Friday, May 31, 2013

The Mallettec Mini Vario

"What's that thing on your hat?" people occasionally ask. It's the Mini Vario from Mallettec. I've had one for a long time - I'm not sure just when I bought it. I'm writing about it today just because I finally had to replace the batteries after 6 or 7 years.

It could not be much simpler. It has a small but mighty clip on the back, so you can just clip it to the edge of your hat next to your ear. There's an on-off switch on the back. There's no volume control.

The unit beeps to let you know when you are in rising air (i.e. air pressure dropping). The rate of the beep varies with the rate of pressure change. It is silent in sink (pressure rising). It is so sensitive that it changes if I hold it in my hand and raise it over my head. There's a very tiny adjustment screw, in case the beep rate is too fast or slow, but I've never had to use it.

I originally bought the Mini Vario when I became aware of the safety benefits of audio varios, and I was flying a lot in Blaniks with no electric devices at all. I still use it as a backup or a cross-checking device.

One of our ships has an audio vario system but the static plumbing is sometimes flaky. We have not been able to find the problem, but I suspect it has to do with moisture in the lines. If I don't believe what the vario is telling me compared to the altimeter changes or the feel of the air, I turn on the Mini Vario to break the tie.

I really believe in having backups for systems, because they have saved my neck a few times. In my first contest - one of my first cross-county flights - the battery totally failed, and that ship only has an electric vario. So the Mini Vario really saved the day.

My only complaint is I wish it were a little louder, or had a volume adjustment. If the wind noise in the glider is loud, it can be a little hard to hear. Other than that, it's a terrific little device and I almost never fly without it!

Monday, May 27, 2013

Back in the Air after Refinishing

I have not posted since early March because... I have not flown since then. Our Grob 103 Twin Astir has been out of service in order to have the top surface of the stabilizer and elevator stripped and refinished. It was peeling very badly, so we took it out of service between the late-winter BFR season (it seems several of us have our BFR dates in January-February), and the start of the good soaring season.







The stabilizer was peeling, but that's not quite the right term for what happened to the surface of the elevator - disintegrating is more like it! Over this winter, the surface really just started crumbling before our eyes.

We chose a shop in Tehachapi to do the work. Getting the stab there and back was a bit of a trick, because it is is 10.8 feet wide. That's too big to fit in my full-size pickup bed, which Pythagoras says is 8.9 feet diagonally. Letting it hang out over the tailgate or stick up over the cab seemed like a recipe for disaster. So one of our club members put it in his camper, which allowed it to go over the cab and be protected.

To bring it back, I decided to put it in the glider's trailer, since there's a nice padded pair of brackets for just that purpose. From home to Crystal (to get the trailer) to Tehachapi, back to Crystal and back home is about 320 miles, so retrieving and installing the stab a couple weeks ago was an all-day affair. It looks great! As it turns out, the surfaces had been reworked but not stripped before, so this time two or three layers of material were removed. The elevator is now measurably lighter, so it should be somewhat more responsive.

Then the ship was due for its annual inspection. Fortunately nothing else major came up, so last week it was signed off as airworthy again. This Saturday several of us spent the morning lubricating all the control linkages, washing the ship, putting a coat of wax on it (gotta protect that new finish!), polishing the canopy, and doing general maintenance required for a ship that sits out all the time.

Since significant maintenance had been done, a solo test flight is required before any passenger flights would be allowed. That job fell to me, so I took it up to 1,000' AGL for a quick checkout. On takeoff, I  PIO'd it a bit, recovering after the second oscillation - maybe the lighter elevator made it react more quickly? Or maybe it's just that I haven't flown for a month and a half...

One of the fellows who came out this weekend is a former club member who is looking to rejoin. Recently he has been signed off to fly in high-performance gliders and at Crystalaire, so now he will need to get a checkout in our Grob 103. I took him up for an orientation flight so he could start to learn the specifics of this ship. I let off tow in lift over the "second ridge", and between us we took it up to about 8,700' MSL a few times. We landed after exactly one hour.

Another club member who hasn't flown much lately wanted to get some practice before tackling his BFR, so we went up again. This time we got a-l-m-o-s-t to 10,000' MSL. We headed over the the area near the top Mt. Lewis, expecting to find some thermals popping, or wind blowing up the sides of the "bowls" between the mountains. Nothing. It was weird - way calmer than we usually would find up there.



Back down below the second ridge, we found some more lift, but not quite as high, and then out over the desert we found some marginal wave lift. There was a fairly strong wind out of the west, and weak wave had been reported there a couple of hours earlier, and sure enough it was still there. That gave us enough time for him to practice stalls, slow flight, etc. which might be requested during a BFR flight. We came in after exactly 90 minutes.

So... I flew for 2 hours and 40 minutes, but since I let the other pilots do much of the flying, I only get to log 50 minutes. But it was really great to be back in the air again!

