Race

The VSA Races

Page revised: 12/12/2017

We had a series of glider races every season here at Williams for an eleven year period (from 2004 to 2015).  It was always popular and was enjoyed by many.   The series was suspended during the 2016 soaring season for no reason in particular, other than it was a period of transition for many glider pilots, as well as a time of additional upgrades to the facilities of Williams Soaring Center.  The annual VSA Race Series resumed in 2017.

We use “races” to demonstrate our competence as glider pilots.  However, it used to be nearly impossible to structure a race on any given day that was truly fair to every participant, thus “bragging rights” by the winner was often marginalized.  Few, if any, of the aircraft were (or are) identical.  Although the ships may appear to be identical, wing loading and variations in polar curves (glide ratios) for various reasons are always present.  All of that said, most all participating pilots will testify that having a glider race is a fun thing to do.  We acknowledge the inequities, have a fun race and we typically follow it up with an enjoyable dinner party – telling tall stories of how we were able to overcome the various adversities that we may have found on course, but then were able to overcome fear and superstition and make it home in time for the BBQ.

When we first initiated the VSA Race Series, back in 2004, we often created a variety of tasks in an amateurish attempt to make them somewhat fair, to minimize the “luck factor”.   The tow plane resources at WSC were more limited than they are today and usually the commercial rides and training rides took priority during the optimum launch period.  Pilots were just then becoming familiar with the concept of Turn Area Tasks (TAT) and the on board computers at the time provided relatively little decision making information to the pilots.  Tasks changed from a fixed distance to a fixed/minimum duration.    In the latter years we usually had enough tow resources to get all competing gliders launched within a single hour and we began using advanced scoring software, along with all of that, a dedicated scorekeeper was often available.  These improvements then allowed us to conduct the races that were more competitive, more fair, and more fun than in the early days.

Photo of the ten foot banner created (by J. Darke) in 2004 for the opening day of the first VSA Race

banner

Why Race?

Note: As with nearly every VSA web page, this page, including the following, has been created by the webmaster, P Kelly.  If you have an opinion and want to publish it here on the VSA pages, please write to me. PK.

The pinnacle of success for a glider pilot is to achieve the furthest distance possible, given the existing atmospheric conditions on that particular day. To fly the most distance, given a limited number of daylight hours, you must fly as fast as possible. Unless you compare your own flying to that of another pilot, you just don’t know how successful you have been on any given day. Rather than simply measuring distance, a more structured method of measuring the comparative pilot skills is to measure speed, but how is that done?

Overview

To race gliders, all pilots must be allowed to start at the same time of day, since strength of the lift varies as the day progresses, with the best lift occurring during the peak of the day.  Additionally, each pilot must be required to fly the same amount of time.  To be a fair race, certain adjustments to the speed flown must be made in order to take into consideration the performance characteristics of each aircraft.  The combination of considerations is called the handicap system and is, arguably, virtually impossible to achieve, but we try.  The speed flown by each glider is adjusted according to the assigned handicap.

How is it organized?

A person entitled the Contest Director (CD) sets the Task to be flown. The CD must designate a task in which all contestants will fly the same amount of time.  The variable distance of the task will accommodate both the highest and the lowest performance gliders.  The pilot with the highest handicap adjusted speed is declared the winner and is awarded the maximum number of points – a score of 1000 points – and the others receive prorated points based on a ratio to the winning speed. For example, if the winner had an adjusted average speed of 50 mph ( receiving 1000 points) and the second fastest averaged 40 mph, then the second place pilot would be awarded 800 points for the day (40 is 80 percent of 50, thus 800 points).

The CD specifies an assigned area for the race, based upon the forecast soaring conditions and the performance capabilities of the gliders in the race.  Every pilot will have the opportunity to begin at the same time of day, and will have their speed calculated based on the distance they travel and the time they are on the task, but a minimum acceptable time on the task will be specified.

The CD:

  • evaluates the estimated soaring condition
  • calculates the minimum duration of the assigned task:
    • selects/ determines an estimated landing time
    • estimates the time at which the last glider will release from tow
    • the difference between the last release time and landing time is then the minimum duration
  • calculates the minimum and maximum distance required for the assigned task
    • estimates the lowest expected handicap speed
    • estimates the highest expected handicap speed
    • uses those speeds to determines the minimum and maximum distance of the assigned task
  • constructs an assigned task to accommodate the above calculations. Minimum time and the minimum and maximum distances are easily calculated.

For example:

  • Minimum Duration:
    • Soaring conditions (and social agenda) will support a landing time of 4:30 PM
    • Considering the number of tow planes and number of contestants and expected launch times, it is estimated that last pilot will release from tow at 1:30 PM
    • Minimum duration will be therefore be specified as 3 hours (1:30 to 4:30 is 3 hrs).
  • Minimum and maximum distance of the assigned task (in this example):
    • Considering pilots skills, glider performance and the expected soaring conditions the lowest expected handicap speed is 45 MPH
    • Considering the same as above, the highest expected handicap speed is 90 MPH
    • Minimum task distance will be 153 Mi (45 x 3)
    • Maximum task distance will be 270 mi (90 x 3)

The CD then selects a series of turnpoints surrounded by circles of various diameters so as to provide an assigned task with a minimum distance of 153 miles and a maximum distance of 270 miles, and he specifies that the minimum time used for scoring the miles flown will be 3 hours.

The challenges for the CD are to predict the soaring conditions for the day, estimate the time at which the last pilot will release from tow and the estimate a landing time. The CD must assign a Task in which every participating pilot will have the opportunity to complete starting at the same time and accomplished during the same number of hours.  The distance flown by each pilot will vary according to the handicap assigned to that ship.

