Sunday, January 21, 2007

Good January soaring

A cold front went through on Thursday, and Saturday's forecast looked pretty good to me. Cold air aloft, clear skies and probably heating to 10 degrees above the trigger temp, only a weak inversion forecast at 6000' or so. Driving in, there were some clouds at about 6000' in some valleys, but the Hemet valley was clear. Later I spotted some very concave-bottomed little clouds over "the mesa". Later they looked really choppy, and some people thought they were rotor clouds, as there was supposed to be some strong wind higher up, and we could see lenticular clouds southwest of the Big Bear area. But eventually they formed into full-fledged cumulus. And as the afternoon progressed, nice CU formed in and around the valley, up to about 50% coverage. They just weren't very high - some people said about 4500' MSL.

I took up the PW5 about 2:00. At 3000' AGL I was in clear blue, so I hung on for another 200' and let off nearer to clouds. Sure enough, there was good lift under all the clouds - just needed to find the best parts. I went down a ways and then made it back up to my release altitude. I flew around for my allotted hour and eventually got up to 5000' MSL, and the cloudbase was probably 500' higher. Finally I just sped up to 60 kts to reduce my L/D, and flew around for a while to lose altitude. I landed with a 1 hour and one minute flight. Not bad for January!

Several other ships were in the area. As someone put it, "Not a good day to get very far from the airport." At one point I shared a thermal with a Discus. At another time both of the club Blaniks were circling below me, and I took a couple of pictures of them. Not the best shot, but at least I got them.

It's really hard to fly smoothly, turn to stay centered in a thermal, keep a good lookout, and take a picture! With my digital camera, if I use my left hand, I can't see what I'm shooting. If I use my right hand, I have to fly left-handed, which works OK in a Blanik, but is hard in the PW5 because it's so sensitive.

I mentioned using the Outside Air Temperature display to watch the gradient during tow... I did remember to look at it a time or two, but not often enough to be useful. Maybe next time. I did check it up at 5000' MSL, and it was 3 Celsius. AWOS was reporting dewpoint as 2 C, so since I was just below cloudbase that made sense. That's 37 Fahrenheit - cold up there! I spent just a moment looking at SeeYou Mobile to see if it could display the OAT. I don't think it can, although the data is supposed to be in the feed from the Volkslogger. More to check out.

I plugged my PDA into the Volkslogger, and that worked OK for a while. But halfway through my flight, the PDA shut off. I turned it back on but it never synced up with the VL again. Maybe a setting related to external power. More to check out...

The latest SeeYou Mobile has a thermal strength display when you're circling. It's not clear to me how to use the display... there's an arrow and circles of varying size representing relative lift strength. I'm not sure if the arrow means the compass direction, or the nose of the ship. More to check out... If anyone's used this, please comment.

Tuesday, January 09, 2007

The Lean

My brother is an avid motorcyclist, owning dirt bikes for years and recently a Harley. He mentioned to me an article (or column) titled "The Lean" in a Harley magazine. The author, often asked what was so attractive about riding the road on a motorcycle, distilled it down to "the lean". That is, the fun of riding the curves and the way you have to (get to) lean the bike into the turns.

I think that's part of the fun of flying a glider: the lean (or the bank). We spend a lot of time turning in banks of 30 degrees to 45 degrees or more. That's something that one doesn't experience in an airliner - they tend to keep to 15 to 30 degree banks to keep people comfortable. But you know what? If you're not afraid of it, the lean is great fun!

It's partly the G-force: 1.4G in a 45-degree turn, 2.0G in a 60-degree turn. That's what makes a roller coaster fun, too.

It's partly the visual: the earth passing by sideways... the wing pointing down at the ground...

Turning a car around a flat city street corner is not the same... centrifugal force pushes the car away from the turn and does not feel natural. Taking a car at speed through a properly banked mountain curve or freeway ramp invokes "the lean" and is much more satisfying.

