An noob's guide to slope soaring

Foam Addict

Squirrel member
Hey all,

Over the past 2 months, I have fallen in love with slope soaring on the hill behind my campus. I have been flying with a heavy, draggy, floppy 8 foot wingspan 3 channel glider I made. This thread is to post my experiences and hard learned lessons about slope soaring. I'll start out with 3 basic rules for any slope soaring site.

1) It needs to have a steady source of wind.
2) It needs to have a fairly steep rise facing the wind. (Round hills are awesome for this, as they always face the wind.):D
3) If you want to enjoy it, it should be easy to climb. :p
The hill behind my Campus is wonderful as it meets all three of these criteria:

IMG_2720.JPG

One really nice thing about sloping is that you can fly almost anything if the wind is strong enough, but to start, a stable glider with a long span is probably the most forgiving, and they can usually handle quite a bit of wind if they have to.

IMG_2830.JPG

Once you have found your plane and your slope, flying it can be a real challenge at first, so here are 3 more guidelines that proved indispensable to me as I learned.

1) Always turn AWAY from the slope! This diagram from Sig shows the general pattern most sloper's stick to:

SIGRC63P97.jpg

2) When in doubt, keep the plane above eye level. This can save you from a long hike if you lose lift without a motor.

3) Keep the plane in front of you, and stay over the up slope. When the wind passes over the crest of the hill, it will drop sharply, creating turbulent downdrafts known as rotors.

The lift lies along the hill in 3 stages. The first is rather weak lift that occurs close to the hill and near its base. This probably isn't enough to keep you aloft, so avoid it unless you are desperate.

The second is the sweet spot, its generally strongest over the higher middle portion of the hill, but can be found almost anywhere with sufficient altitude (6-30 ft agl).

IMG_2856.JPG

The last is an area to be avoided at all costs, even with a motor glider. The rotors will often cause a stall if the aircraft is flown into them with insufficient speed, and will definitely try to drive your glider to the ground.

Untitled.png

The catch is, in order to land, you will occasionally have to fly through these at high speed, then dump as much lift as possible before landing. (spoilers are nice here)

That's all for now, I'll keep updating this thread as I learn more about Aircraft designed for the slope, Mean time, I hope this is helpful to someone out there who's looking into slope soaring.
 

eagle4

Member
nice write up mate. i've never tried slope soaring but it looks like a nice relaxing way to spend an afternoon
 

meehan

New member
Nice write up. Slope soaring is a lot of fun, slope combat even more so. You motivated me, I am going to get some of my old combat wings back in shape.
 

wz31857

Junior Member
slope soaring ballast

I am also a noobie to Slope soaring,I have just returned to RC after 30 years. I built a Zagi 48 combat and made a futile first attempt in 17 to 20 mile an hour winds. I have since spent time dialing in the plane trimming ,cg ect. My question ,is there a ratio of higher the wind equals more nose weight I tried flying in pretty high winds and it just acted like a pie plate in the wind.This may be an impossible question because all planes are different but basically do slopers add weight when the wind speed increases. Thanks for any responses.
 

ztoon

Gone with the Mistral
This may be an impossible question because all planes are different but basically do slopers add weight when the wind speed increases. Thanks for any responses.

Hi,
Basic answer = yes
As english is not my language, I prefer you have a look there, particularly the last picture for more info.
 

JohnC

Member
Yes, I agree, make it an article.

I love slope soaring. I have a hill within walking distance from the office I live in (I'm an engineer near silicon valley). It does not meet the criteria that Foam Addict has laid forth.

Rather than be a singular round hill, it has a West facing slope, with another, lower, North facing slope at 90 degrees. behind that a gully that transitions into a nice bowl facing SW, and behind that a round hill that faces generally south. Add to that a Saddle that faces West.

The Hill.JPG

So it can be complicated. But with a variety of models stacked in the back of your car, and patience, it can be very rewarding. It's major selling point is that it's close (I can walk), It's clear (no trees on the slope).

