|Mt Diablo beckons the bold pilot...|
Weather Warm-Up ExercisesSometime around last Wednesday Ramy started commenting that Friday was looking favorable, and a couple days of weather discussion ensued. I got into the spirit, so I did my best analysis of the RASP, and asked Ramy what he thought. My analysis went something like this (highly abridged, however, so the reader can get through it without lapsing into a coma):
- Thermal updraft velocity looks best between Mt. Diablo and Byron, better than over the Diablo Range.
- On HCrit, the Diablo range looks better, roughly 1000 feet higher.
- Average wind in the BL is southwesterly, weak over the Diablos, somewhat stronger in the north.
- Cu cloudbase is saying about the same thing as HCrit.
- Max up/down convergence shows a nice line from just south of Byron over to Rel1.
- The Byron Sounding shows normal lift to 4200, and maybe saturated lift on up to 8500.
- The Sierra NAM HCrit and Thermal Velocity shows a demarcation line cutting NE-SW across the bay area, with little potential to the north and more to the south.
Van, I'll spend more time later to answer in detail, but I will start by saying that I hardly use the RASP, never use the thermal updraft, and rarely use the convergence. I don't find them very useful. I use NAM, BLTop, Cu Potential and Cu Base and total cloud cover, which gives me 90% of what I need.
His second response was longer and more detailed, and contained a lot of material from his weather and XC briefings on-line in the Club documents, so I will omit it here.
Friday's FlyingLarry put out a call for a tow pilot, and Rolf volunteered. Way to go, Rolf!
Ramy, Marianne, Larry, Morteza, and I all decided to fly (in TG, P1, FP, MA, and 1YC, respectively). Actually, Morteza showed up to put his plane back together, as it had its annual the previous Saturday, but once he saw all the puffy white stuff in the sky he decided to step up the pace of the reassembly and fly.
To make things even easier on us, Ken Ferguson arrived; he said he wasn't going to fly, as he needed to fly dual with someone and everybody else who showed up to fly was using their privately owned single-place glider. But he decided to hang out (a day at the airport, even not flying, beats a day just about anywhere else!), and since nobody else was doing it, he stayed most of the day, acting as Field Manager. Way to go, Ken!
It was a lot of fun to see five private ships all being put together on the line at once in Byron. I don't think I've ever seen that many all at once.
Ramy's final prediction was that it would be a fine day, with lots of Cu popping up. The overcast line had moved north and it was looking promising, with 4-5K bases over Byron. It looked to him like a great valley day to run south and east towards Yosemite, and east into the valley would likely be better than the Diablo range. For those not flying XC, he suggested the playground would run from Mt. Diablo to Tracy. As you can see from this photo of the Brentwood area, taken from 1YC later in the day, there was certainly Cu a-plenty!
|Brentwood and the Delta, with lots of Cu all over the sky.|
The Pireps (such as they are)As usual, Ramy was the first to launch, with Larry off second. I launched third, then Marianne, then Marianne again on a relight. I landed sometime after Marianne's second launch, and helped launch Morteza. I grabbed some lunch, and then took a second tow myself. Unfortunately, there isn't too much detail in the pireps that were filed.
Here is the sparse account Larry provided:
|Larry's flight. 138 km, 158 points on OLC|
Was a very nice soaring day even though the bases were not as high as you'd like (actually, for me, they're never as high as I'd like. My flying mantra is, "If only the bases were another 1000' higher...... ;-)Ramy launched 1st, then me, then Van, then Marianne, then Marianne again, then Van again and somewhere in there Morteza got his glider all reassembled after his annual and flew. To Stockton, of all places. But I'm sure Morteza can provide a good explanation.
I didn't get far from Byron as I'd expected but I'm sure I would have gone way further "if only the bases were another 1000' higher....... :-)
Thanks so very much to Rolf for volunteering to tow. We owe him big time. Thanks for Ken Ferguson for serving as field manager. And thanks for Ramy for picking the right day to fly.
Marianne's account is even sparser:
|Marianne's flight: 128 km, 135 points on OLC|
Yes, thanks to Rolf and Ken – hopefully you got some vicarious enjoyment out of the day.
I made it within a stone’s throw of REL1 although releasing near BYRON – I got knocked down when I tried flying east to join Morteza & Ramy in Stockton.
Marianne got up over the high ground of the Diablo's while the rest of us stayed mostly over the valley.
Here is her trace:
But Ramy's account is, well, so sparse as to be nonexistant. He didn't file one! But I grabbed his trace, anyway. He did go visit the east part of the valley, northeast of Stockton, but then he couldn't resist the siren call of the Diablo range, getting south to the Gustine area. Here's the skinny:
Flying was indeed delightful today. Ramy, Larry, Marianne, Shannon, and I all flew our gliders. Marianne and I each took two tows.
