A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

US club class definition



 
 
Thread Tools Display Modes
  #21  
Old February 1st 17, 10:44 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 317
Default US club class definition

Interesting, I have owned my Ventus B for 20 years and although I am not competitive with current production models in FAI class comps, I have only entered FAI 15 meter comps. And always getting my butt handed to me 😁 Being included in club class I would consider competing in that class if for no other reason to see if it's me or the ship, even though I already know that answer. Now if only participation in the West would rise to the point that we could have Club class contests.
  #22  
Old February 2nd 17, 12:00 AM posted to rec.aviation.soaring
Tony[_5_]
external usenet poster
 
Posts: 1,965
Default US club class definition

On Wednesday, February 1, 2017 at 3:44:39 PM UTC-6, wrote:
Interesting, I have owned my Ventus B for 20 years and although I am not competitive with current production models in FAI class comps, I have only entered FAI 15 meter comps. And always getting my butt handed to me 😁 Being included in club class I would consider competing in that class if for no other reason to see if it's me or the ship, even though I already know that answer. Now if only participation in the West would rise to the point that we could have Club class contests.


Hobbs this summer!
  #23  
Old February 2nd 17, 12:55 AM posted to rec.aviation.soaring
Paul T[_4_]
external usenet poster
 
Posts: 259
Default US club class definition

What is needed internationally is a two class Club Class A and B - for
higher and lower performing 'obsolescent' ships - would be far better
than the ill thought out 13.5 m class - which is now producing mini-
15m class ships, costing 100k or more.
Maybe something like Ka6e to Asw19b -class A, LS4 to Ventus/LS6 -
class B ?

Don't see why it should be a span limited class either. Should be based
on handicap. - let in the Kestrels, Open Cirri ect.

Ka6e's, SHK's and Open Cirrus's have all flown in UK Club Class
Nationals before.


  #24  
Old February 2nd 17, 05:57 AM posted to rec.aviation.soaring
Sierra Whiskey
external usenet poster
 
Posts: 38
Default US club class definition


I like the explanation of "Club Class" on the FAI site:
"The Club Class arose to provide international level competition in club-type gliders for the large number of talented pilots who could not aspire to owning an expensive modern glider of their own. It has kept demand high for a number of older but still very valid designs."

Of course the term "Expensive" is relative, but the current US Club Class list spans roughly $10,000-$80,000 where the FAI list is much narrower.

My Two Cents:
If the handicapping of gliders were quantifiable through the use of a formula that accounted for the performance of the glider in order to actually level the playing field of the aircraft and allow for a measure of the pilot then the introduction of modern gliders to the class would make more sense. Correct me if I am wrong, but for over a decade the US handicap system has been more of an arbitrary assignment than a calculation.

I look at the Std. Cirrus compared to the LS-8. Their US Handicaps respectively are 1.0 and 0.915. To me this would imply that the LS-8 is 8.5% "better" than a Standard Cirrus. (Better is not the best descriptor, but is meant to be a summary of glide performance and speed).

Lets assume that the two gliders mentioned above are flying at Best L/D.
LS-8: 43:1 at about 50 kts
Std. Cirrus: 36.5:1 at 50 kts
I calculate the difference in performance by looking at a multiple of the GR*V_(L/D). Since in this case the V_(L/D) is the same we can omit them, and just compute (36.5/43) which gives 0.849.

The numbers above are a bit crude because they are pulled from various sources online. Even the LS-8 data is "Calculated" and the tested data is slightly different. Looking at it from other sources:
LS-8: 43:1 at about 50 kts
Std. Cirrus: 38:1 at 50 kts
This still gives the LS-8 an advantage of 0.884.

In a final "base" example I will use some extreme numbers, degrading the performance of the LS-8, and exaggerating the performance of the Standard Cirrus:
LS-8: 42:1 at about 50 kts
Std. Cirrus: 38.5:1 at 50 kts
We finally arrive at an advantage of 0.917! (I take this as a "Factory New Std. Cirrus" flying against a "Buggy LS-8 without Gap Seals"?)

The above examples would be great if we flew contests while flying at Best L/D speed over three hour courses of 150 miles. The fact of the matter is we are frequently pushing MacCreedy "2" speeds on four hour courses that exceed 240 miles. (Let's compare the performance at 60 kts)

Since I don't have either of these factory polar curves to use, again, I am coming up with crude numbers, but I still think they speak volumes. These are a comparison of the L/D at a constant sink rate (2 m/s):
LS-8: 24:1 at about 92 kts (92*24=2,208)
Std. Cirrus: 22:1 at 86 kts (22*86=1,892)
Now we have a performance comparison at a more representative cruise speed in competition with a yield of 0.857 in favor of the LS-8. This means at a target MacCreedy speed I would expect the LS-8 to perform roughly 14% more efficient than the Standard Cirrus assuming the exact same pilot in the exact same point (Position/Altitude). This seems to be quite far from the 8.5% advantage given by the current Handicap List.