Further discussion

For decades, CD’s have directed pilots to fly fixed distances and then foolishly considered the winner to be the one that flew the shortest time.  How silly was that?

The lift is strongest at a certain time of the day.  Higher performance gliders are able to complete a fixed distance task more quickly and thus will achieve a higher score simply because they flew during the best time of the day.  Slower gliders will take longer to complete the same task, and thus will not have the benefit of flying during the better part of the day.  It is obvious that all competing gliders must remain in the air the same minimum period of time.

Gliders may appear to be identical, but may weigh differently due to pilot weight, configuration, and additional ballast weight. Thus they will have different performance/ polar curves. If a certain model of a glider is identical in construction to another, but one weighs more than the other, than the one that is heavier will be able to fly at a faster speed while achieving the same glide ratio, thus will fly further than the lighter glider.  Some gliders are obviously lacking in the more advanced characteristics such as high performance wings, sleek fuselage design, latest use of flaps, and wingtip modifications, etc..  We attempt to incorporate all of these deficiencies and differences into our handicap system.  Thus adjustments to the score for all weight and performance would be made, if we had a handicap system that was truly accurate.

The purpose of racing is to recognize those pilots who have assimilated the highest level of flying skills, not to prove which type of glider has the best performance.  If you have enough money and desire to spend it, you equip yourself with the most up to date glider and instruments.  But if pilots are going to compete, then the playing field must be leveled to allow every pilot with an equal opportunity to win, regardless of how much they may have available to spend.  To insure fairness, three different mechanisms are used.  Unfortunately a system has not yet been devised that entirely levels the playing field so that each pilot has an equal and fair chance of completing a designated course in the designated time with the greatest speed. We do use a few crude adjustment mechanisms which adjust the score based upon a few limited number of  factors.

1. The handicap system
Since not all gliders are identical, a handicap system is usually used to compensate for manufacturing differences. An older glider with lower performance characteristics will have his/her speed adjusted upward from an established standard, while newer, higher performance gliders will have their speeds adjusted downwards from that same standard.  Some gliders have a polar curve that provides the pilot with a high L/D, but only at relatively low speeds (60 to 65 Knots), while other gliders may have only a similar L/D, but the are able to sustain that same glide ratio while traveling at  30 or 40 % higher speeds.

For example: two gliders, each with a 40 to 1 glide ratio, but one achieves 40:1 at a speed of  65 knots while the other at is able to fly at 88 knots and still achieve 40:1.  : 135% of 65 = 88 knots),

The faster glider would complete the entire race during the best part of the day, while the slower glider, with the same glide ratio would take 35 % longer to complete the same distance.  Since handicap does not take into account the time required to complete a task, Contest Directors must control the time flown that each glider. Alternatively,  CDs may require gliders to compete only against gliders of the same Class, and thus with similar handicaps.

Unfortunately, handicap does not usually take into account the weight or more correctly stated, the wing loading, of the glider.  if you have two identical gliders in a race, and one pilot is 80 pounds heavier than the other, and if the heavier pilot adds 80 pounds of water ballast, then there now is a 160 pound difference between the two gliders.  Each with the same wing, and the same assigned handicap.  The the heavier glider will have the same  handicap as the lighter ship, but will fly at a speed that is approximately 15 percent faster, and yet have the same L/D.  How can that be a fair race?  That issue may be resolved someday.

2. Use of Classes of gliders
Using a handicap to adjust the speed flown is never adequate enough to allow each pilot a fair chance at winning the race. On some days it may be impossible for a 30/1 glider to reach the next thermal, whereas a 40/1 ship can, and on other days, it may even take a ship with nearly 50/1 glide ratio to glide from one area of lift to another, thus we divide the competitions into classes. Gliders that are built with similar performance characteristics are assigned to a given Class. The use of Classes combined with the use of Handicaps would be closer to providing a satisfactory race that was fairly competitive.   A common problem at local levels is that we often have such a variety of gliders that we are unable to establish a single Class.  A third method of contributing to the fairness equation has been used since 2003 and that is, flying a fixed time, rather than a fixed distance.

3. Variations in the Type of Task to be flown.

Based on his assessment of the soaring conditions on that day, the Contest Director (CD) will specify the minimum time that will be used to score the distance flown by each contestant within a give area. Rather than specifying a one mile radius around each turn point, as was done in the past, the CD will now specify a large circle around each point.  Pilots are allowed to turn anywhere within the set radius of each turn point and will be credited with whatever distance they choose to fly between each designated turn point. If a pilot is operating a very high performance glider, he will go deep into each turn point area, traveling a significant number of miles more than the lower performance gliders, but will usually complete the course just above the minimum required time that has been set by the CD. Whereas, a pilot with a low performance glider will choose to fly near the minimum distance required to complete the course, but he too will be sure to finish just above the minimum required time. The end result will be that all pilots will be allowed to compete during that portion of the day when the soaring conditions are most favorable, and yet fly a minimum time as dictated by the CD.

Background info on the evolution of attempts to structure glider races:

Sailplane Racing (SRA) published this in 2003 – https://www.ssa.org/files/member/SRAGuide.PDF

Doug Jacobs, a renowned racing champion has created numerous presentations about racing. Visit the following site and read the one entitled Contest Tasking and Rules.ppt – which addresses: Rules, Tasks and Task Strategy – he sums it all up very well.  See – http://www.dragonnorth.com/djpresentations/index.html

See some world champion info on SSA web site at – https://www.ssa.org/files/member/BR%20US%20Teams%20V3%2004.pdf

Historical perspective on Glider Competitions – see how far we have come – http://soaringcafe.com/2012/08/why-uvalde-why-indeed/

 

 

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Page last revised: 12/22/2016
Questions/ Concerns/ Suggestions should be addressed to webmaster Peter Kelly
Email is gliding@sonic.net

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