Sunday, March 30, 2008

A little local dolphin flying

Saturday's weather was better than I expected, with nice scattered CU's from about noon until about 2:30, though not high enough to go very far from the airport. I took fellow pilot N for a ride in the Grob 103 - I did all the flying, he helped with lookout and strategy. As it turned out, I should have listened to him more.

We let off at 4200' MSL (2700' AGL) in lift under a cloud. The clouds were fairly constant to the north, and we were able to "dolphin fly" a few miles. That means that there's enough lift, and the sources of lift (generally marked by clouds) are close enough that you can fly straight and stay in lift, without stopping to circle. When you're in lift, you slow down to minimum sink speed in order to stay in it as long as possible - ride it as high as you can. Then when you get out of it, into neutral or sinking air, speed up to get to the next lift as soon as you can. So you end up going up and down like a dolphin. (Not at all the same thing as "porpoising," which is an uncontrolled up-and-down pitching - also known as a pitch PIO. Go figure.)

To stay clear of the clouds, the highest we could go was 4600'. When we reached the north end of this little cloud street, we headed southeast across the Hemet valley, moving between more scattered little clouds. We found that the lift was weaker, more narrow, and ragged. No more straight flying, we had to work the thermals, and could not get up to cloudbase as well. N kept telling me it was probably better to the west (over the hills). After getting back near the airport, we headed southwest to try to work some more lift, and didn't find anything useful. Soon we were back down to pattern altitude and had to come back in for a 36-minute total flight. Disappointing, since things were working, and others had longer flights.

The lesson sfrom this flight (seems like there's always a lesson) are:
  • The clouds over the valley were obviously more ragged, less well-defined, than the ones over the hills, but I failed to pick up on that fact. For some reason I thought that a cloud was a cloud, or that they were forming there. The valley clouds had no lift under them. They probably formed over the hills, broke off and drifted downwind over the valley, and then decayed there. Should have listened to N - should have bailed out of the valley back to the hills earlier.
  • When I was under the clouds over the hills, all I could see was the bottoms - they were so close together I could not see the tops of the ones futher ahead. The tops probably had the well-defined outlines that indicate growing CU, but I couldn't see them from below.
After we landed, a student pilot and I considered going up for another flight, but by then the cloud cover was getting much more prevalent. With the sunlight to the ground greatly reduced, we figured the lift would not be working too well, and it was starting to get windy.

On the ground, some of the new student pilots are approaching me with questions on weather and various other topics, which is great since I'm working toward becoming an instructor.

Saturday, March 15, 2008

Windy work day

Although I spent the day at the airport, I didn't fly today. Our club had scheduled both a morning ground school for student pilots and a work day. It was a post-frontal day with lots of cumulus, and presumably good lift, but lots of wind. The forecast was for increasing clouds and possible rain in the afternoon. I pretty much planned on not flying because of the work and the weather. We private pilots vacuumed, washed, waxed, buffed, installed, painted (and repainted), took off tires, put on tires, sanded, hauled away... but didn't fly.

On the plus side, after all the recent rains, the field is covered in flowers:



If we had not had work to do, the day would have been flyable. The wind was strong, from the left about 30 degrees. But it was pretty well shredding the clouds, so we figured the lift would be iffy.

The students finally got out of class about 2:00. (I guess there was a lot of wind indoors as well.) The instructor was willing to fly in spite of the wind. He just said "it's a challenging day" and proceeded to train students on crosswind takeoff and landing procedures. Notice how low he's holding the left wing compared to the right:

No longer anonymous

Being in the computer industry, I'm keenly aware of how nothing published on line is private, and how easy it is to find out information about any person by searching the web. From the beginning I have purposely not included the names of other pilots, instructors, or my club. I would not want anything I say to adversely reflect on anyone's skills, practices, or decisions. Let's say I wrote about what a particular instructor said to do, and later an accident or incident occurred that involved those instructions or that instructor... I would not want my opinions to get anyone in trouble. So I've tried to be careful.

I'm sure anyone who really wanted to could put two and two together and figure out who I am and what club I belong to. And then looking at my club's web site, figure out instructors' and even pilots' identities. So maybe trying to be anonymous is not all that effective anyway, but I figured I had to try.

This month my blog and my name were mentioned in AOPA's Flight Training magazine in a follow-up review of blogs. (I had asked the author to consider including my blog in the follow-up article he was planning.) That's a good thing! I hope anyone reading FT and thinking about soaring will read my blog and find it helpful. As the article pointed out, there are very few blogs about soaring... I only know of about 4 or 5, and some of them are not very active.

So now I'm not anonymous anymore. My name is Roger Worden, and I live in Orange, California. I fly with the Orange County Soaring Association, based in Hemet, CA. My blog contains my personal thoughts and opinions, is not on behalf of OCSA, and does not necessarily reflect their views. I've updated my blog profile to make this clear.