My highlights are these: two flights, the first 1.3 hours, the second 1.8 hours.
|Van's first flight. 58 km, 70 OLC points|
The first was kind of cool for me, as it was my first true XC flight solo. While it was only to Tracy, for the first time I had to commit to using an airport other than the one where I took off if I was to proceed. I was low enough that I had to either go back to Byron or go on to Tracy, and chose to continue. I was pretty nervous about that, but there seemed to be plenty of clouds, and thus plenty of lift.
Despite a plethora of clouds, the further south I got the more sparse the thermals. By the time I was over the airport the lift around KTCY was hard to find, hard to center, and hard to work. I was pretty sure I was going to have to call Rolf for an aero retrieve. I ended up finding a thermal right over the Tracy Airport that enabled me to climb high enough to strike out northward, and a mile or so later I hit a thermal that took me up enough to get safely back to Byron.
(In honesty, it was probably never in serious doubt, because I have so much safety margin programmed into my XCSoar, but I assumed all the safety would get eaten up by the S-I-N-K that I remain convinced is always out there ready to grab me!)
Now an odd thing happened as I got back to Byron. I kept gaining on my final glide, so that when I hit the region of the airport I was at 2000 feet, plenty of altitude to play around and look for the next thermal. But I had spent the whole trip back from Tracy concentrating so much on just getting back to Byron, that when I got there, I just, well, landed (out of habit, maybe!). I made a really nice landing, and managed the energy well, turning out at the second turnout (without dragging the wingtip through the gravel, you'll be happy to know, Brian!) and rolling to a stop just across the hold short line. But there I was, sitting in my glider, already off the runway, so in no particular hurry to get out, waiting as Ken drove up in the golf cart with my tail dolly, looking at the gorgeous Cu all over the sky, thinking, "Why the hell did I land this thing, instead of staying up to play?"
So I decided to make the best of it, and Ken towed my glider back down to the staging area, where we arrived just in time to launch Morteza. I decided to take a lunch break, and eat my sandwich before taking a second tow. Ken said he was about done for the day, and I told him to go ahead and take off, because with no traffic I could push the glider into position on the runway, get in, and launch without a wing runner (I'd done that several times before, and once before in 1YC. So Ken took off (THANKS, Ken, you were great!), and I called Morteza to ask if I could borrow his wing wheel to get 1YC into position; he said , "Go for it." Man, I have got to get one of those, it makes moving the glider singlehanded a breeze! Rolf reminded me to hold the stick hard over to raise the wing as soon as possible. We started out, and with the dragging wingtip I was being pulled hard to the left, right toward a runway sign. I was holding the stick hard over, hoping I would get aileron authority before I had to pull the release, and I did (just barely -- my release-pull fingers were itching!)
|Van's second flight. 86 km, 98 pts OLC|
My second flight was more relaxed than the first, mainly because I never got remotely close to getting out of glide from Byron. I hit a great thermal right off the tow, climbed to 5300 feet. I called P1 on the radio, to see if Marianne was still flying, and when she answered I asked where she was. She replied, "I think I'm right underneath you," and when I looked down, sure enough, there she was, several hundred feet below and working the same thermal. A few minutes later we separated as she moved a bit further west. She called back to see where I was, I said, "I'm at the top of the thermal we were working, just below the cloudbase at about 5000 feet." Marianne replied, "That's funny, I'm at 4000 feet, and I am right at cloudbase!" Both my altimeter and my XCSoar GPS said I was at 5000; and her instruments put her at 4000, and we're both right below cloudbase. Uneven base altitudes are not unusual, but Friday the clouds had mostly been very consistent, so the uneven heights seemed out of place. Here is a view of Las Vaqueros reservoir; you can see how consistent the cloud bases are.
Once I reached the cloudbase, I took a leisurely flight over toward Mt. Diablo, using the altitude I had and not worrying about thermaling.
Eventually I turned back toward the reservoir, and when I was back near the dam I found a thermal that rook me right back to the clouds.
Here is a view out my canopy, looking toward Mt. Diablo. Notice that the vario shows -4 kts. Someone told me to always make radio calls in lift so the people listening hear the vario and know what a great pilot you are, to be thermaling effectively while distracted by the radio. I suppose the visual corollary is "Never take a photo of your instruments unless the vario shows lift." Guilty as charged. 'Nuff said.
|Looking out the front in N301YC. 4600 feet in -4 kts of sink, at about 48 knots (should be faster in sink!)|
I was having a LOT of fun, but then remembered that I had a date Friday evening and needed to be home by 6-ish, At that time I was up around Funny Farm, above 5000 feet, and there was strong lift almost everywhere! So I put the nose down, kicked it up to just over 90 knots, and skedaddled back to Byron.
What a blast!
Stay tuned for Part II, covering the work day and soaring on Sunday March 30.