After we release over the ridge, the next crucial step is to test out the soaring conditions. We are primarily interested that the thermals are working and that the wind strength and direction should make the ridge work nicely.
We often try to find a thermal right off of tow. This works well as it gives more time to assess the conditions and gives us confidence that we can find a thermal later when we want to get back home. If we find that the conditions don’t look all that solid below us, we will often take this thermal up to cloudbase and fly the rest of the day in the thermal band! As we thermal, we note the wind strength and wind drift as the thermal takes us a couple turns downwind of where we started.
Next, we compare our drift to wind markers at ridge top. At Blairstown, the Upper Reservoir is an excellent wind indicator. You could also look at the steam plume rising off of powerplants, flags, and trees dancing at ridge top.
With some experience, you will be able to look at these wind markers and use them to accurately estimate wind strength.
You could also pay attention to your crab angle on the straightaways; the more you must crab, the stronger the wind.
Ideally, you want to see the wind strength above ridge top be somewhat greater than at the surface. If you don’t have that wind gradient, then the top of the ridge band might get cut off lower than you would expect.
Normally, you want to see winds 15-25 knots at ridge top, within 30 degrees of perpendicular for the section you intend to fly.
Once you are satisfied that the thermals are working well and that the wind looks reasonably solid at ridge top, you test out the “high” band. This entails settling down to 2,400ft, checking your variometer and feeling if there are gusts coming up underneath the glider. A 1-26 will sink at ~200fpm at best glide speed. If you are in “good air”, you will be settling down only at 100fpm. Even though you might not be sustaining, this suggests that the ridge is working underneath you.
As you are settling down, you should be positioned to leave at one of the two exit points (Doc’s Thumb or Upper Reservoir). Once reach a decision point at 2,400ft MSL. If you feel confident that the ridge is working underneath you. Otherwise, you will strongly consider leaving back to Blairstown Airport. If you elect to settle down lower, you will becommitted to the field at the base of the ridge should the ridge not work.
As you settle down lower yet, you will probably feel the lift strengthing and you have to speed up to maintain the same height above the ridge. Speed up to 65-70 mph in a 1-26 and settle down as low as the ridge lift will let you go. If you get down to 100 ft or so above ridge top, you are now “down on the trees”. Sometimes, the ridge lift is so strong that you can’t get down on the trees and will still be several hundred feet above the mountain!
At this point, you have successfully tested the ridge! Now you could go and stay low and fast, or you could transition back into the higher “float” band if you prefer to avoid the beating.
The whole process can take you an hour or more to build your confidence in the conditions. Experienced pilots can judge the conditions considerably quicker and go through the process much more rapidly if they want to. However, they are still doing all of these steps; we don’t simply drive down on the ridge on a hope and a prayer.