Monday, May 30, 2011

Thermal and ridge lift today at Crystalaire

Our club planned an outing for the long weekend, but it did not go as planned due to the weather. The NWS issued wind warnings for the Antelope Valley, and many of our club members decided not to go. I've seen that sometimes the Crystalaire area is not as windy as the surrounding area, and we already had reservations at a place nearby, and we had nothing else planned for the weekend, so my wife and I went anyway. Well, I should have listened to the NWS this time! Saturday started out not too bad, just light winds at ground level, but upstairs it was a different story. Some very experienced glider pilots and tow pilots came back saying it was the worst turbulence they'd ever seen, and by about noon everyone was calling it a day. Sunday was forecast to be cool, cloudy, and windy, so we packed up and went home. These things happen sometimes with weather-related sports.

Monday was looking much better, so I headed back out. It was warm, clear, light wind forecast. The morning inversion was forecast to dissipate, with thermals possible up to 8500' or so. (I use NOAA's soundings web site at Check it out! If a formal sounding is not available for your favorite soaring site, it will interpolate one from the closest available ones.) Forecast high was for 76F, but NWS often underestimates desert high temps, and I know it got up to about 81F in the afternoon.

Some other folks wanted to do dual flights in the Grob, so I flew the PW5, taking off a little before 2:00. I let off in lift at 7700' MSL, and found a weak thermal right away, but it only took me to 8200. Eventually I found some that got me up to 9200, and I went farther east than I have before, just a couple of miles. I'm still kind of conservative at this site - I like to stay fairly close to home until I get comfortable with how much altitude I need to get back from various locations. (I did not take my flight computer today.) I could see other gliders at least a couple thousand feet higher, but I could not seem to beat 9200'.

One problem is that the variometer on this glider is intermittently unreliable. That may sound redundant, but it's true. Some days it works fine, other days it's all over the place. Last time I flew, it was fine, and we concluded that maybe there was water or debris in the static lines that had resolved itself. Well, the gremlins were back today! I intentionally took along my clip-on electronic vario, but there are two problems with it: 1) it's not very loud, and 2) it only tells me about lift, not sink. Flying in the mountains, I'd like to keep an eye on the sink as well. So... although it may sound like an excuse (especially to the seat-of-the-pants gurus), partial vario info makes me not want to go very far into the mountains. I think we need to tear the whole static system apart and clean it out.

Some of the lift was too widespread to be thermal, so I began to think it was ridge lift. There was a bit of a northwest wind - I could tell from my drift. I did not think it was strong enough to really generate much ridge lift, but apparently it was. I need to rethink my image of ridge lift: instead of a classic ridge perpendicular to the wind, this terrain was a bunch of short ridges, some of which were oriented against the wind. So each little spur was generating its own lift in a small area. Something to remember and try to exploit in the future.

I developed a bit of a headache after an hour or so. I turned on the oxygen for a while although I was only at about 8500', thinking it might help... it didn't. So I didn't push it, I came back to some of the closer ridges and worked some well-known thermal generators such as the Chimney. I was able to work a thermal up to 9700'. After about an hour and a half I decided to go out over the desert and try a few things.

I realized some time ago that my flying style is pretty "tame": wings-level most of the time, fairly gentle turns, never getting much above best L/D speed except to get out of sink. I've wanted to loosen up and have a little more fun in the air, but often I do not have enough excess altitude to experiment very much. Today I did, so I played around with some dives and climbs and steep climbing turns. Not quite what you would call wingovers, but definitely more extreme than I usually do. (Yes, instructors, I did clearing turns first.)

I found a few thermals over the desert, and could have stayed up longer, but I came in at just under two hours.

The lift was definitely working today - other club members went to the top of Mt. Baldy - I just didn't quite connect with the best stuff. That's on my to-do list for a day when the instruments are working better, and after I've studied the charts a bit more so I know the distances and escape routes.

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