My friend Jim has been wanting to go for a glider flight for a long time, and we finally decided the only way we'd work it into our schedules was to take a day off work and just go. He'd been in a small power plane before, so we figured he'd do fine in a glider. Today the forecast for Crystalaire was for 99F, good thermal lift, winds out of the west-southwest at 10 to 15 knots.
We took off about 1:00 in light south-southwest winds and let off in good lift over the Second Ridge. We very easily gained 2,000 feet, and then another 1,000. Couldn't quite break the 10,000' mark, but it was working well. I kept the banking to about 35 degrees, and Jim handled it just fine. I looked around for more lift, and all I found was light sink and some turbulence upwind of the ridge. It was a little puzzling, because the south side of the ridge wasn't working like ridge lift based on where I thought the wind was coming from. Not finding a second thermal, we dropped off the hills and out to the desert... and found no lift there either. We landed after 38 minutes. I knew the lift must be better than that, because other gliders had been up for an hour or more. Jim was game, so we decided to give it another try.
We let off again in good lift, a little higher this time. I heard two other gliders on the radio trying to make visual contact, and one said he was at "13,400 in wave over the Punchbowl". Hmm... I'm over the Punchbowl too, but about 4 to 5 thousand feet lower. Huh? Wave? Duh! Of course! Wave! That wasn't thermal lift last time, and it wasn't random turbulence south of the ridge, it was rotor! The wind was blowing over the tops of the mountains, bouncing off the floor of the valley south of Second Ridge, and going up. So... I flew parallel to the ridge and immediately contacted smooth wave lift at about 5 knots. Then 6 knots. Occasionally 8 knots. Eventually 10 knots! In no time we were over 11,000 feet. I found where the rotor started south of the wave, and found the apparent east and west limits of the lift. We got as high as 12,200 feet, though much of the time we were down around 10,500. This is more like it!
This was really only my second time flying in serious wave lift, so I spent some time exploring the limits of it and just enjoying the view and giving my friend a nice smooth scenic ride - that wave lift is amazingly smooth! After about an hour and a half we decided to head back out over the desert and shoot for a two-hour total total time. I knew that losing 6,000 feet would take a while. Heading north, I found sequential patches of moderate turbulence and smooth lift. So I think I traversed secondary and tertiary waves. As we were wrapping up our flight, I heard one of those two other gliders going in for a landing, but the other checked in at 16,000'. We ended up just two minutes short of two hours on that second flight.
So my lesson for today: a south or southwest wind across the San Gabriel mountains can set up wave where I have been looking for thermal and ridge lift. What's surprising to me is how short the wavelength is. From the top of the ridge where I think the wind is getting deflected upward, to the upward flow of the primary wave seemed to be about just 3.5 miles. All the soaring educational materials I've seen about wave talk about the wind bouncing off a stable air layer down low, not off the ground, so I have not been thinking about the wave setting up right in the mountains, but that's what it seems to be doing. And the wind was not all that strong: 10 knots on the ground, not sure how strong at altitude. So I need to think about wave forming in a wider variety of conditions than the books talk about.
A great day!
Monday, June 27, 2011
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 http://www-frd.fsl.noaa.gov/mab/soundings. 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.
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 http://www-frd.fsl.noaa.gov/mab/soundings. 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.
Sunday, May 08, 2011
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Monday, April 18, 2011
Thermal Season Begins with Passenger Flights
My cousin R and his wife J have been wanting to go soaring for a while now, and I've been waiting for the thermal season to begin so I could give them more than a "sled ride". Well, it's been warming up in the high desert, and reports out of Crystalaire have indicated that the thermals were popping the previous weekend, so things were looking up. We headed out there on Saturday. (The forecast high temperature was 87F.) As it turned out, no one else in the club was planning to fly the Grob that day, so I was able to take my time and show them all aspects of the ship as we washed and inspected and prepped it. Both had been in small planes before, so they were interested and eager.
We found a couple of other gliders that were climbing, so we slipped in underneath them. I had explained earlier that this was one of the fun aspects of soaring: flying in a "gaggle" with other gliders. We worked it for a while and were able to gain a thousand feet. I kept checking to see if J was OK with the circling, and she was doing just fine. This thermal seemed to top out at 6,000' MSL, so we went looking for others. Didn't find any... came back to this first one... and it was no longer working. I never did find more lift in the region, so we came back in, for a total flight time of 42 minutes. That's probably about right for a first glider flight anyway. This time my landing was smooth, that is until turning off the runway into the stopping area. Wow, that dirt area is rough!
