Strong Windy Day Thermals
Thermals are certainly strange creatures. One day they can be big, round, and smooth, the next they’ll be tight with multiple cores, the next day, there will be sink in the area that was constantly lifting the day before! This can bring frustration, but also lots of satisfaction when we start to build up our experience and start to be able to harness mother natures energy to our advantage. Undoubtedly, you’ll fly on windy days too, so you’ll need to build up your knowledge and skills for these types of days too...
Wind Effect on Thermals
Thermals are updrafts, naturally. They typically drift downwind, but because of their huge amount of energy and mass behind them, quite a bit slower than the wind. Where is the core on a calm day? As you’d imagine, in the center. What about on a strong wind day? You’ll find it on the upwind side, close to the strongest sink too. Already this spells the use of caution, especially at the lower altitudes. Widening out your turn or delaying your turn back in, will see you lose all that beautiful energy you’ve just gained. Consequently of this is that you may lose in your mind where to search for, or find the thermal again, or it'll see you staying in the heavy sink and having to continue on.
The Danger of Thermalling Low
While I touch on strong wind days, when you’re at the point of having to outland, if you get that surge of lift on base leg, never take that one extra turn, just commit to the field and live to fly another day – after all, this is just a game we play and your friends will happily come pick you up!
Centering Thermals When Windy
So how do we center a thermal in windy conditions? Well, don’t be dismayed if you lose concentration, or a few thermals while you learn, even experienced pilots can struggle with this. The first trick is to stay relaxed on the controls as best you can while staying focused. To avoid losing a thermal in these conditions, we of course need to adjust our angle of bank, to result in an oval or egg-like shape. Typically you’ll be at your regular angle of bank at the upwind point, through to the downwind point, then widening it out just prior to flying into the wind (to being quite shallow), perhaps around half of the bank than usual. When you feel the surge or core again, be sure not to delay (for the vario needle to respond), tighten back up, use those sensitive nerves you’ve developed in your backside and trust your instincts. Remember what we said earlier about the strong sink on the upwind side, we want to avoid this! Every thermal is different of course, some require this method every turn, others require this method every other turn, and others, well, of course, it always depends!
Banner photo by John Absolon, 'Got that shot' Images
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.