One good reason is fiberglass construction, modern airfoils, and heavy
gliders. Fly slowly at 1-26 or K-6 speeds, and even a pellet vario can
work well. Blast through the thermal at 90-100 knots, full of water ...
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to


So, the question becomes, what software is best for what conditions? This post assumes that the varios input to the software shows true lift without gusts etc.

The PC SeeYou stats showed that on 200 km of distance yesterday, with overdeveloped cloudbases as low as 2500 ft AGL, average climbs were as low as 1 knot or zero, getting blown home on wind. Most "circles" showed lift and 4 knot gusts at opposite sides of the circle, and sink everywhere else. Moving to one direction to the other resulted in the same thing with a different set of short term lift bubbles. That's trying both slow 45 degree banks, or back and forth sniffing in the bubbly area that had more lift than sink. When you're that low you have to do what you have to do.

Other people's flights on the OLC that day showed pretty mush the same conditions/results, but I didn't see anyone doing the "sniff around" method.

Sometimes you just have to fly around a bubbly area that has more lift than sink, and a 1 minute average lift option on a very weak bubble day would help. That's about the size of a "sniff around" area, which isn't a thermal at all even if there is more lift than sink. "Last thermal" stats on software I've used/seen so far stops working as soon as you go straight for any length of time.

So, what I'm saying is that the software development and discussion seems to be optimized for classic Texas lift silos on nice days, not for overdeveloped low weak days when you'r relying on the circulation from latent heat of liquidization just under cloudbase.

The suggested XCSOAR thermal assistant screen http://bugs.xcsoar.org/raw-attachmen...lassistant.png would work well for these conditions if it would show a one mile sniffing area with bubble clusters, even if you're flying back and forth rather than circling. The outer ring would still work for the classic thermal situation.

So, I would suggest that Tobias' proposal works for more situations than Andrzej's objection, since not all of us can assume classic thermal silos of lift on non-classic lift days.