I fly a UMX Radian, UMX ASK-21, Stryker,Zagi Hp and Radian Pro there.
 

mjcp

Senior Member
(They say) Gliding is the purest form of flight... so RC gliding must be the purest form of Gliding... and slope soaring must be the purest form of RC gliding ;)

Coincidently: just posted some slope video here



mjcp
 

pressalltheknobs

Posted a thousand or more times
Yes, I agree, make it an article.

I love slope soaring. I have a hill within walking distance from the office I live in (I'm an engineer near silicon valley). It does not meet the criteria that Foam Addict has laid forth.

Rather than be a singular round hill, it has a West facing slope, with another, lower, North facing slope at 90 degrees. behind that a gully that transitions into a nice bowl facing SW, and behind that a round hill that faces generally south. Add to that a Saddle that faces West.

View attachment 52500

So it can be complicated. But with a variety of models stacked in the back of your car, and patience, it can be very rewarding. It's major selling point is that it's close (I can walk), It's clear (no trees on the slope).

I fly a UMX Radian, UMX ASK-21, Stryker,Zagi Hp and Radian Pro there.

Love how you have "Crash Site" marked on the map :)
 

JohnC

Member
Love how you have "Crash Site" marked on the map :)

That is from a graphic I did for the blog. The launch site is about 4 ft below the highest point on the hill. So looking South, there is a rim. I'm learning how to land the Radian Pro with Crow. Trouble is, I'm using the DX7s radio, and the mixing is not exactly what I want . . . I did say I'm learning. To go from clean to crow, I have to flip two switches, the flap and the mix switch.

What I really need to do is learn how to fly with flaps and how to trim it out with the elevator so that going into flaps only slows the plane and doesn't drop it.

That way I can go to flaps as I go downwind, do the turn, then flip one switch to go to crow for landing.

The landing pattern is over the crest of the hill, so if I'm not actually over the crest, but behind the crest, I can lose the plane in the SW Facing Bowl. I've only lost the Radian Pro there once. It was ah . . . a huge learning experience.

I had to learn how to restore the plane.

Supporting Fuse for Glueing - 0.JPG

Completed Fuse Restoration.JPG

I have a lot more pictures in my blog about this restoration. It's a Radian Pro, and I didn't want to just slap it together.

I do plan to buy a spare parts so that I be prepared and not lose flight time for restoration.

But I'm done with the restoration and I'm ready to take it out again . . . yay!
 

mjcp

Senior Member
Do you have the crow on a slider or switch?

If on a switch, I think you will struggle:

In a full size glider (on approach) you use the elevator to control speed (to avoid the stall) and speed brakes/spoilers to control rate of decent. (Its not unusual to have them full extended for most of the decent).

I see a LOT of RC pilots using the elevator as the control for rate of decent... By the sounds of it, you are applying Crow, but haven't put a delay in (4 seconds worked on my DX6 in the flap settings to keep things predictable) and need to add some elevator as a mix. THEN use throttle/elevator as above to control your landing...

OR

If gliding is becoming your thing... set it up more like a sailplane:

Use a flight mode to make the throttle stick your Crow control and disable the throttle. (You can always set an "Oh ££$%" button to give you a throttle/motor flight mode on tap if it goes pear shaped). With this setup, you glide the approach, adding Crow to control your rate of decent and elevator to control speed. If you need to extend your landing point... Crow in/nose up (but watch the stall) If you need to penetrate the head wind... nose down/Crow in. If you need to land shorter, Crow Out/nose up (the nose up is counter intuitive but works by slowing you down, so less distance covered... BUT you then need to trade height for speed vertically with extra Crow... but watch for the stall!)

You will notice the word STALL a lot above... many more scale gliders have a tendency to stall on approach and need more height to recover than most power craft. If you search glider tip stall you will find lots about it... it isn't really a tip stall so much as a traditional stall where one wing drops. There are lots of contributing factors but the basic reason is the airflow stalls over the wing due to either airspeed or angle of attack... same as any stall.... so keep the speed up (by use of elevator).

n.b. Just looked at the Radian pro's wings and they are nice and thick at the tips so stalls should be less of an issue. If you move to high aspect ratio wings down the line... you have been warned ;-)

mjcp
 
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JohnC

Member
Thanks MJCP,

I'm just learning to fly and 'The Hill' I describe presents challenge. But it's really close, so I'm working it all out.

