Exiting Thermals
One important aspect to either soaring in the local area or gliding across country, whether it be for leisure or for speed, its important to put all that energy you’ve just gained to good use, after all, we’ve certainly worked hard for it, why not keep some of it! The local soaring pilot looks to retain their height gained to stay up longer, the racing pilots wants to get around the set task as quick as possible. Exiting a thermal without thought or being lazy, can be just as wasteful as entering and centering the same thermal slowly, so it’s important to stay disciplined in this regard too.
To Stay or Leave
How can we best do this? As with everything gliding, it all depends. Where there is lift, there will be sink. It is a fact of soaring that you will have to cross this area sooner or later. As I’m climbing up in a thermal, I’m constantly looking for reasons to stay and reasons to leave. If the sky ahead is looking questionable, then I think one more circle is warranted when you’re thinking of leaving, that 30 more seconds to reassess can really make a difference to your flight. When the sky ahead is looking homogeneous, you can leave more aggressively, as there is highly likely a good chance that you’ll at least find something that matches your current climb strength. I’m looking at the wind and I’m building my picture of how the air is moving for the day with respect to leaving the climb.
High wind days or clouds ahead? Thermals in this case can have an elongation-like shape to them, or rising air still feeding into them from upwind. The wind aligns the hot air, which forms the cloud streeting ahead. In these cases, after I’ve decided to leave the climb, I’ll often roll out gently and into the wind, feeling the energy beneath my wings and directing my glider towards the next goal cloud. It’s hard to describe when to speed up, but in the following paragraph, you’ll see why.
Through the Core
The other method is to anticipate your rollout heading from 90* prior, at which point we can tighten the turn to fly straight through the core on the way out. This increases the speed in the lift, yes, but more importantly, it allows you to spend less time in the sink – remember the point above, where there’s lift, there will be sink?! By spending less time in the sink, we are able to do two things, accelerate away from our mates, and spend our height just gained more wisely – after all, we likely fought very hard for those feet.
Clear Traffic when Exiting
You’re probably already thinking too, the latter method needs some care, what if there is a friend or competitor below you? In this case, you have no other option but to respect them and their space, roll out gently, be predictable, come home safely to fly another day – the 50’ you’ll gain from the most efficient thermal exit, just isn’t worth meeting someone on the thermal exit…
Safe circles as always :)
Banner photo by Maciej Gębacz - Heimdall Fotografia
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.
