Hi Terry (and congratulations on your IGC role, and work winning Worlds for Australia)

The handicap system was devised by Peter Rigby of the Wollongong Gliding Club, and more recently maintained by a committee chaired by Graham Brown of Bathurst SC. In essence, the committee agree on a polar for each glider, then use it to predict theoretical cross-country speed on a closed circuit task in nil wind, on a day when the thermals are all a nominal "Standard Australian Thermal" of a given diameter and lift cross-section. It is a similar system to the BGA one but our thermal is bigger and stronger than theirs!! :-))

We now use two sets of handicaps, one for ballasted gliders and the other without ballast (i.e. dry) for club and sports class comps. There is a glider type (currently the LS4) that is assigned a handicap of 100.0% and other types are scaled relative to this one to produce the final handicap figure.

The Murray Evans system did almost a reverse of this process - it worked from the achieved speed to input to the polar curve and determine the actual thermal strength used - scoring could then be done to award the daily maximum points to the pilot who used the best thermals (or who used streets to best advantage or cruised in rising air to the greatest extent). This has the advantage of automatically adjusting for wind on the day, the greatest failing of the standard handicap. In the UK nowadays, or last time I looked, they actually change the handicaps on a daily basis depending on the observed wind for the task, so higher performance gliders do not get an inbuilt advantage on windy days and lower performance gliders are not penalised by the wind. However, this still does not overcome Peter R's problem that to complete a fixed task, he has to fly for a longer time and thus risk having to use weaker lift than his competitors who only use the stronger past of the day. Hence the idea of the variable task which developed into our current form of AAT.

So some pilots spend a lot of time, effort and money working on their glider to try and make it perform better than others of the same type, and handicappers invent factors for winglets, turbulators and actual wing loadings of lighter pilots flying unballasted - but nobody yet regularly uses a reference thermal that reflects the actual conditions on the day, or the fact that some sites experience consistently better thermals than others.

Pilot-based handicaps sounds more like golf than flying!

Wombat


On 7/03/2013 11:06 PM, Terry wrote:
The ME formula was used for many years, but it was used to compare results across classes for team selection, not handicaps. ME would apply the formula to produce a team solution and then some "wise" heads would critique and then ME would "adjust" the factors and produce a new set of results. Eventually an answer was agreed. The most subjective objective process.

Handicaps were formulated by another member (? Brown?) who spent a lot of personal time reviewing polar curves and calculating thermal characteristics to calculate the "right" handicap. The concept was good but Unfortunately, the polar curve data was from many sources and therefore no consistency. The first club class I went to the pilots spent the whole two weeks arguing about handicaps.

We then invited another group of wise heads to use their experience and invent some handicaps. Since that time, there have been very few issues with handicaps. It is not an exact science.

At Gawler we now use Pilot handicaps also , which is even less scientific, but good fun. A little retrospective adjustment resolves any errors.

Terry

Sent from my iPhone

On 07/03/2013, at 8:10 PM, <gstev...@bigpond.com <mailto:gstev...@bigpond.com>> wrote:

Peter,
That is an interesting suggestion! I wonder if it could be practically (and fairly), done? Re "poor" task setting, I tend to think that your objection 'having to start early/finish late" is actually *as a general principle*, just the opposite - at a National level and probably a State level too, this is what good tasking should be all about! In general, the task setting at most competitions, on most reasonably soarable days, is far too conservative. {Everybody, please carefully note those two provisos - "most" & "reasonably"!} Having said that, I tend to agree with your last paragraph, which then gets back to the question I raised in *my* first paragraph above. The points noted by Matthew Scutter, in his email below, are all reasonable too. Emilis Prelgauskas in a recent posting on this site, talked (amongst other things), about some of the problems facing the gliding movement in this country, including a gradual loss of knowledge held collectively by the membership, and knowledge (mostly), lost to the current Board and those administrating the GFA system. Once upon a time - I think it was just around the time of the introduction of computers into gliding scoring - a guy called Murray Evans (Murray-Evans?), came up with a system that related everybody's performance back to their glider polar, and the results for the day were then "corrected". The system was tried once, and promptly abandoned, as being unworkable - which was fair enough *_at the time_*. The first and possibly major problem then, was obtaining realistic polars, for the gliders competing. Number crunching (laughable today), was also a problem, as I recall. In my view, it might now prove profitable to revisit the *_principles_* of the ME concept, and check their workability in the current hi-tek environment. *Ann Woolf - given the tremendous (mind boggling?) - work that you have done on compiling the electronic AG data base - could I please call upon you to put the article(s?), that appeared in /Australian Gliding/, on this web site, for the perusal and comment of a latter generation of glider pilots?*
**
Gary
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