Is the 200ft below Min Finish Height Rule Working?

On Tuesday, January 21, 2014 3:41:35 PM UTC-8, Bravo Zulu wrote:

"I read that is the minimum altitude to avoid a land out is “normally 500’ with a “penalty zone” of 200’ more. I am simply suggesting that the rule could be improved by adding 300’ to the fixed 200’ as a “penalty zone”. That would preserve the accommodation for instrument error and add an additional measure of safety. It would also make the accumulation of penalty points for a slightly low finish more gradual. My suggestion of a 500’ “penalty zone” was just an example. The RC could pick another number if it were more efficacious. The bigger it is the more gradual the accumulation of penalty points would be. The effect is that for a small error in arrival height there is less incentive to attempt a low save. Finding oneself 200’ lower that intended is more likely than being 500’ lower."


Deep breath. Lots to discuss here.

In the interest of exposing some of the richness of the issues for those of you who are interested enough to dig into the actual details that inform these decisions, here we go.

There are three main objectives for setting rules around finish height and then a bunch of considerations. In rough order of priority:

1) The top objective is to make sure that pilots set up enough altitude buffer to get home without hitting the dirt under most scenarios of unexpected sink, headwind, etc. A decent MFH does this pretty well so long as it includes a penalty that costs more than the speed points lost from stopping to climb in a weak thermal. (Otherwise pilots gain points by ignoring thermals below the break-even climb rate for the penalty gradient). This is the highest order pilot decision - setting up the glide is at the top of the final glide decision chain. The penalty is fundamental - without a penalty structure MFH is practically meaningless. If you want to have all pilots set a 1000' arrival you need around 100-200 points per 1000' at stake to create an incentive in favor of climbing in a weak thermal rather than pressing on.

2) A related, but separate, second objective is to not create a points temptation to go for the finish cylinder at a height from which you cannot safely make the airport - instead of picking a decent field while you have a little altitude. This is mostly a "glide gone wrong" or "glide that was never right" scenario and is a totally different pilot decision from #1. This minimum safe altitude is, as has been pointed out, around 400-500' a mile out, depending on the airport configuration. Therefore, the penalty for 500' or below needs to be around 400 points to get rid of the points incentive to press on. That means you need to spread 400 points of penalty over the difference between MFH and 500 feet. That's 0.8 points per foot for a MFH of 1000'. If you set a 700' MFH you need to use 2.0 points per foot and if you set a 501' MFH it's 400 points per foot.

3) A third objective is to not encourage pilots to thermal low. This objective is subordinate to the other two in part because it conflicts with the other two and because it's pretty clear that having everyone finish at zero feet is not a good solution to not having people thermal low. Any MFH with a penalty will yield some situations where a pilot would prefer no penalty to any penalty and will try to climb up to get out of the penalty zone. The old rule, BTW, also had this feature only with fewer points at stake. It is not clear how many pilots would reject a climb to avoid a 50 or 100 point penalty but would take the same climb when the penalty is 400 points, maybe some, but experience indicates that many pilots would take a climb at 500' for to save a small number of points.

Then there are additional considerations that shape the final solution. People hate complexity so having a variable penalty based on MFH was set aside as was restricting the MFH to 1000' because some sites need MFH lower mostly to accommodate ridge tasks. One to two points per foot was viewed by many pilots as draconian small misses so a more gentle penalty was put in place for the first 200'.

After all these additional considerations you are left with basically no room for further graduation of the penalty for MFH700' - and a pretty steep gradient even for MFH=1000'.

Also worth pointing out, the old rule only addressed the first objective, not the second or third. The new rule addresses the first and second, but not the third. Adding a 500' hard deck for 5+ miles around the finish (either to the current rule or some steeply graduated variation) would address the first two plus mitigate the third quite a bit because you'd push the problem out so far that any pilot who is facing it is already in a landout situation. Not sure the pilot community is supportive of a hard deck, even a small one around the finish, but I'd be curious to know if it's viewed as worth it in order to reduce the low thermalling temptation.

