Introduction To Thermal Duration (TD) Contests

By Bill Rakozy
President, MRCSS 2003

Thermal Duration (TD) soaring can be relaxing, rewarding and challenging all at the same time. In fact, many RC soaring pilots just stop at this juncture, which is a great place to be. Over time however, many a fun-fly pilot have honed their flying skills to the point where it’s enjoyable to pit their flying skills against one another, just for the fun of it. Like golf, once you learn to hit the ball fairly well, you want to compare your “score” with others! That’s where TD soaring contests comes into play.

Contests are well established in the world of TD soaring and there are many opportunities available across the US. Local soaring clubs like MRCSS sponsor contests on a regular basis. In fact, in 2003 the MRCSS flying calendar supports half a dozen weekend competitive events. Our contests are very low key and fun to be a part of. Actually, I like to think of our soaring contests as “learning events”. In reality, TD soaring is a contest against yourself most the time. You know what must be done, but can you do it?

Most TD contests require two flying skills, which must be executed fairly well if you are going to be competitive. The first is staying aloft, until you are ready to come down. The second is landing with accuracy. Staying aloft requires good launching techniques so that you come off the winch or hi-start as high off the ground as possible, with some idea of where you are going to begin searching for thermal activity or “lift”. Otherwise, you will looking for a place to land in 2-3 minutes. A “timer” starts the clock the moment you separate from the tow ring; and stops the clock the moment any part of the aircraft comes in contact with the ground.

Flight Task

In a TD contest, you are given two assignments: (1) a flight task and (2) a landing task. You’ll be awarded one point for each second of flying time. If you fly beyond the assigned task, you lose points. For instance, if you are given a 6-minute flight task, you will be awarded one point for every second in the air, up to 360 seconds (points). 6 minutes x 60 sec/min)= 360 points. If you fly 6 minutes and 15 seconds, your score would be 360 points (-) 15 sec or 345 points total (plus) your landing points if any. Flight tasks require a good flight plan while in the air. It takes practice to know how long it will take to come back to the landing area at the exact moment your assigned flight task is complete.

Landing Task

There are many different ways to award landing points. A very common method is to fix a “landing tape” to the ground with a nail in one end. The free end can scribe a 360-degree circle. If the nose of your aircraft is anywhere in this circle, the tape will read how many points you earned. Obviously, the shorter the tape used, the more difficult the landing task.

If your nose is resting in the 6” center bull’s eye circle, it is worth 100 additional points added to your flight time. (That’s like flying 100 seconds longer than the other guy!) Other landing requirements are: the plane must be upright when it comes to rest and not loose any of its parts (canopy, tail section, etc.) to receive landing points.

Flight Rounds

A contest event usually gives a person the opportunity to launch and fly the “task” between 3-8 times (called “Rounds”) in a day. It all depends upon the size of the group and how fast things are moving. The CD (Contest Director’s) usually determines how long the day will run and when the contest if officially over.

Preparing To Compete

So, if you have been flying for a few months, or a few years, and feel “the call” to participate in a club contest, how can you prepare yourself to do the best you can? This article can’t possibly begin to cover all the individual items, which you must address, but I’ll mention a few which come to mind. Your best bet is to find someone who is more experienced than yourself, and spend a lot of time flying with them. Ask lots of questions. Practice “flying under control” every chance you can.

Getting your plane ready to fly!

Will it hand launch and fly into the wind in a straight line (no wing warp)?
Is the elevator trim set to land slightly nose down, but not too steep?
Is your CG (Center of Gravity) at or slightly behind where the kit plan calls for it?
Have you given it 10-15 test flights to check the trims and you feel confident flying?
Rx (Receiver) battery freshly charged?
TX (Transmitter) battery indicating full strength on the Tx screen?

Here is my pre-flight check list which keeps me out of trouble:

  1. Select Model (On my Tx screen)
  2. Crystal OK? (Tx and Rx on the same frequency?)
  3. Antenna Up
  4. Wipe Tx Up (All switches in their proper position)
  5. Switch On (Both Sailplane and Tx)
  6. Spoilers Down (Launch pre-sets in the correct position)
  7. Up/Down/Left/Right (Is everything moving freely and in the correct direction.)
  8. Tow Hook (Attach tow ring on planes tow-hook)
  9. Pulse Winch Pedal (Be ready to take corrective action in the event of a “pop-off”.

Note: I have this checklist taped to my transmitter and read through it EACH TIME I launch. This pre-flight checklist served me well at the recent LSF/AMA NATS as I was flying two different airplanes, on two different frequencies, using two different “model set-ups” on my computer Tx, all on the same day. No problems to report.

LSF “Fast Track”

I’m convinced that each and every individual who discovered “soaring” and either built or purchased their first sailplane, all walk the same path to success. No one gets a free pass to the head of the line. While some seem to run the path to soaring success, most of us take one small step at a time. It’s called learning. Learning by doing; learning by reading; learning by watching others; learning by asking more experienced pilots and builders how it’s done; and learning by making lots of mistakes. Mistakes are all part of the walk to soaring success. At the recent 2003 LSF/AMA NATS, I heard other who watched Joe Wurts some 20 years ago, do some fairly dumb things while flying his airplane. However, Joe kept pressing forward and today his flying skills are legendary.

In order to fly a timed task and land with accuracy, I believe it will take the rest of your lifetime to perfect those flying skills. That’s what keeps me coming back for more! It is difficult to “out grow” the sport of RC soaring and it’s seldom boring. The more airtime you log, the more comfortable you will begin to feel with your plane under all wind conditions; you will be spending more time flying and less time fixing; and you will arrive at a brand new flying level, regardless of where you begin “your walk”.

It’s my firm belief that regular participation in the League of Silent Flight (LSF) skills development program, is the best (fastest) way to improve your flying skills in the shortest amount of time. And the best part of LSF is you get to progress at your own pace! You determine how fast you want to “walk the road to success”.

To achieve Level 1, you must focus all your flying attention and skills to “ flying under control”. Beginning pilots usually launch and just come down whenever it happens. And they’re usually delighted when they land someplace on the flying field which doesn’t require crossing the highway or drainage ditch! It’s not uncommon for a club member to stay at this level of flying proficiency for years at a time. However, there is another way.

To achieve LSF Level 1, for the first time in your brief flying career, you will be “required” to land in a 3-meter circle and have someone be your witness. In fact, you will be required to land (with a witness), 5 different times before you can begin working on LSF Level II. Level II requires you land 10 times in a 1.5 meter circle. By the time you have completed both Levels I and II, your flying skills will have improved dramatically and your enjoyment of this sport will be at a new and accelerating level of knowledge and interest in this hobby! You will look forward to any and all contests opportunities, instead of trying to convince everyone around you that “contests aren’t for me”.

I hope this brief introduction to TD Contest Soaring will encourage you to fly our weekend contests and become involved in the LSF program. Contact Bill Rakozy, your LSF Club Coordinator at This email address is being protected from spambots. You need JavaScript enabled to view it. and he will get you going for only $2.00. (The best $2 bucks you will ever spend in this hobby!)

Visit the LSF Web Site at:

This website contains all the information you will need to get you fired up! Read it all and then get started working on your LSF Level 1 tasks. Also check out the LSF link on our home page to see who in our club is involved in LSF and more importantly, who is advancing in their flying skills!

But above all, enjoy your walk down the road to soaring success!