Does anyone have any information on how the current US handicaps are derived? I would really like to see what performance numbers were used to calculate the level playing field numbers that we currently use.

Thank you for any help or pointing me in the right direction! Only one of my calculations even come close, and it seems to be an extreme example!

  #25  
Old February 2nd 17, 07:00 AM posted to rec.aviation.soaring
Bruce Hoult
external usenet poster
 
Posts: 961
Default US club class definition

On Thursday, February 2, 2017 at 7:58:01 AM UTC+3, Sierra Whiskey wrote:
I like the explanation of "Club Class" on the FAI site:
"The Club Class arose to provide international level competition in club-type gliders for the large number of talented pilots who could not aspire to owning an expensive modern glider of their own. It has kept demand high for a number of older but still very valid designs."

Of course the term "Expensive" is relative, but the current US Club Class list spans roughly $10,000-$80,000 where the FAI list is much narrower.

My Two Cents:
If the handicapping of gliders were quantifiable through the use of a formula that accounted for the performance of the glider in order to actually level the playing field of the aircraft and allow for a measure of the pilot then the introduction of modern gliders to the class would make more sense. Correct me if I am wrong, but for over a decade the US handicap system has been more of an arbitrary assignment than a calculation.

I look at the Std. Cirrus compared to the LS-8. Their US Handicaps respectively are 1.0 and 0.915. To me this would imply that the LS-8 is 8.5% "better" than a Standard Cirrus. (Better is not the best descriptor, but is meant to be a summary of glide performance and speed).

Lets assume that the two gliders mentioned above are flying at Best L/D.
LS-8: 43:1 at about 50 kts
Std. Cirrus: 36.5:1 at 50 kts
I calculate the difference in performance by looking at a multiple of the GR*V_(L/D). Since in this case the V_(L/D) is the same we can omit them, and just compute (36.5/43) which gives 0.849.

The numbers above are a bit crude because they are pulled from various sources online. Even the LS-8 data is "Calculated" and the tested data is slightly different. Looking at it from other sources:
LS-8: 43:1 at about 50 kts
Std. Cirrus: 38:1 at 50 kts
This still gives the LS-8 an advantage of 0.884.

In a final "base" example I will use some extreme numbers, degrading the performance of the LS-8, and exaggerating the performance of the Standard Cirrus:
LS-8: 42:1 at about 50 kts
Std. Cirrus: 38.5:1 at 50 kts
We finally arrive at an advantage of 0.917! (I take this as a "Factory New Std. Cirrus" flying against a "Buggy LS-8 without Gap Seals"?)

The above examples would be great if we flew contests while flying at Best L/D speed over three hour courses of 150 miles. The fact of the matter is we are frequently pushing MacCreedy "2" speeds on four hour courses that exceed 240 miles. (Let's compare the performance at 60 kts)

Since I don't have either of these factory polar curves to use, again, I am coming up with crude numbers, but I still think they speak volumes. These are a comparison of the L/D at a constant sink rate (2 m/s):
LS-8: 24:1 at about 92 kts (92*24=2,208)
Std. Cirrus: 22:1 at 86 kts (22*86=1,892)
Now we have a performance comparison at a more representative cruise speed in competition with a yield of 0.857 in favor of the LS-8. This means at a target MacCreedy speed I would expect the LS-8 to perform roughly 14% more efficient than the Standard Cirrus assuming the exact same pilot in the exact same point (Position/Altitude). This seems to be quite far from the 8.5% advantage given by the current Handicap List.

Does anyone have any information on how the current US handicaps are derived? I would really like to see what performance numbers were used to calculate the level playing field numbers that we currently use.

Thank you for any help or pointing me in the right direction! Only one of my calculations even come close, and it seems to be an extreme example!


BGA has them at 90 and 100, so 10% or 11.1% different depending on which way you look at it.

The problem with these is one number can't apply across all conditions, especially with gliders so far apart in performance and generation.

On strong days, the LS8 is obviously going to run away into the distance and win a three hour race by far more than twenty minutes.

But on a weak day where you can barely stay aloft and the thermals are weak and narrow? It might be a lot closer, maybe even close to equal.