9B

On Tuesday, January 21, 2014 5:17:10 PM UTC-8, wrote:

Also worth pointing out, the old rule only addressed the first objective, not the second or third. The new rule addresses the first and second, but not the third. Adding a 500' hard deck for 5+ miles around the finish (either to the current rule or some steeply graduated variation) would address the first two plus mitigate the third quite a bit because you'd push the problem out so far that any pilot who is facing it is already in a landout situation. Not sure the pilot community is supportive of a hard deck, even a small one around the finish, but I'd be curious to know if it's viewed as worth it in order to reduce the low thermalling temptation.


A correction - the 5 mi/500' hard deck would not necessarily require a steeply graduated penalty above 500'. You can allow a modest penalty gradient for the entire distance between 500' and MFH, not just the first 200'.

You probably want the hard deck out at least 5 miles so even the most optimistic pilot who reaches the top edge of the deck will already know (s)he's not making the airport.

9B

Unfortunately the rules committee has failed to reverse a very unpopular rule change. It was clear by the overwhelming negative vote at 15M nats that the pilots don't like it.

Why not make a simple rule that gives a penalty for a finish lower than the official finish height and leave the rest alone.

How about this

1 mile finish ring at 500 Agl.

You miss it you get a 25 point penalty and -0.4 points per foot.

This would give a maximum of 225 points penalty. It gives plenty of incentive to stop and find lift.

On Tuesday, January 21, 2014 7:22:55 PM UTC-8, Tim Taylor wrote:
How about this

1 mile finish ring at 500 Agl.

You miss it you get a 25 point penalty and -0.4 points per foot.

This would give a maximum of 225 points penalty. It gives plenty of incentive to stop and find lift.

Hi Tim,

Your proposal addresses the first objective of a minimum finish height/penalty, but not the second or third (see my earlier post). Maybe you are okay with that. The pilot survey (and this thread) reveals a wide range of views and preferences on the subject. There very well may be a better alternative out there, but with a bifurcated pilot population it will need to be something outside the box to bridge the gaps in what the community would like. This discussion has exposed some potential new elements and preferences that I personally think might be worthy of further development.

Andy

Could we please just raise the finish height to 2000 feet and get it over with? i'll just do contest style finishes when i'm not at contests.

having made my sarcastic remark, I do appreciate the efforts to make this sport safer. the problem is you cannot prevent accidents universally, this is aviation and racing combined. Instead we need to encourage pilots to make safe decisions rather than trying to protect everyone by implementing rules.

my two cents.

2000 ft is a little high ;-), but (based on the discussion within this thread) we definitely need to consider moving MFH and any hard deck up to just above a mutually agreed "safe circling altitude." This minimum acceptable safe circling altitude is the key. I think we all agree that any finish height rule is absolutely going to cause a certain subset of pilots to instinctively try and save their points just outside the distance barrier and just below the penalty altitude.

1200 feet AGL is probably the right MFH (with graduated penalties down to 1000 AGL) as a stall spin is PROBABLY recoverable from 800 - 900 feet in most gliders. This is where the gliders "caught" by this rule will be "doing their dance!"

At 18 meter nationals last summer (due to the nature of the finishes and the lack of acceptable landing options surrounding the airfield) the MFH was moved up mid contest. There was luke warm debate although the CD managed the discussion very eloquently. Ultimately, a vote was taken and the result was in favor of raising the MFH. I think it was moved from 700 to 800 AGL.. It might have been higher. I do not remember.

1200 ft, is only 400 above 18m Nationals last summer. Clearly, it offers a greater cushion should the unthinkable happen and someone spins...

Of course, the other alternative is simply to remove this rule altogether and just allow the pilots to make their own choices. It is a quite a pickle....

Personally, I am open to both options. What I don't really like is the current rule which results in gliders circling below 700 ft and in some cases below 500 just prior to arrival at the finish location.

Sean
F2

On Wednesday, January 22, 2014 9:18:32 AM UTC-5, Andrew Brayer wrote:
Could we please just raise the finish height to 2000 feet and get it over with? i'll just do contest style finishes when i'm not at contests.



having made my sarcastic remark, I do appreciate the efforts to make this sport safer. the problem is you cannot prevent accidents universally, this is aviation and racing combined. Instead we need to encourage pilots to make safe decisions rather than trying to protect everyone by implementing rules.



my two cents.

PWhat I don't really like is the current rule which results in gliders circling below 700 ft and in some cases below 500 just prior to arrival at the finish location.


