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slope soaring

bracesport

Well-known member
@Piotrsko - you don't know how excited I have been waiting for your comments! :D

First of all, phew, first attempt over, and I lived to tell the tales - I have already stripped the red and yellow sailplane and will fit a new 3D printed fuse to the wing. It will be a V tail and (OK) I will ditch the spinning security blanket up front!

Secondly, the little red one did fly better as you say when out a bit further from the cliff - do you think the elevator setting (currently flat) needs a few clicks of down trim, or do you think I was subconsciously holding the stick down a bit willing it to go up - it seemed to fly well and fly bad, so do you think ballast under the CG would help with the speed, or is it just a trimming issue?

Thirdly, I was impressed that given the weight differences between the two ships that they both could fly well on the same day, so I am encouraged and excited to finish the Ridge Rat too!
 

Piotrsko

Well-known member
As you get closer to the hill the wind speeds up (Bernoulli effect) so it is difficult to "penetrate" that unless you can fly faster. You can try to hold down elevator, but sometimes it isn't enough or it's too much. You end up in a dive that even monster lift cant overcome so you do this porpoise up and down which is very tiring. Slowing down to climb ends up shoving you backwards. The "two clicks" down allows you to get away from the cliff face, gain speed, then add up to climb way higher into smoother slower air. There you can put the normal trim back in.

Judging by the video sound, you were flying in what I would think is about 30km wind, a bit much for the red plane as it flies right now, 10 less would be perfect, wouldn't need any downtrim. It also appears the wind was from the leftish because the bowl on the right didn't seem to be working.

You did get a lesson in wing loading versus speed and I see it is percolating through the thought processes. In a short while you should be a building flying monster. Maybe better than most, including me (not that hard), probably as good as hai-lee

All in all, a thoroughly profitable episode. Do it again. Bwaahaahaahaa, Igor, we've caught another one.

Finally: did you ENJOY it? Crash and annoying fetch? If yes, then you're hooked.
 

Piotrsko

Well-known member
Great job @bracesport. inspirational as always. I saw the loop too.
There is a glider-port up the road a while... I might head up to see what all the hub bub
That's thermal. Much different than slope, but more challenging in a different way and just as fun. I have a 50 hours in type

Get rid of that NOOB in your signature, you no longer qualify......
 

bracesport

Well-known member
Kind words @Piotrsko @FoamyDM - I think the slope thing will suit me better with 'wind' more than 'no wind', and both north-facing and south-facing slope sites near home - I still want to crack the powered thing at the park so as the weather and time allow I will do that too!

fleet under development
1- 1.5m sailplane (recently deceased) - upgrade path - bixler3 wing with flaps and crow - 'V' tail this time with rudder - 4D printed fuse.

2- 1.2m v1 'V' tail DLG (currently flyable) - needs a bit of tuning after the recent flight.

3- 1.3m v2 DLG (newsprint wing) over on the other thread is coming along and it is currently getting a 'T' tail so I can have a go at discus launch - the reason I mention it is that if I slope with it, the tail will be fragile on landing so I am contemplating two tails one 'T' and one 'V' - or maybe I am overthinking it (it is my homage to @flyboa and his excellence with FB DLG's)!

3- flat nose Versa - set up as a pusher (ready for maiden) - lots of talk about how well these can slope - plan to park launch it and get it dialled in, then maybe it is also a slope contender!

4- FT Spitfire - (ready for maiden) - again, I will park launch it to complete the group build and maiden journey (this one is heavily modified with 3D printed parts and decorations) - also have a backup build strictly FT style).

5- 1.3m Ridge Rat - quite a lot of work yet to finish this one - wings are ready for covering - fuse is being filled and sanded - tail feathers ready for fitting to fuse - loving this project with its 'tech' components and assemblies (it is my homage to @thenated0g and all the wonderful slopers he builds)!

6- spare 1.5m DLD wing - was too heavy on a recent build - needs a new home!
 

Piotrsko

Well-known member
"T" tails are a personal favorite and preferred system, v tails on one servo is just flat annoying for linkage. Used both never had a fragile issue. Remember my old servos weigh as much as one of your wing halves.

Use the Spit for cool motor flying with flatlanders. I am just not feeling that as a successful glider.

As Hai-lee says " Have fun"
don't for get to commit heinous acts of unrepentant aviation as often as possible
 

bracesport

Well-known member
@Piotrsko - yes, the V tail connections as a single elevator (and even as a full tail setup) is complex by comparison - my new DLG without 'T' tail fitted, Rx, servos, and battery are 180g, so this puppy is not going to be heavy at all!

hehe - you are probably right on the Spit - plenty of other options for the slope! :D
 

mayan

Well-known member
@bracesport thank you for the amazing videos. I actually felt like I was there with you, stressing with you when you were getting ready to do the hardest thing, throw a beautiful looking plane off a cliff. You could see in the videos that the next time was easier for you and the one after that even easier. I am proud that you finally did it, and thank @buzzbomb for kicking your ass to do it, great job both of you. Can't wait to see more videos of you slope soaring. Winter is arriving here and I think this will be about time to go sloping in my part of the woods, as the wind is starting to be stronger, I'll try looking for a good sloping site.