Tuesday, March 12, 2013

Flight Review

It's been quite a while since I have posted... and over two months since I have flown. January weekends were busy with family and organization commitments, and the weather was not so great. Then in February we had a death and two births in my immediate family, so weekends were again taken up. Lots of stuff happening with our soaring club, though... repairs, moving and working on equipment, and making plans for the future.

Private pilots need to have a "biennial" Flight Review (what we call a BFR) every two years, and mine expired in February. Another pilot and I scheduled ours for this weekend. It consists of an hour of ground instruction/quizzing, and an hour of flight instruction or three takeoffs and landings. The weather forecast was iffy for Saturday, with possibly high winds, but we all went up to Crystalaire hoping for the best. By the time we finished the ground meeting, the winds were 10-12 knots, pretty well aligned with the runway, so it was not a problem at all.

In the ground portion we talked a lot about emergency procedures, aeronautical decision making, and reviewed several serious accidents (one of which was a fatal crash by a friend of ours). We spent some time talking about optimal bank angles for minimizing altitude loss (45 degrees is best), and how that applies to low-altitude turns during  rope breaks etc., and how it applies in thermalling.

The other pilot decided he was not ready to do the flight portion of his review this day (he's not flown much lately), so the rest of the day was mine. I had never flown with this instructor before, so I was a bit nervous. It's not a pass-or-fail test, but it is still a critical review, and I always want to do well.

Flight #1 was a 3000' tow. I demonstrated imminent stall signs, and immediate recovery from stalls. We did several steep turns and measured the altitude loss, to confirm what we had discussed on the ground. When we were preparing to land, another glider had not cleared the runway and I had to discuss options for avoiding it. My plan was to overfly it and land long, but while we were on final approach the glider cleared out and we landed normally.

Flight #2 was a demonstration of tow plane signals which ended up with a downwind landing.

Flight #2 was intended to be a demonstration of a modified pattern, but based on our position relative to the field (and a too-hasty decision), it turned into a demonstration of a slip to a downwind landing.

My takeoffs, landings, stalls and turns were very good, but some of the other aspects of the flights resulted in some feedback from the instructor - that's why we do these reviews! We exchanged emails later that night to recap the day.

After we were all done, the other pilot and I removed the stabilizer from the ship. It has some significant  peeling and flaking of the top surfaces, so we are taking it to a shop to be refinished. That should take about two weeks, so we should have it flying again by early April.

Saturday, December 22, 2012

Mind the gap!

Some places, that means "don't fall in the gap between the platform and the train." In soaring, that means "don't get trapped when the Foehn gap closes under you." I've learned about it in training and read about it, but never experienced it until today.

The RASPtable forecast showed possible wave from a southwest wind. The NWS forecast showed increasing cloudiness after noon in the high desert. Both were spot on! When I arrived at Crystalaire there were lennies far to the west, but it was clear overhead. By the time I was ready to fly, wispy wave clouds were starting to form over the local mountains. I had to wait quite a while for the tow, and we watched rotor clouds forming over the foothills, and increasing wave clouds over the mountains.




I launched at about 12:45 and there was only moderate rotor turbulence on tow. The tow pilot did a great job of dragging me right into the wave lift. When things got smooth, I let off at 7,800 MSL, which at 4,400 AGL was quite a high tow for me. But it worked! I worked the wave back and forth a bit, trying to find the strongest part. It did not form a very long line, and I had the best luck staying pretty stationary over the Devil's Punchbowl and facing into the wind. I bet my groundspeed was only 5 knots.

For quite a while, the only clouds were over the mountains. By the shape of the bottom sections, they were clearly driven by wind, but the tops were not smooth like classic lenticular clouds. There was some wind shear, with Hemlholtz waves visible occasionally. We had rain earlier this week and the mountains were dusted with snow, though not as much as I expected. There were a couple other gliders exploring the wave, but not very close to me. I eventually got to 12,200' MSL, much better than I expected today!




Secondary wave clouds started forming behind me over the desert. Initially they were pretty rough but eventually turned into classic lenticular clouds. Look how smooth the top of this one is. They look like static formations, but if you ever get a close look at the upwind edge you'll see it is constantly forming as the wind moves moist air up into it, and on the downwind edge it is constantly dissolving as the wind pushes the moist air down and it re-evaporates. The smooth top indicates the boundary of fast-flowing, condensed moisture.  You can see a gap called the "Foehn gap" between the trailing edge of the clouds over the mountains, and the secondary clouds over the desert.

The "standing waves" appear to keep the clouds in pretty much the same places for quite a while, but in  fact they are constantly evolving. The gap in the previous picture disappeared at its western end, as the two clouds merged. Over about a 5 to 10 minute period, that gap got smaller and gradually closed to the east - picture a zipper closing, with me as the pull-tab! I spotted it happening pretty early on, and headed east at a pretty good speed. I was actually higher than the clouds, probably by about 1,500 to 2,000 feet. I suppose I could have hopped over the northern (secondary) wave, but what if it developed even more to the north? So I continued east (in moderate lift, not losing altitude) until I was clear of it. This picture is looking back from where I came. See the narrow gap in the middle of the picture? That was much bigger 5 minutes earlier! I had heard about this phenomenon, so I was prepared for it, but I had never seen it in action.