There probably exist days when a Ka8 can beat an LS8. Not often, mind.
  #26  
Old February 2nd 17, 02:35 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 61
Default US club class definition

Regarding modern standard class gliders such as LS8 in Club Class, my opinion is that given an appropriate handicap factor, they may be perfectly acceptable provided ballasting is prohibited (as it is in the FAI definition of the class).
FAI leaves a lot of freedom about national rules for the gliders eligible in club class events (excluding those sanctioned by FAI at world or continental level).
In Italy we strictly apply the "IGC club class handicap list" which includes small adjustments for wingloading (think: Discus bT, PIK20E). The actual handicap for a single sailplane after the adjustments shall not exceed the max. accepted hcap factor indicated in the class definition.

Aldo Cernezzi

  #27  
Old February 2nd 17, 06:49 PM posted to rec.aviation.soaring
Tango Eight
external usenet poster
 
Posts: 962
Default US club class definition

On Wednesday, February 1, 2017 at 11:58:01 PM UTC-5, Sierra Whiskey wrote:
[...]
My Two Cents:
If the handicapping of gliders were quantifiable through the use of a formula that accounted for the performance of the glider in order to actually level the playing field of the aircraft and allow for a measure of the pilot then the introduction of modern gliders to the class would make more sense. Correct me if I am wrong, but for over a decade the US handicap system has been more of an arbitrary assignment than a calculation.

I look at the Std. Cirrus compared to the LS-8. Their US Handicaps respectively are 1.0 and 0.915. To me this would imply that the LS-8 is 8.5% "better" than a Standard Cirrus. (Better is not the best descriptor, but is meant to be a summary of glide performance and speed).

Lets assume that the two gliders mentioned above are flying at Best L/D.
LS-8: 43:1 at about 50 kts
Std. Cirrus: 36.5:1 at 50 kts
I calculate the difference in performance by looking at a multiple of the GR*V_(L/D). Since in this case the V_(L/D) is the same we can omit them, and just compute (36.5/43) which gives 0.849.

The numbers above are a bit crude because they are pulled from various sources online. Even the LS-8 data is "Calculated" and the tested data is slightly different. Looking at it from other sources:
LS-8: 43:1 at about 50 kts
Std. Cirrus: 38:1 at 50 kts
This still gives the LS-8 an advantage of 0.884.

In a final "base" example I will use some extreme numbers, degrading the performance of the LS-8, and exaggerating the performance of the Standard Cirrus:
LS-8: 42:1 at about 50 kts
Std. Cirrus: 38.5:1 at 50 kts
We finally arrive at an advantage of 0.917! (I take this as a "Factory New Std. Cirrus" flying against a "Buggy LS-8 without Gap Seals"?)

The above examples would be great if we flew contests while flying at Best L/D speed over three hour courses of 150 miles. The fact of the matter is we are frequently pushing MacCreedy "2" speeds on four hour courses that exceed 240 miles. (Let's compare the performance at 60 kts)

Since I don't have either of these factory polar curves to use, again, I am coming up with crude numbers, but I still think they speak volumes. These are a comparison of the L/D at a constant sink rate (2 m/s):
LS-8: 24:1 at about 92 kts (92*24=2,208)
Std. Cirrus: 22:1 at 86 kts (22*86=1,892)
Now we have a performance comparison at a more representative cruise speed in competition with a yield of 0.857 in favor of the LS-8. This means at a target MacCreedy speed I would expect the LS-8 to perform roughly 14% more efficient than the Standard Cirrus assuming the exact same pilot in the exact same point (Position/Altitude). This seems to be quite far from the 8.5% advantage given by the current Handicap List.


What phase of competition flight, often comprising nearly half the total time on course, have you left out? How much distance and speed is made during this phase? How different are the LS-8 and Std Cirrus during this phase? Does this affect your analysis at all :-)?

best,
Evan
  #28  
Old February 2nd 17, 10:49 PM posted to rec.aviation.soaring
Sierra Whiskey
external usenet poster
 
Posts: 38
Default US club class definition

No argument there, it is difficult to quantify the climb performance utilizing upward moving air. This would take some evaluation of the wing loading and sink rate at thermaling speeds.

That in mind, the analysis of speed and sink comparisons does indicate that if those two gliders left the same thermal at the same altitude and at the same time, the lower performing glider would arrive at the same next thermal lower and after the higher performing glider. Any delta in the climb performance (if one could be accurately calculated) would be negated by the point of arrival in the next thermal. So in a way the climb performance of the glider is accounted for in the calculation, probably as an under-estimate..

The above is probably why it is also so difficult to handicap variable ballasted gliders!

A while back I developed a plan to create a variable handicap where a Contest Director (with the help of the Weather Adviser) would declare three components to the race: Task, MacCready Value for the day, and a wind value for the day. Each handicap for the day would be based on the sink rate of each glider at the given MC and Headwind Values defined for the day. The idea was to level the playing field between a PW-5 and an ASG-29 across the different soaring conditions.