I still do not want anything I say to reflect on any club instructors, so I've removed their initials from all previous postings. I believe this is important. I know some of my fellow club members read my blog, so I will continue to be careful what I say about any members and their skills or actions. (I still use pilots' first initials occasionally just to help keep the postings clear.)

I hope everyone who reads my blog finds it useful and interesting. I hope student pilots will read the sections that relate to their current stages of training and find them helpful: to learn what's coming soon, to help explain the why of their training, and to know that others have the same questions that they do. Remember, though... I'm not an instructor. Please discuss any detailed questions with your CFI.

Feel free to add comments or ask questions about any posting, current or ancient. That's the only way I know anyone is reading this stuff, since the blog does not provide any "hit" statistics. And thanks for reading!

Sunday, March 02, 2008

DUATS and DUAT and Mobile

I saw an ad for DUAT Mobile (http://www.duat.com/mobile) recently, a service for phones and Internet-connected PDAs. I figured this would be a great way to get weather and NOTAM and TFR info when in the field. I tried it once from my Blackberry and could not get signed in.

So tonight I tried duat.com from my home PC to see what's up. I have been using duats.com for years (note the "s"). The login IDs are different between the two systems. I guess they are two different providers for the same FAA information. Duat.com seems to be a more modern, graphical system compared to duats.com's primarily textual interface. I'll have to check it out more thoroughly. Once I signed myself up with duat.com, I was able to use the mobile version.

On my Blackberry, the graphical information such as the U.S. TFR map and the Surface Analysis chart are really very readable. I think this may be a great source of information. I'll try to write more after I play with it for a while. Meanwhile, check it out if you haven't already.

Pieces and Parts

Our club just bought two Blaniks and a bunch of parts from a private party. We knew that one of the ships is in really good shape and the other "needed to be assembled". Well, that was an understatement!

Apparently ship #2 was in the process of being totally refurbished. I don't know whether it was damaged, or just needed an overhaul. But it is in pieces. The wings are intact, the cockpit is partially assembled, and that's all. The fuselage and empennage are all apart. There are both old and new (shaped but not drilled) sheet metal for quite a few parts, so we can tell he bought replacements for the rebuilding process. Much of it is in very good shape - the control surface fabric all looks great. But... this would be quite a project to rebuild the ship. The club has not decided what to do with it all. We may be able to put these wings onto one of our club Blaniks that was recently crashed.

But it was interesting to look at the structure and parts as we were sorting through it and putting it all away. For example, I have never had the opportunity to see the interior of the fuselage aft of the rear seat. Handling some of the aluminum fuselage sheets and bulkheads, I was struck by how thin and flexible they are when not assembled. I had started to get some understanding of this when reading some weeks ago about monocoque ("single shell") construction. (Technically, I think the Blanik is "semi-monocoque".) When assembled into a tubular fuselage shape, the sheet becomes very stiff. When the bulkheads are riveted in and prevented from twisting in the third dimension, they become strong and stiff. Very interesting! And certain large parts such as the stabilizers, flaps, and ailerons are extremely light. When assembled, the Blanik weighs about 650 lbs (as we can tell from pushing it around on the ground) but I've never really had a chance before to see just how light these parts are individually. Not a bad way to spend a cold, unflyable day.

Socked In

Yesterday I was planning to take a friend C for a flight. We had already cancelled once before due to high winds. The forecast was for marine layer clouds to burn off by 10-11 am, with 30% cloud cover and a high of 67 to 70, so it should have been flyable. Lack of lift would be fine, because this was to be a first flight for her, and I planned to take it easy (no steep turns) until she said she was OK - I don't like to make people sick.

The clouds never cleared and the temp only got to about 60F. No one flew until some student pattern flights at about 1:00 or so. The ceiling was reported to be 1200' AGL by AWOS. The student flights could not go above 700-800' to avoid busting the 500' minimum distance below clouds. They quit after two flights and we all went home. Bummer for my friend!!

I stepped into the Ground School class to do a 5-minute review of my Weight and Balance session from last week. I had given them an assignment to calculate the minimum and maximum passenger weights that they could carry in the Blanik, with the pilot in either the front or rear seat. About 75% of them had done it. Some picked up on some nuances, which shows they thought it through, which is what I really wanted. For example, with a front-seat pilot, there is no minimum rear-seat passenger weight (or else how would you solo?). With a rear-seat pilot, there is a minimum front-passenger weight - you CANNOT fly solo from the rear seat. I wanted them to have a mental image of what their passenger limits are... if a proposed passenger is well within your personal range, you don't really need to calculate W&B for every flight, only if the passenger is near your limits. Others correctly calculated the absolute maximum limits - some absurd weight combinations such as 65 lbs and 360 lbs. Others found that it is possible to exceed the maximum weight limit before exceeding the CG limits. So I think they really learned the concepts pretty well!