My dream is to get back into slope soaring and be good enough that I can fly 'The Hill' with a really cool sailplane like the one in your video.

I have a DX7s and it was a real problem trying to find the mixes to get Reflex, Camber, and Crow for the Radian Pro that will work with this radio. ParkZone support finally found a Word Document that I could use to set up what I have - See: View attachment Radian Pro DX7s Setup.doc

It's not great, but it's a start. I have so much to learn, I'm trying to take it in stages.

My first stage was just trying to see if crow would slow the plane down for a landing. The Hill only has a narrow band of earth that slants down from the crest (Top) of the Hill. That's where I launch from, with about 50 ft of this band between me and the Top, and about 100 feet away from me.

I try to come in over the Top of the Hill (on my left when I face the slope), then land along the band (to my right as I face the slope). The challenge is that there is a lot of turbulent lift over the top of the hill. If I go beyond the top, then I'm over the SE Facing Bowl. On a lot of the approaches, there is so much lift, I can't bring it down. If I put the nose down and the lift suddenly goes away, I don't have time to react. I don't have enough time for my skill level at this point, but that's why I'm learning.

And, of course, I'm landing cross wind. :(

If I don't get it down, I can just turn to the left, and I'm back over the slope with lots of room.

I'm focused on looking for calm days where I can practice. I need to learn how to control a sharp turn between me and the top of the hill, with the plane about 15 feet above the ground with crow on, and throttle off.

The settings require that the flap switch be in the 2 position and then the mix switch moved to the 1 position. The amount of crow is controlled by the knob. All of this is hard to do when I'm trying to do a sharp turn and find a specific height and only have 30 or so feet to do it in. Elevator is mixed in with the crow, so when crow is on, I have to pull the stick back to level the plane.

I'm also learning about mixing. I might reverse the elevator mix with the crow and set it to raise the nose slightly when crow is applied. I could then use throttle to control my descent.
 

mjcp

Senior Member
Thanks MJCP,

I'm just learning to fly and 'The Hill' I describe presents challenge. But it's really close, so I'm working it all out.

My "local hill" is an hour away... Doh!

I have a DX7s and it was a real problem trying to find the mixes to get Reflex, Camber, and Crow for the Radian Pro that will work with this radio. ParkZone support finally found a Word Document that I could use to set up what I have - See: View attachment 52669

Its complicated! not keen on using a dial to do the crow that's for sure! Fiddly and small movements = big changes!

My first stage was just trying to see if crow would slow the plane down for a landing. The Hill only has a narrow band of earth that slants down from the crest (Top) of the Hill. That's where I launch from, with about 50 ft of this band between me and the Top, and about 100 feet away from me.

I try to come in over the Top of the Hill (on my left when I face the slope), then land along the band (to my right as I face the slope). The challenge is that there is a lot of turbulent lift over the top of the hill. If I go beyond the top, then I'm over the SE Facing Bowl. On a lot of the approaches, there is so much lift, I can't bring it down. If I put the nose down and the lift suddenly goes away, I don't have time to react. I don't have enough time for my skill level at this point, but that's why I'm learning.

And, of course, I'm landing cross wind. :(

If I don't get it down, I can just turn to the left, and I'm back over the slope with lots of room.

I'm focused on looking for calm days where I can practice. I need to learn how to control a sharp turn between me and the top of the hill, with the plane about 15 feet above the ground with crow on, and throttle off.

It can take a few goes to get your eye in each trip to the hill.. don't be afraid to "go around"... the great thing about ridge lift is it doesn't often run out on you like a battery flight pack will !

You're right to avoid the rotor on the back and even the top of the hill... its nasty.

Re cross wind... Google glider slipping (n.b. I was taught it was called side-slipping, but it seems there are two kinds of slip and my version is known as forward slipping), you may find its also a good way to bleed height/speed with the added benefit of pointing the nose more towards the wind.

In this video the glider uses no spoilers until a few feet of the ground:

https://youtu.be/hTF3M80d27Y

This is a good video about slips: https://youtu.be/03LJjg5eBak

A side slip is where you cross control rudder and aileron and use the elevator to control your rate of decent. It can be used to compensate for strong cross winds or if your spoilers are not working.