R was up next, and we took off just about one hour after the first launch. Things had heated up, and we felt a bit more turbulence on tow, but not bad. R video'd the takeoff and tow. This time I held on a little longer, and we towed further up the Second Ridge until we found some good lift. This tow was about 3,500' AGL. We immediately climbed about 500' in 2-3 knot lift. Not bad, but nothing spectacular. It seemed kind of disorganized, and I couldn't find more than 1 knot over the hills after topping out that first thermal. Not much over First Ridge or the punchbowl either, so once again we headed for the "house thermal" west of the airport. There we met up again with two other gliders, so R also go
t to fly in a gaggle, and was a great help keeping the others in sight. R also was not bothered by the circling. (I've written before about how passenger flights are sometimes a difficult balance between circling to stay aloft, and trying to have a gentle flight to avoid causing airsickness.)
The Grob had had some maintenance done on it earlier in the week, so I took it up for a checkout flight to pattern altitude before flying with passengers. Although it was well before noon, there were little bumps on tow, so it looked like things would heat up. I tried for a precision landing right on the numbers, and bounced the landing - haven't done THAT in a long time.
We had lunch and waited for a few others to stay up so we'd be pretty sure the thermals were working. J and I took off about 1:10, took a 3,000' tow and let off over the Second Ridge (there were some decent bumps on tow). We didn't find much there over the hills, and I'm new enough to this area that I didn't want to get too low, so pretty soon we headed out over the desert.
We found a couple of other gliders that were climbing, so we slipped in underneath them. I had explained earlier that this was one of the fun aspects of soaring: flying in a "gaggle" with other gliders. We worked it for a while and were able to gain a thousand feet. I kept checking to see if J was OK with the circling, and she was doing just fine. This thermal seemed to top out at 6,000' MSL, so we went looking for others. Didn't find any... came back to this first one... and it was no longer working. I never did find more lift in the region, so we came back in, for a total flight time of 42 minutes. That's probably about right for a first glider flight anyway. This time my landing was smooth, that is until turning off the runway into the stopping area. Wow, that dirt area is rough!R was up next, and we took off just about one hour after the first launch. Things had heated up, and we felt a bit more turbulence on tow, but not bad. R video'd the takeoff and tow. This time I held on a little longer, and we towed further up the Second Ridge until we found some good lift. This tow was about 3,500' AGL. We immediately climbed about 500' in 2-3 knot lift. Not bad, but nothing spectacular. It seemed kind of disorganized, and I couldn't find more than 1 knot over the hills after topping out that first thermal. Not much over First Ridge or the punchbowl either, so once again we headed for the "house thermal" west of the airport. There we met up again with two other gliders, so R also got to fly in a gaggle, and was a great help keeping the others in sight. R also was not bothered by the circling. (I've written before about how passenger flights are sometimes a difficult balance between circling to stay aloft, and trying to have a gentle flight to avoid causing airsickness.)We were working the thermal pretty well, when suddenly my portable radio "jumped" and landed down by my foot. Since I was flying from the rear seat to give my passengers the better view, I could not use the glider's built-in radio (there's only a boom mic in the front seat), so I was using my handheld, my headset, and my Velcro-attached push-to-talk switch. I have a wide Velcro strap that goes around my leg, and the radio's belt clip goes on the strap. Well, the belt clip on the newer, larger battery pack is a little smaller and does not clip firmly on the strap. It's never caused a problem until today, when it crept off the strap and fell down in the footwell. As soon as this happened I straightened out and left the thermal to deal with the radio. It was j-u-s-t out of reach - you can't lean forward in a four-point harness. Fortunately gliders can fly pretty well by themselves for short periods of time, so I trimmed it for minimum sink speed, leveled the wings, centered the rudder and went hands-off and feet-off. Also fortunately, there was no traffic in the direction we were gliding, but I still had to keep a lookout. I was beginning to think I was going to have to unstrap, when I finally got it by the antenna. By the time I got it back in place and plugged in, and dealt with another couple of distractions, we had lost a few hundred feet out of this already fairly weak thermal.
We cruised all around the airport area, even tried to poach off another glider, but he wasn't climbing either. We didn't find any more lift, so we came in for a smooth landing at - how about that? - 42 minutes, same as the previous flight.
Once on the ground, I checked with a few other pilots and several said the same thing: we found one good thermal to keep us up for a while, then nothing.
So, all in all it was a fun day. Both of my cousins enjoyed their intro flights, and we were able to thermal long enough for them to get some idea of why we crazy sailplane pilots keep coming back for more.
Sunday, April 17, 2011
Flight trace video of my wave flight
I sometimes record traces of my flights with the SeeYou Mobile program running on an iPaq. I then play them back on the SeeYou PC program to study how things went. I've recorded a playback of my April 2 wave flight and posted it on YouTube - first time I've figured out how to do that. It's played back at 10 times the actual speed, so my 2 hour and 20 minute flight plays back in 14 minutes. Here's the link.
If you just want to see the time when I really connected with the lift and started climbing at a good rate, go to 8:05 through 11:42 in the movie (which is about 13:42 to 14:18 on the flight clock).
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