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Mar 25, 2007, 04:15 PM
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Gentle Lady


Spring is in the air. Anticipating endless sunny summer weekends ahead, I joined the local sailplane club and hope to learn all I possibly can about sailplanes in general and Thermal Duration flying in particular.

However my Electra project still has a way to go. I don't want to rush finishing it, but because I enjoy building, I'd like to continue to take my time, savoring each milestone, and let it get done when it gets done. But….. I need something to learn TD and how to fly off a high start or a winch – and the weather is nice already! What to do?

I indicated interest in a Spirit or Gentle Lady for this purpose in club email and the result was a generous offer by one of the club members of his Gentle Lady which he had built from a kit some years ago, but no longer flew. It had seen some use, but was still very much air worthy, and having it meant my Electra build could continue at the same sedate pace.

I took the Lady to the field two weekends ago and more experienced club members advised for my skill level (slow stick experience only) moving the CG and tow hook forward before I made any serious attempts to fly it would be a good idea. So, I brought it back home, made the modifications and took it back to the field yesterday. Had a great day with a total of seven flights with the Lady. All were launched off the club winch. One of the experienced club members did the first flight all by himself. On the second and third, he handled the launch till the plane came off the line and stabilized, then handed the transmitter to me. On the 4th through 7th, he launched the plane and pulsed the winch while I handled the transmitter for the launch and subsequent flight. What a beautiful sight the Lady is floating in graceful circles in the sky!

I was lucky enough to experience thermal lift on my first two flights. I wasn't skilled enough to stay in them and climb to a speck, but I crossed through the bubbles repeatedly and both of these flights were over ten min duration. Quite acceptable to me and it was a generally wonderful experience!
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May 21, 2007, 07:16 PM
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A lift for the Lady!


I’ve flown my Gentle Lady less than 10 times, and those were "as gentle as possible" winch launches performed by others. (I had the transmitter, but they had the footswitch.) I’m hardly an expert, but thought sharing this high start experience might be beneficial to others getting started with similar experience (or inexperience!) levels.

I really wanted to be independent of the club winch and started learning all I could about high starts a few weeks ago. This thread was particularly helpful, especially the last part from post #60 or so on that discusses launching the Gentle Lady with a high start.

Armed with a wealth of information and lots of enthusiasm , I bought 100 ft, 5/16” OD surgical tubing, a few key rings, and a reel meant for storing electrical extension cords. Could not immediately get my hands on a parachute so I opted to start with a simple red-ribbon streamer instead. A hammer, tent stakes, and a few large spikes I already had.

One thing I learned from the thread referenced above is, don’t start too timidly. A wimpy launch can cause a stall and nose dive before you can correct for it. So I resolved to start with at least 50 ft of rubber and 150 ft of twine, pulling it to at least 8 lbs force before letting it go. Bought a cheap fish scale at Wal-mart so I’d have some sort of reference to work against. I highly recommend the scale (~$5). Counting paces or measuring so that you know when you have stretched the rubber to twice or three times its relaxed length is just too imprecise. Knowing the force pulling on your model in pounds is more reliable and reproducible.

A typical recommendation is to stretch the rubber until the force is 3 to 5 times the weight of the model. For a Gentle Lady, this would be 6-10 lbs.

Now, its easy to get excited (or worried) over that first high start launch. However – no need. It was smooth and easy. I started with flat neutral trims and only a little rudder correction was needed to keep it flying straight. The wings and the energy in the rubber took care of the altitude part – big time! There was a slight breeze from the NW and I launched directly into it. Once up, I let it simply fly off the line.

Well, my first high start launch… ever… was a success. It was so smooth and easy that I tried it another nine times this afternoon, and they were all as smooth and easy as the first. I also walked a few more paces on each successive launch stretching the rubber first to 9 lbs and then to 10. I've read that you can go to 14 or 15# anyway, but 10 seems like a pretty good load on that frail, balsa fuselage. I'm a little reluctant at this point to go over 10.

I’ve build a lot of confidence regarding the launch part but realize that catching a thermal and turning a 200 ft launch into a 15 min flight…. That’s another matter. It was a clear blue-sky day here today, no clouds, and I didn’t find any lift. All my flights were short. But I’m pretty green too. There might have been lift, but I just didn’t recognize it. However I went out today looking to gain launch and landing experience and I surely did that!