Sunday, January 07, 2007


Today I was thinking about the temperature inversion that was forecast for yesterday. Each flying day as I'm preparing, I look at (among other things), the atmospheric temperature forecast from NOAA's NAM site. The closest forecast to Hemet is for San Diego (I think Miramar NAS), so I don't quite believe it, but it's the best I can find. If an inversion is forecast, then I don't hope for too much out of the day.

Sometimes I can see evidence of an inversion, a haze layer with a defined top. Sometimes it seems to correspond to the forecast inversion top, but I've never paid too much attention. I've sometimes wondered whether the inversion develops locally as forecast. The local commercial operator could, I suppose, take temperature soundings as they tow or go up for a morning checkout flight, but I don't think they do.

Today it hit me. Duh! The PW-5 can display Outside Air Temperature (OAT) on its flight computer LCD. It displays in degrees Celsius, just like the DUATS and NOAA sounding forecasts that I use for my daily thermal forecast. I've never used it, I leave the computer set to display average lift. But I could use OAT to confirm or refute the sounding forecasts during my climb! So... I should pay attention to the forecast temperature gradient, and then keep an eye on the OAT during the tow. That should tell me whether there is or is not an inversion... whether the air is or is not stable.

Anyone else do this?


I can't believe it's already been two years since I achieved my Private Pilot certificate. But since it has, it's now time for a Flight Review. FAA regs require all pilots to have a Flight Review every two years, so we call it a Biennial Flight Review (BFR). It requires an hour of ground instruction and an hour of flight instruction, or in the case of a glider, three flights of at least pattern height. It's with an instructor, not an examiner, and it's not a pass/fail thing, it's more of an educational thing.

The day was clear but not soarable, so many club members were doing checkrides and signoffs of various kinds... our club requires a single checkride with an instructor at the start of each year, and I think CFI did four of those along with my BFR. And student pilot JD got signed off for his written exam. Quite a busy day.

I had not flown with this CFI for a long time. He asked me if I'd had any good flights this year, so I told him about Minden (10,000' in 10kt lift and sink), Tehachapi (silver distance but not logged, 15,000') and San Jacinto (10,500' under CU right here in Hemet). I think he was pretty pleased with my progress. He had also flown a Grob 103 at Minden.
  • First flight was to be 2000' AGL but of course he pulled a rope break.
  • Second flight was to 2000' AGL or so, I just flew around and did some turns and stuff. Not a hint of lift. Too stable... there was an inversion forecast up to about 6000' MSL. I undershot the landing... should have closed airbrakes some on final.
  • Third was a pattern.

I asked him if he had any comments or anything... "Nope, you're good."

Monday, January 01, 2007

Passenger flight

My younger daughter N wanted to go for a flight for her 19th birthday, so we went out on Saturday. The forecast was mixed... it had the potential to be a good day if it heated up enough. We took off about 1:30. I flew from the back seat to give her the better view. No one was reporting any decent lift, so we took a 4000' tow to ensure that we'd get a decent flight time of we didn't find any lift. We found a little bit of 1-kt lift late in the flight, not enough to sustain us. So we ended up with 27 minutes... a bit more than a sled ride but not much.

Critique: The variometer in the back cockpit only goes up to 5 knots, so on tow I found myself looking around her head to see the one in the front seat. This proved to be a bit of a distraction. Just as I was getting ready to release, after visually clearing left and right, I noticed I was a bit out of position high, and lost sight of the towplane. I nosed down a bit, caught sight of it again, and released immediately.

On final approach, I seemed to be a little high at the last minute, rounding out very close to the start of the landing box instead of well in front of it. Again, I think the view from the back seat is a little limiting, and I think I was looking around her head to the right and left for alignment, instead of having a clear straight-ahead view. So I kind of fixed on my aiming point incorrectly, and ended rounding out AT it instead of BEFORE it. That has not been an issue on previous flights from the rear seat. But it all worked out... we didn't float very far, and touched down and stopped well within limits.

Blog format changes

I just added the new Blog Archive element to the right-hand pane. This makes it a lot easier to go back and read the old stuff instead of having to step backward 10 items at a time. It seems to work great. Please let me know if you notice any problems.