Along the way, I saw a "cloud bow", a bull's-eye-shaped rainbow in thin clouds below me, with the sun behind me in the opposite direction. I tried to take pictures of it, but I only had a few seconds - and I was concentrating on getting out of the gap - so they didn't come out very well.


You can see the huge difference in cloud cover between picture 1 and picture 4. That cloud growth occurred in about 45 minutes! And hmm... now the cloud was covering the airport! If it grew much bigger, I'd be stuck above the clouds far from the field. I decided to duck under the cloud so I could be sure of getting back, even if that meant cutting my flight short. At this point I was still close to 12,000' MSL, and the cloud base was probably about 8,000' MSL, so I had a lot of altitude to lose. By a combination of speeding up to 80+ knots, and using spoilers, I got down under the clouds. But I had to fight quite a headwind to get back to the airport, which cost even more altitude. I didn't get very low, but low enough that I did not have much altitude left for exploring.

A couple of other gliders and I explored the area to the west of the airport, trying to reconnect with the lower part of the wave. It was there, but not wide enough or strong enough to let me go southwest far enough to really reach the leading edge of the cloud. So I eventually landed after just over an hour. By this time the clouds were covering 70% to 80% of the sky - just like NWS had said.

All in all, a very satisfying, interesting, and challenging flight.

Saturday, September 29, 2012

How can there be lift EVERYWHERE?

I haven't posted for a while, though I have flown. Things have been pretty busy... I'll catch up on some recent events in the next post (I hope).

Today's forecast looked good, but with one caveat: NWS listed "broken cirrus" starting about 2:00 pm. "Broken" is a technical term that means more than half the sky. If that much cirrus came in, it could shut down ground heating. The soaring forecast showed a convergence of winds right across the top of the San Gabriel mountains - that would be good! Driving up from the south about 9:30, I could already see clouds right on the top, and it was way to early for them to be CU from thermal heating. The local instructor I usually check with said they had had great conditions for the last two weeks, and expected more of the same today.

I prepped the Grob 103. The gliderport was hosting a bunch of Boy Scouts flights... between those, a down towplane, a wind shift which meant towing six gliders to the west end of the runway, and a line mixup, I didn't launch until 1:45. Fortunately the cirrus was staying scattered. The lower clouds looked great - more over the mountains than the desert, and cycling fast enough you could tell new ones (good lift) from old ones.

On tow, we had an "event" - I don't know if you'd call it a close call or not. After takeoff we did a 270-degree turn to head south. That took us over the downwind leg for the opposite-direction runway. Fairly abruptly, the towplane climbed, not the typical flying-through-lift jump - and I had to catch up. Looking down, I saw a glider on downwind leg about 100-200 feet below us. I don't know if it caught the tow pilot by surprise and this was "evasive action" or whether he had him well in sight... but it was closer than I've ever come to another glider while on tow.

I let off at 2700' AGL (6100' MSL) in good lift. I found good stuff right away, and took successive thermals up to 8,000, 9,500, and then 10,600 over the mountains. I overflew Mt. Baden-Powell, then went chasing ever higher clouds.
Some like the ones above looked nice and sharp on top, which indicated they were growing and would have lift underneath. But they were cycling so fast that they died before I got to them.

In the next pic you can see I'm close up under some smaller ones. The trick was to look for wisps of moisture that were just starting to condense, and quickly get under them.






The highest I could get was about 11,000 MSL under these clouds. I very rarely hit any serious sink between patches of lift. Eventually I headed out over the desert and... the lift got even better. Away from the mountains, with their moist lift, it was all blue, but there were long straight stretches that I assume were convergence lift. I went probably ten miles straight north and was usually in zero sink or minor lift. Eventually I reached some little lakes and I was still at 10,000+. Then... I hit even MORE thermal lift (with no cloud to mark it) and worked that up to 12,500! This was probably the first time I've found a higher lift ceiling over the desert than over the mountains. It really felt like the lift was EVERYWHERE today. That's not usually possible - what goes up must come down - but if there was a large-scale convergence due to the south wind coming over the mountains, colliding with the mild offshore wind that was building, maybe there was a widespread general uplift in addition to the great thermals.


I decided to come in after about two hours of great flying, and had to use spoilers to get down from 10,000 feet! As I got down near our "report-in" altitude of 5000' MSL, I could see there was a glider staging for takeoff, and a glider on the radio was getting ready to land. Now usually, we have limited ability to go into a "holding pattern", but as I circled just to the west of the airport, I found a wide, gentle thermal. I held there for 10-15 minutes while one glider took off and three landed - and I had gained 1,500' without even trying. Highly unusual!

I ended up with a total flight time of 2 hours and 25 minutes. Everyone I talked to on the ground agreed it was a terrific day for lift.