Next step is to make up a 300 ft length of twine and move the stake ring so as to use the full 100 ft of the rubber. Can’t hardly wait to try it.

BTW, if you are a newbie like me trying to make sense of all the apparently conflicting recommendations regarding high start launches: “Give it a good throw from over your head!” … “Just open your hand and let it go, from eye level and out in front if you like.”… “Point it straight ahead”…. “Point it up 20-30 degrees” …. “45 degrees!” . I think they all work equally well because the 10 lbs pull of the rubber and the vector it sets is going to overshadow any little initial condition you interject in your launch, probably in the first one or two milliseconds of the flight! I ended up with a fairly easy level toss with the nose up a slight 20 deg or so and it worked fine.

The red-ribbon streamer was ok, but I really want to get a parachute that I assume will carry the line further downwind, back toward me, thereby shorting my retrieval walk. (Today with the streamer, the tow hook ring usually landed toward me, about ¼ to 1/3 of the distance of the total rubber + twine length. Not bad, but I think a parachute would be better.)
Last edited by k4kjf; May 21, 2007 at 07:45 PM.
Jun 08, 2007, 03:14 PM
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Nose Repair


Not sure what happened but about two weeks ago my Gentle Lady started an almost vertical dive from about 60 feet and I could not pull her out. She landed straight on her nose. The wing came off as it is supposed to and incurred no damage, but the nose area was a bit banged up. Later I noticed some cracks in the fuse sides that I believe came from the same crash. I think what happened is that the elevator servo mount came loose in a previous hard landing, and I did not notice it. After launching the Lady again, all seemed to go well until about 30 seconds into the flight.

So, I’ve been in a repair mode. The balsa tip could be sanded and reshaped, but I had to replace portions of the front top of the fuse and remake the cockpit cover. It seemed that the very tip of the noise with its multiple, angled surfaces would be tough to cover, so I decided to paint it instead. And, I had none of the blue/green fuse monokote that had been used originally, but I did have some white Ultracote from the Electra build. So… my Lady has a new white nose!

Also took the opportunity to rework the on/off switch mount as it had become loose in the crash. And,I used CA to glue some of the cracks that I now noticed forming in the fuse behind the wing.

All in all, I guess it came out OK. Hope it still flies well.
Jun 21, 2007, 08:15 PM
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Progress...


First, I got a real parachute (instead of just a streamer) for my homebrew high start and it rocks! The walk to retrieve the line is much shorter than it was with the streamer. Actually even though at first I was disappointed with the parachute’s size and light construction, it is doing the job of laying out the line downwind pretty well – nice and straight. The streamer allowed it to pile up more closer to the stake (farther from me).

I’ve got a lot to learn about finding thermals, but am having fun analyzing my feeble efforts by examining the plot generated by a new ZLog altimeter. I set a new PR today! 1201 ft peak and 11 min duration off a 241 ft high start launch. I got nervous and bailed out twice by putting the plane into a dive. And beause it recovered a bit by itself, seemed to indicate that the CG could still stand to be moved a little farther back…. If I am doing it right.
Jun 21, 2007, 09:38 PM
Life is Good!
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That's pretty cool. Congrats on your thermal!

~Tank
Jul 12, 2007, 11:34 AM
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New Empennage


Thanks Tank...

I’m gaining good experience flying the Lady off the high start, but there is a warp in the stabilizer/elevator assembly that I’d like to get rid of. If I trim so that the elevator at the right tip is absolutely flat, the tip on the left side is about 1/16” above neutral. And of course if I set the left tip flat, the right tip ends up about 1/16” blow neutral. I suppose that warp causes a tendency to turn and that I’m compensating with rudder trim.

I’d like to get rid of that complicating factor so it doesn’t bias what more I learn about trimming in the future. I tried warping it back to straight using a heat gun, but was not successful.

So, instead, I made a new tail assembly – stab, elevator, rudder, and fin. First I was only going to make a new stab and elevator, but decided that when I actually cut the old tail pieces off, it will be hard to salvage the rudder and fin for re-use. So made them new also.

I’m not ready to interfere with summer flying opportunities though, so will probably start the actual change out later in the year – a good winter project. I did cut the hinge slots, but will wait with covering – just in case something changes…


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