What I don't get is why circling at 500 feet to make it over the finish line is a qualitatively different thing than circling at 500 feet to avoid a landout. If you want a hard deck, ask for a hard deck.

A hard deck is available by waiver if any CD wants to try it, BTW. Just ask. A hard deck donut is available by waiver if you want to try that too. For higher finishes, just ask the CD.

John Cochrane

Well we've certainly come a long way from the "plea for a 500' finish".

Guys: it's a MINIMUM finish height. If you feel you need 1200 agl to be safe (there are days like that at some sites), you plan accordingly.

The story from 18s last year is bizarre. Anyone so focused on hitting MFT at minimum speed that they subsequently discover their airport arrival, pattern, sequencing and landing is compromised is just being irresponsible. If your airport arrival planning suggests higher than MFH, you just better damned well do it. Absent a really silly high MFH, these are concurrent, not serial tasks.

Evan Ludeman / T8

Of course, the other alternative is simply to remove this rule altogether and just allow the pilots to make their own choices. It is a quite a pickle...



Personally, I am open to both options. What I don't really like is the current rule which results in gliders circling below 700 ft and in some cases below 500 just prior to arrival at the finish location.



Sean


I have to agree. and anyone who circles BELOW 500 when they're that close to the field is a schmuck.

On Wednesday, January 22, 2014 11:48:44 AM UTC-5, Sean F (F2) wrote:
2000 ft is a little high ;-), but (based on the discussion within this thread) we definitely need to consider moving MFH and any hard deck up to just above a mutually agreed "safe circling altitude." This minimum acceptable safe circling altitude is the key. I think we all agree that any finish height rule is absolutely going to cause a certain subset of pilots to instinctively try and save their points just outside the distance barrier and just below the penalty altitude. 1200 feet AGL is probably the right MFH (with graduated penalties down to 1000 AGL) as a stall spin is PROBABLY recoverable from 800 - 900 feet in most gliders. This is where the gliders "caught" by this rule will be "doing their dance!" At 18 meter nationals last summer (due to the nature of the finishes and the lack of acceptable landing options surrounding the airfield) the MFH was moved up mid contest. There was luke warm debate although the CD managed the discussion very eloquently. Ultimately, a vote was taken and the result was in favor of raising the MFH. I think it was moved from 700 to 800 AGL. It might have been higher. I do not remember. 1200 ft, is only 400 above 18m Nationals last summer. Clearly, it offers a greater cushion should the unthinkable happen and someone spins... Of course, the other alternative is simply to remove this rule altogether and just allow the pilots to make their own choices. It is a quite a pickle... Personally, I am open to both options. What I don't really like is the current rule which results in gliders circling below 700 ft and in some cases below 500 just prior to arrival at the finish location. Sean F2 On Wednesday, January 22, 2014 9:18:32 AM UTC-5, Andrew Brayer wrote: Could we please just raise the finish height to 2000 feet and get it over with? i'll just do contest style finishes when i'm not at contests. having made my sarcastic remark, I do appreciate the efforts to make this sport safer. the problem is you cannot prevent accidents universally, this is aviation and racing combined. Instead we need to encourage pilots to make safe decisions rather than trying to protect everyone by implementing rules. my two cents.

I've flown a few contests, something more than 30, since the finish cylinder, in various forms, has been in place. I have never seen anyone trying to circle up to finish height. Obviously there may be a few cases where this happens. My view is that it makes little sense to try to solve issues that occur quite rarely.
Other considerations should include the likely actions after finishing. When one finishes at about 700 feet, the height is about right to enter the pattern and we can expect most pilots to do so pretty mich immediately. We then know where to expect the other traffic to be and recovery is usually orderly.
Raise the height by several hundred feet and now everyone will need to work out a path to get down to pattern height. This introduces another factor we all have to cope with as different pilots do their own way of letting down and entering the pattern.
With the commonly used 700 foot finish, I almost always position myself when finishing so I can directly enter the pattern and land. I note that most others do the same thing. I think it works pretty well.
Also worth noting is that tactically it almost never makes sense to try to circle up to try to reduce the penalty for finishing a bit below the finish height. At about 5 pts/ minute in Nationals(8/minute in regioals),the time used pretty quickly offsets the 40 points lost for a 200 foot low arrival..
UH