Slope Soaring - This is what you do when you thought it was too windy to fly.

[Todd G]

I wondered what slope soaring was all about. We have plenty of wind here in Idaho, may have to give it a try.

[mclarkson]

I really, really wanna find someplace to give this a shot.

[AEAJR]

Anyone been slope soaring their electric airplanes?

[Old Fart]

Only my E-Hawk

[AEAJR]

How did it do on the slope? What were the conditions? Did you have to add ballast?

[Old Fart]

Did "ok" in ,10 mph winds. It's an e-glider, but like most of them, really targeted towards the thermal folks. I took a 1000 and 1350 mah lipo with me, settled on the bigger (and heavier) battery. Need to do the dual aileron servo mod, single servo systems suck.

[AEAJR]

If you are having penetration issues in that configuration look to add more weight.

On the Radian and Easy glider the wing rod is hollow. We slip a smooth steel rod in there for ballast. The one I typically use does not fill the wing rod, but is about 1/2 the diamater of the rod. Adds about 6 ounces and really improves slope soaring performance.

[Old Fart]

No wing rod on the e-Hawk, but I do have some room for ballast. A buddy of mine has the same plane, runs a 2200 mah LiPo on windy days.

On another note, picked up a used Trinity F3F a few weeks ago (birthday present to myself), it came with plenty of ballast. I can substitute steel rods for the tip joiner, add steel rods to the wing center section and also add slugs into the belly. Takes the plane from 100 oz to 173~175 oz

AND.....my Rodent is almost half completed

[mustang_jmz]

This is what I call a too windy day to fly (70 Km/h of wind): http://youtu.be/BtABlKXqA5M

Other Alpina's adventures in my playlist: https://www.youtube.com/playlist?lis...XZjPdBGeb4uqaD

[Old Fart]

Needed ballast

Nice video !

[mustang_jmz]

That's what tought my wife when she tried to help me holding the glider for launch: she almost took of with the aircraft
scary moment at that moment at that time, very funny by now

[maxflyer]

Since I've just been chastised for not being "beginner enough" to post on this forum, I'm not sure I should chime in, but, in the "beginner builds foamie" thread above, my newest build was actually constructed to take more advantage of the slope soaring I have been doing with my previous "first in ten years model." My site proves that you can slope soar in unexpected places. I live near the top of a long, shallow sloping ridge that rises out of the Rio Grande valley floor probably 10 miles away. The prevailing wind rides up this slope most of the time. You wouldn't expect this to work, as the terrain up this slope is semi-populated, with a series of subdivisions along the way to the top, dirtying up the gradient. As the wind reaches the highest level, where my subdivision is, it is finally hoisted up over a ragged run of Juniper trees. I launch crosswind from a narrow subdivision road that runs along the upwind side of these trees. When I started flying my first little 8 oz. scratch built foamie at this location, one of the first things I discovered after launching up over those trees was this slope flow. The next thing I discovered was that a draggy, lightweight foamie makes a great slope flyer! Then I discovered that 8 oz. airplanes do have a velocity limit when flying this way! I then discovered that this kind of flow will demonstrate how to blow an 8 oz. foamy a mile downwind if you let it! Sooo, my next build, though only a tenth of an ounce heavier, was designed to be a little more smooth and stable in these lift conditions. All this was really what I wanted to describe in my other post...but hey...it's a beginner's forum, and they don't know nothin."

[AEAJR]

Originally Posted by maxflyer

Since I've just been chastised for not being "beginner enough" to post on this forum, I'm not sure I should chime in, but, in the "beginner builds foamie" thread above, my newest build was actually constructed to take more advantage of the slope soaring I have been doing with my previous "first in ten years model." My site proves that you can slope soar in unexpected places. I live near the top of a long, shallow sloping ridge that rises out of the Rio Grande valley floor probably 10 miles away. The prevailing wind rides up this slope most of the time. You wouldn't expect this to work, as the terrain up this slope is semi-populated, with a series of subdivisions along the way to the top, dirtying up the gradient. As the wind reaches the highest level, where my subdivision is, it is finally hoisted up over a ragged run of Juniper trees. I launch crosswind from a narrow subdivision road that runs along the upwind side of these trees. When I started flying my first little 8 oz. scratch built foamie at this location, one of the first things I discovered after launching up over those trees was this slope flow. The next thing I discovered was that a draggy, lightweight foamie makes a great slope flyer! Then I discovered that 8 oz. airplanes do have a velocity limit when flying this way! I then discovered that this kind of flow will demonstrate how to blow an 8 oz. foamy a mile downwind if you let it! Sooo, my next build, though only a tenth of an ounce heavier, was designed to be a little more smooth and stable in these lift conditions. All this was really what I wanted to describe in my other post...but hey...it's a beginner's forum, and they don't know nothin."

Yes, slope has some unique characteristics. And the slope can be a great place to teach beginners as they can get tons of stick time. As long as the wind is blowing from the right direction, you can fly.

We often talk about keeping planes light but under the right conditions slope gliders need to be heavy, sometimes very heavy. There are slope gliders that are carved out of solid rock wood and are amazingly heavy.

Thorn
http://www.rcgroups.com/forums/showthread.php?t=685497)

I often talk about ballasting slope gliders to make them heavier.

[maxflyer]

Yeah, I see the challenge for my situation being in finding just the right sweet point between weight and performance. Too much weight and it becomes a dangerous missile flying out over people's yards and houses (don't ya just hate it when you knock on some neighbor's door to ask for your airplane and find out you just killed the child playing in their back yard?). I don't think I can safely ever give up the motor flying here, though I can think about a folding prop. I would guess a slick model somewhere in the 16-24 oz range might work well here. With the right kind of airframe I could probably handle 10-12 MPH pretty easily. One thing I did learn very early in my "beginner" status, was that I remained more interested longer by flying in search of lift, than in just zooming around with a powered model.

[AEAJR]

The issue is not weight, it is wing loading and glide speed/penetration.

One of my favorite slope gliders is a Multiplex Easy Glider Electric with a motor. Flies in very light lift but will take about 8 ounces of ballast. The motor can save me if the wind dies, and it gives me the safety net to go searching away from the hill to see where the lift might be. I rarely if ever use the motor but it is there if I need it.

However on a recent slope flying day, even with the ballast the Easy Glider could not penetrate the wind. Even using the motor to get out into the flow, when I turned it off, I would just get blown backwards.

Needed something with a higher wing loading for a faster glide.

[Rockin Robbins]

I'm a strong believer that soaring or slope gliding have things to teach about the bedrock of flying that motor driven planes often don't teach. Gliders are pure flying with no cheating allowed! There's no end to the lessons our ocean of air can teach. And those lessons really come handy when flying a powered plane.

[maxflyer]

For some time I never understood how RC flying could possibly be interesting; move a control stick and somewhere out there a small airplane responds? Only after I concocted a couple of motor-gliders out of $5 toy store chuck gliders, and began to hunt thermals from my driveway, did I begin to get it. We are "feeling" that ocean of air, visually, with our aircraft. It' not a logical connection really. Only after doing it for a while does your hand and brain connect. Then comes the "Ah-Ha" moment.