(as with any advice, your mileage may vary and you should experiment a 3 accidents higher than the ground!)

You could try doing a few approaches parallel to the ridge and watch to see what effect all the controls have on your decent rates. Aim for a "touch down" point say 50-150 feet out from the ridge, but at your level. Make your approach the same route you would normally do and see if you can repeatedly fly the displaced circuit, making the same crossing point (displaced away from you) each time.

You can then start to see if its easier to control with crow/sideslip/flaps/elevator etc as you aim for the "touchdown" zone each trip. The good news though, is you have plenty of lift and altitude to recover if it goes belly up! Once you get the repeatable circuits down in lift, you'll be less worried about looking at the sliders/controls and can focus on reacting to the gusts/turbulence near the ridge.

The settings require that the flap switch be in the 2 position and then the mix switch moved to the 1 position. The amount of crow is controlled by the knob. All of this is hard to do when I'm trying to do a sharp turn and find a specific height and only have 30 or so feet to do it in. Elevator is mixed in with the crow, so when crow is on, I have to pull the stick back to level the plane.

Why the sharp turn, can you do a dog leg turn instead by extending the approach? Sharp turns near the ground should be avoided :)

I'm also learning about mixing. I might reverse the elevator mix with the crow and set it to raise the nose slightly when crow is applied. I could then use throttle to control my descent.

If you need to stick back once the mix comes in, the mix needs tweeking... reduce the elevator, its showing as -20% maybe try -15%?

This one is at my "local" hill in a strong breeze. The glider is a 2.3m K-8 but has rudder/elevator only so there is almost no way to bleed off air speed on approach... It too 3 go-arounds to get it on the deck... cross wind and sloping surface. In the end I came lower and lower with each pass and managed to not crash in the turbulence, not come in too hot and kinda had to stick down at the end as the hill started to drop away! NOT pretty but no damage... :)


https://youtu.be/T3VvDqQDYko

mjcp
 

JohnC

Member
I'm definitely going to wait for a calm day and work on my coordinated turns. I have accomplished turns where I sent the ailerons in one direction and the rudder in the other to slip sideways. I need to practice that.
 

Jowano

Junior Member
Great to see some fellow slopers in the forums. I fell in love with slope soaring after watching some warbirds soar with no electric assistance. I love my Dazi coroplast wing and make sure to use it first to test any new spots that I discover. I'm currently trying to slope the FT bushwacker. I maidened it yesterday but had the CG far to forward based. Luckly there were some soft bushes to land in so the damage was minimal.

Has anyone else had success with FT designs on the slope? I know the versa wing is a popular choice.
 

alpea 41

Member
I didnt read all your advice being an accomplished slope soarer ive hiked down and up to retrieve so many times i lost count. Then one day you learn where the best lift is and the hiking all becomes a distant memory. I do feel the best site is not a round hill top though. It is more a hill with a bowl or a canyon that funnels the wind into narrow gorge . This increases its speed and volume and makes the lift stronger.
 

alpea 41

Member
Im lucky my hill is 5 mi away. Im still waiting for spring conditions. But yesterday a buddy flew a thermaler in less that 5 mph wind the video is up at my thread sloaping sites in So Ca.
 

MotoPilot

Junior Member
When I lived in LA I used to love slope soaring on the cliffs overlooking the ocean.
I used a little balsa glider, and was also amazed at what the fiberglass planes that had a couple pounds of lead in the nose could do in a stiff breeze.

This was my favorite spot!
bluffcove.JPG
 

Foam Addict

Squirrel member
I didnt read all your advice being an accomplished slope soarer ive hiked down and up to retrieve so many times i lost count. Then one day you learn where the best lift is and the hiking all becomes a distant memory. I do feel the best site is not a round hill top though. It is more a hill with a bowl or a canyon that funnels the wind into narrow gorge . This increases its speed and volume and makes the lift stronger.

Lol, now I would definitely agree with you. It just so happens that that hill was all I had access to at the time. Now I can't fly near my school, so I'm still looking for a not to distant site to fly big gliders again. :)