A few PGs flew Bills Hill on Saturday. Wind was straight in on launch, but there was a SE cross wind in the air which made it difficult to get up so we've been discussing how to deal with it. I've also been having issues staying in lift and found some tips I wanted to share. Please add your own if you have any.
One strategy for getting up in a cross wind (as I understand it) is to turn upwind. This allows you to better use pockets of ridge lift and should mean you're encountering more thermal bubbles because you're not drifting with the wind in the same lift, you're going against it where you're more likely to find more bubbles. Doing this you can bobble along the ridge making small half turns in broken lift. This gets you just a little higher each time and allows you to get above the ridge and in a much better position to circle when a stronger core comes along.
Gathering all the information you can before launching is critical. You should be watching birds, other pilots, and really focusing on your strategy for getting up and be determined to make it happen (safely). I launched in an increasing cycle and after turning right into the wind I found a few bubbles and did some figure 8s until I was high enough to be able to 360. If you're below the ridge then your best bet may be to fly away from the ridge and hope to connect in the valley at the tree line where the thermal is releasing. I did this on Friday at the Pulpit.
I analyzed my track and found that I often am falling out of the backside of thermals. Burkhard Marten's Thermal Flying book has a chapter on centering in lift and he recommends staying in the upwind side of thermals, not only because it's the stronger part of the core, but because if you fall out of the front you just have to fly downwind to connect again which is much faster and less altitude loss than flying upwind in sink on the backside (leeside) of the thermal.
I normally try to keep my circles pretty constant assuming I'm just drifting with the thermal, but the book mentions that wind will act more strongly on you than it will the thermal which means you will drift out of the back of it - which is exactly what's been happening to me. He also has a technique for determining when to tighten your turn when trying to find the strongest lift. Basically flying straight until the lift starts to decrease and then turning tight to get back into it quickly.
He also mentions that some thermal cores are just too small to make full turns in, especially down low. You have to bank your wing and turn tight in small cores and even then you may not be able to stay in it. But if you're falling out the upwind side you have a better chance of quickly getting back in and having a net gain.
I also read some XC tips in the January USHPA mag. Really good stuff. Go back and read it if you missed it. It specifically recommends reading Burkhard Marten's Thermal Flying. The article then recommends reading it again another 2 times.
Thermalling Strategies
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