck in a 4 mile radius doesn't resolve the issue, only moves the

problem further away from the airport.


I'm with John and Sean on this one. Simple, no need to calculate points and easy for contest management to set realistic and acceptable limits for their site. The risks associated with thermaling attempts low down are mitigated.

For the height calculation at 4 miles out, pick a glide angle that covers the gliders flying in a class, e.g. Height lost at nominal value 35:1 glide angle over 4 miles, round number 600 ft. Add minimum circuit height of let's say 600ft and the number is 1,200 ft for a 4 mile finish ring. Change the numbers up or down by changing the glide angle component and/or the minimum circuit height values, it's a contest management decision.

This is pretty much what we do for a weather safety finish, once you hit the ring the race is over and points are in the bag, no need to take any more risks and plenty of height to make a decision. If the issue is safety, what's stopping us going ahead other than the rules committee's reluctance to have their feet held to the fire. I have removed my shoes and socks, light the burners.

I can appreciate Hank Nixon’s idea that the rule should be clear and simple. I have little background in this particular issue but what I have not seen yet is the data that supports a fixed 200-foot penalty zone as opposed to some other number between the MFH and the land out. The only thing I see in the rule notes is that the 200’ value was established to accommodate instrument error.

As I understand A10.9.2.2, the CD determines the altitude at one mile from which a safe landing at the contest airport can be made (normally considered 500’ plus adjustments for other traffic, terrain etc). The rule establishes the MFH as that altitude plus 200’ and requires all pilots to finish at MFH or incur a penalty that is graduated over 200’. A finish at MFH minus 201’ is scored as a land out, thereby costing as much as 400 points.

If the goal of the rule is to prevent low-save attempts near the airport, why not increase the “penalty-zone width”, (my term) from the current 200’ to say, for example, 500’ and spread the penalty points out over the 500’. If most pilots start the final glide with MFH + glide alt required + 500 margin, then the FG would have to degrade to the point that the pilot suffers a loss of an extra 1000’ before going below the land-out altitude at 1 mile.

If this rule were implemented for the 2014 season, there might well be an increase in finish penalties but there should be a marked decrease in low-save attempts on FG or land-out attempts resulting from them. Following John Cochran’s point, I expect that most pilots would accept a small penalty rather than attempt a risky save. If my expectations prove to be supported by future data analysis, then the administrative land-out part of the rule might be rendered obsolete.

The other point I would make is that even a small finish penalty (FP) collected many times will significantly reduce a pilot’s competitive standing. Eventually, even the slow-thinking racers will figure out that they are better off coming in a bit high than a bit low.

Seems to me that simply increasing the size of the “penalty zone” from 200’ to a larger value, say 500’, satisfies everyone. It is simple and clear, easy to implement, increases safety, and reduces the incentive to attempt a low save near the airport.

BZ

On Tuesday, January 21, 2014 2:53:44 PM UTC-5, Bravo Zulu wrote:
I can appreciate Hank Nixon’s idea that the rule should be clear and simple. I have little background in this particular issue but what I have not seen yet is the data that supports a fixed 200-foot penalty zone as opposed to some other number between the MFH and the land out. The only thing I see in the rule notes is that the 200’ value was established to accommodate instrument error. As I understand A10.9.2.2, the CD determines the altitude at one mile from which a safe landing at the contest airport can be made (normally considered 500’ plus adjustments for other traffic, terrain etc). The rule establishes the MFH as that altitude plus 200’ and requires all pilots to finish at MFH or incur a penalty that is graduated over 200’. A finish at MFH minus 201’ is scored as a land out, thereby costing as much as 400 points. If the goal of the rule is to prevent low-save attempts near the airport, why not increase the “penalty-zone width”, (my term) from the current 200’ to say, for example, 500’ and spread the penalty points out over the 500’. If most pilots start the final glide with MFH + glide alt required + 500 margin, then the FG would have to degrade to the point that the pilot suffers a loss of an extra 1000’ before going below the land-out altitude at 1 mile. If this rule were implemented for the 2014 season, there might well be an increase in finish penalties but there should be a marked decrease in low-save attempts on FG or land-out attempts resulting from them. Following John Cochran’s point, I expect that most pilots would accept a small penalty rather than attempt a risky save. If my expectations prove to be supported by future data analysis, then the administrative land-out part of the rule might be rendered obsolete. The other point I would make is that even a small finish penalty (FP) collected many times will significantly reduce a pilot’s competitive standing. Eventually, even the slow-thinking racers will figure out that they are better off coming in a bit high than a bit low. Seems to me that simply increasing the size of the “penalty zone” from 200’ to a larger value, say 500’, satisfies everyone. It is simple and clear, easy to implement, increases safety, and reduces the incentive to attempt a low save near the airport. BZ

I'm unclear by what BZ describes whether he is suggesting raising the top(1000 ft finish with 500 ft landout threshold, or lowering the bottom. Clearly the latter is less safe.
The 2014 rules changes reflect no changes in finish rules or scoring.
This general topic, not focused on this one sub set of the issue, was polled in 2013. One option described was a larger range over which score reduction might occur. Given no poll mandate for quich change, and mindful of the effect that changes have, the RC, wisely in my view, elected to stand pat for now.
The issue of pilots circling up tp avoid a land out score seems, to me, to be small compared to the overall safety benefit of the rules as currently used.
Sean raised this as a useful discussion point. Maybe some folks will understand a bit more about this now.
FWIW
UH