Not Committing Yourself to Every Thermal
Take the strongest thermal. The question is how do you know that it is a strong one or not? I am sure you all have felt a really good one when you just know right away it is going to be a great one (just take those ones). With experience, you can guess pretty quickly on the pull-up if the average is going to be what you have been averaging, stronger, or weaker. I could tell you that I can tell the difference between 3.2 and 3.6knt average right on the pull-up, but I would be lying. I would also be lying if I said I don't guess wrong.
Don't be too aggressive in your pull-up unless you are positive this will be the one. Not being too aggressive at the start of the turn allows you to abandon the turn easier or switch directions easier. Many times when flying with George in the Nimbus 4DM we would level off at 70knots.
Only slowing to 70knots has some advantages. It prevented us from being really slow as we fall out of the other side of the lift. There is no worse feeling than being at minimum sink speed when you encounter sink. It takes a lot of altitude to do the initial acceleration. It also keeps you more committed to going straight and not stopping to take every thermal.
I have had many times when I have to ask myself why am I thermalling here? It is really frustrating when you realize that once you have made a 180-degree turn. You only want to take the good ones and the thermal has to convince you it is good. You want to be more in the mindset of cruising and only stopping in the good ones. Unless you are in a 1-26, then you are stopping at most of them.
With all of this waiting and not making an immediate decision you cannot wait too long either. Once you hit the sink then decide to turn it might be more challenging to get back into it. You will also be turning in the fastest descending air circling around in it to get back to the lift...it will not be good. Most likely the best idea to skip that one.
As you are cruising along you start to feel something, the vario begins to register, you start to pull and as you pull you begin to decide is this thermal selling me on stopping? If you are still undecided then you might only slow down a little and possibly start to wonder in the direction you think it might be.
If the thermal did not sell you on stopping then you level off and start to let the nose down before you run into the sink. Typical days in Australia we would cruise in the 90+knots range and slow down to 70knots.
If the thermal sold you on a good push and a strong vario reading then you would continue to pull the nose up and start the roll while still carrying energy. Starting the turn once the speed is bleed off.
Garret Willat holds a flight instructor rating with over 8000 hours in sailplanes. His parents have owned Sky Sailing Inc. since 1979. He started instructing the day after his 18th birthday. Since then, Garret has represented the US Junior team in 2003 and 2005. He graduated from Embry-Riddle with a bachelor's degree in Professional Aeronautics. Garret represented the US Open Class team in 2008 and 2010 and the Club Class team in 2014. Garret has won 3 US National Championships.
