Finding Good Thermals

One thing that is said time & time again is that the greatest improvement in our achieved cross-country speed will come from increasing our average rate of climb, but how can we work towards this? Practice makes perfect of course. In all reality, once a thermal has been found and centred, most pilots will climb at around the same rate, and most gliders are reasonably similar in performance. So are others doing to improve their speeds or enjoyment of the skies that you might not be? What are they looking for, and what techniques are they using to help find these stronger thermals? 

Feel & Hear the Airflow

Using the "feel" of your glider is probably the greatest factor in successfully finding good climbs. Being familiar with your own glider is vital, as is a basic understanding of thermal structure. Fortunately, this understanding does not need to be too technical, put in 20% effort on this & you'll get an 80% reward - so it is useful to know what a typical airflow pattern around a thermal is likely to be. More importantly, what does this airflow feel and sound like from inside your cockpit? Let this last sentence sink in for a bit, reread it. 

Transition from Sink to Lift

Dead & heavy, that's the feeling of the sink surrounding a lift area. As you progress closer to the lift you will pass through the turbulent zone where there is some strong shear happening between the sink and the lift. This area will feel bubbly, with a transition from a down indication to what we are looking for, the up part! Shortly after this turbulence, you will feel a strong, smooth surge (quite often you'll sense the glider accelerating, the ASI will show that you are) as you enter the main laminar flow of the thermal core. The cockpit should sound quieter. When you're in the core too, you'll notice that the controls will feel like they are 'biting' the air & working better than usual. The reason for this is that the airflow over them is smooth and organised.

Obviously, these indications will only occur as described if you manage to fly directly into the centre of the thermal!  But often this doesn't happen, so what is really important is to recognise quickly where you are in relation to the good bit, by feeling the characteristics of the air you are in. Turn towards the rising wing, but not always this is so obvious. Hold the stick lightly & keep the vario noise low, it is impossible to hear the airflow around the cockpit when it's too loud, finally, look up and outside. Look, listen and feeeeeel. This is not easy and takes some time and dedication to master, but any effort you put in here will be rewarded.

Moving from Bubbly to Smooth Lift

For example, if the day is providing regular six-knot climbs, and having flown under a promising fresh cumulus, you are rewarded with an erratic four that feels rather bubbly. The well-in-tune pilot will realise that indeed there is a good climb quite close, but that they are currently positioned in the shear layer on the edge of the thermal core. First of all, they will recognise this by carefully paying attention to the feel of the different parcels of air as they circle up, building the picture as to which direction they must move to find the best lift. This may be just a moment of smooth air to centre towards or a section of the turn that is more turbulent, to move away from. This is certainly not easy, it is something that takes a very subtle feel and intense concentration. The good news, we can all learn to do it. Other gliders nearby are good measures, don't be too proud to go over to them if they are going up faster. Use the time to lock in the lesson as to the feelings & sounds you get along the way to - free training. Remember always, we are looking for that smooth, laminar core that gives a big push from below.

Happy climbing!

Banner photo was taken by Sophie Mahieu

 Adam Woolley was born into the gliding world, being the 3rd generation in his family. Going solo at 15, his thirst for efficiency in soaring flight & quest for a world championship title to his name has never wavered. One big passion is sharing his experiences & joy with other glider pilots all around the world. Adam is an airline pilot in Japan on the B767 & spends his off time chasing summer around the globe. He has now won 7 national Championships & represented Australia at 5 WGC's & 1 EGC.