Examples:
1) Strong Lift- ASG-29 will cruise much further and more efficiently than a PW-5
2) Weak Lift- PW-5 will climb and stay aloft much easier.
3) Heavy Wind- ASG-29 has much better penetration into a strong headwind.

The reality is that the development of this system would take a significant amount of time due to a lack of high resolution data for glide performance across the spectrum of aircraft. Though the solution is difficult to design and implement, it would provide a better system to handicap gliders based on the soaring conditions, and not just a single performance value. The negative impact of this system is the requirement for rules protecting the CD from making a less than desirable call on the day values, and would introduce some new soaring strategy to optimize the performance of each aircraft based on the variable handicap for the given conditions.

This all came about while I was trying to determine how each glider's handicap is calculated. Unfortunately I am still unclear on how that happens.

  #29  
Old February 3rd 17, 02:53 AM posted to rec.aviation.soaring
Andrzej Kobus
external usenet poster
 
Posts: 585
Default US club class definition

On Thursday, February 2, 2017 at 4:49:34 PM UTC-5, Sierra Whiskey wrote:
No argument there, it is difficult to quantify the climb performance utilizing upward moving air. This would take some evaluation of the wing loading and sink rate at thermaling speeds.

That in mind, the analysis of speed and sink comparisons does indicate that if those two gliders left the same thermal at the same altitude and at the same time, the lower performing glider would arrive at the same next thermal lower and after the higher performing glider. Any delta in the climb performance (if one could be accurately calculated) would be negated by the point of arrival in the next thermal. So in a way the climb performance of the glider is accounted for in the calculation, probably as an under-estimate.

The above is probably why it is also so difficult to handicap variable ballasted gliders!

A while back I developed a plan to create a variable handicap where a Contest Director (with the help of the Weather Adviser) would declare three components to the race: Task, MacCready Value for the day, and a wind value for the day. Each handicap for the day would be based on the sink rate of each glider at the given MC and Headwind Values defined for the day. The idea was to level the playing field between a PW-5 and an ASG-29 across the different soaring conditions.

Examples:
1) Strong Lift- ASG-29 will cruise much further and more efficiently than a PW-5
2) Weak Lift- PW-5 will climb and stay aloft much easier.
3) Heavy Wind- ASG-29 has much better penetration into a strong headwind.

The reality is that the development of this system would take a significant amount of time due to a lack of high resolution data for glide performance across the spectrum of aircraft. Though the solution is difficult to design and implement, it would provide a better system to handicap gliders based on the soaring conditions, and not just a single performance value. The negative impact of this system is the requirement for rules protecting the CD from making a less than desirable call on the day values, and would introduce some new soaring strategy to optimize the performance of each aircraft based on the variable handicap for the given conditions.

This all came about while I was trying to determine how each glider's handicap is calculated. Unfortunately I am still unclear on how that happens.


In regards to development of the system. You need to employ analytics to solve this problem. OLC data is all you need to find the levers.
  #30  
Old February 3rd 17, 06:36 AM posted to rec.aviation.soaring
SoaringXCellence
external usenet poster
 
Posts: 385
Default US club class definition

I recall when Carl Herold started the handicapping system for the US in 1972 (or about that time). He did not use the manufacturer numbers for the ship but rather the performance achieved in contests (back in those days it was racing to specific turnpoints which put more of the glider on the same course, in similar air).

He discounted the handicap when the glider was flown by an experienced (high scoring competitor) and increased the handicap if the model was doing well in the hands of new competitors.

I don't know what the "calculations" were, but in the beginning it was a rough cut which was refined year after year through the early '80's (I think) when others took over the task of assigning handicaps. I know that if a particular design was not commonly flown in competition the result was less useful.


I'm sure someone will correct me for the things I've forgotten, but that is the way I remember Carl explaining it.

Mike
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sports class/ club class differences? Jonathan St. Cloud Soaring 1 June 20th 15 04:16 PM
Potential Club Class (US Sports Class) World Team Selection Policy Changes John Godfrey (QT)[_2_] Soaring 84 September 27th 10 08:03 PM
Potential Club Class (US Sports Class) World Team SelectionPolicy Changes JS Soaring 4 September 22nd 10 04:55 PM
Potential Club Class (US Sports Class) World Team SelectionPolicy Changes Andy[_10_] Soaring 0 September 19th 10 10:33 PM
UK Open Class and Club Class Nationals - Lasham Steve Dutton Soaring 0 August 6th 03 10:07 PM


All times are GMT +1. The time now is 11:17 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright Š2004-2024 AviationBanter.
The comments are property of their posters.