Oh by the way, you need a higher steeper cliff. More incentives. This is a SOARING site
That's either make it back to the top or say good bye to your plane. I remember when I used to live in Portugal that they had sites like that.
 

Piotrsko

Well-known member
member: 40146 said:
That's either make it back to the top or say good bye to your plane. I remember when I used to live in Portugal that they had sites like that.
Cliffs of Moher, Ireland. 100 to 200 meters tall, 40 km wind all going UP. My wife who has no interest in my flying whatsoever said exactly the same thing. However, the site was such that if the plane exploded, all the parts would end up a couple of miles on top behind the cliff. I am not sure it is even flyable in something less than a actual 747.

@mayan : you need a hill /ridge about 30 meters long, at least 10 meters high with nothing in front for a while. I have sloped sand dunes, and with permission for roof access, 6 story apartment buildings. Any of your current planes will slope and using a motor with prop plane to bailout is very helpful at a new to you site. Since you can immediately refly after landing, you'll be just fine.
 
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mayan

Well-known member
Cliffs of Moher, Ireland. 100 to 200 meters tall, 40 km wind all going UP. My wife who has no interest in my flying whatsoever said exactly the same thing. However, the site was such that if the plane exploded, all the parts would end up a couple of miles on top behind the cliff. I am not sure it is even flyable in something less than a actual 747.

@mayan : you need a hill /ridge about 30 meters long, at least 10 meters high with nothing in front for a while. I have sloped sand dunes, and with permission for roof access, 6 story apartment buildings. Any of your current planes will slope and using a motor with prop plane to bailout is very helpful at a new to you site. Since you can immediately refly after landing, you'll be just fine.
I'll give it a try soon, when the winds only allow for slope soaring.
 

bracesport

Well-known member
@mayan - my sim time is limited to the trackpad on my mac (no sticks)! :D

I posted my maiden on RC groups and got some more tips to share here - the landing tips assume landing up where we started (not down at the beach)!

Setup

As a beginner you ideally want the glider to have the CG a little bit forward. This will make it be more stable, meaning it will want to pull up from a dive by itself, even while the elevator is centred, neutral, level and even with the horizontal stabiliser, but it shouldn't be pulling up when it's going kind of slow like in straight and level flight, only when you put it in a dive, say 45 degrees down angle. Later when you become better, you can move the CG back to neutral where it says it should be, or even a little behind it when you become even better.

Check for any slop in your pushrods, or linkages, with no binding, or double neutrals and check everything is centred.

The V-tail has no angle of attack, it is lined up even with the bottom of the wing. But the bottom surface of the wing isn't what matters, it's the wings' chord line (centre of the LE to the centre of the TE) is the line that should be parallel to the stabiliser. This means there is some 'built-in' up elevator, so long as it's not too much we can live with it.

1- Feed in a few beeps of down trim, go to a park, run with it holding it level, and just slightly let go, then grab it again. Adjust as necessary until it stays pretty level when you run and release it, then recapture it.

2- Hold the fuse just behind the CG, take one step, and firmly but not hard, toss it aiming at a spot about 20-30m in front of you.

It shouldn't climb or dive. It should fly pretty level, maybe slightly nose down, performing a nice descending glide, almost hands-off, and should almost be able to land by itself.

3- Try again, but this time 'flare' a little before touch down to make the landing more gentle.

4- Now you can hold it behind you, the palm of your hand facing up, take a few steps and throw it harder and up, like a grenade launch. Before it slows down and stalls, push the nose over and level out. Now you're higher and you can do a gentle turn making a big circle.
and land.

After you trim it to do good test flights in the park, look at the elevator (actually, since you have a V-tail, they are called ruddervators). Does it look like you have up trim, down trim, or are the ruddervators level with the V-tail? This should give you an indication if your CG is correct.

Good test flights with the ruddervators level with the V-tail indicates a correct CG (assuming the angle the V-tail is mounted at in relation to the wings’ chord line is correct). Good test flights that have up trim indicate a CG that is too forward. Good test flights that have down trim indicate a CG that is too aft. So long as the CG is close, the ruddervators should be close to neutral.

Slope

Back at the slope, the wind speed should be at least as good as the maiden, and close to perpendicular (straight in) to the slope.

1- Now to test the CG at the slope again, and perform a dive test. Once you get pretty high, point it into the wind, quickly push the nose down to a 45-degree angle down, and let go to see what happens. It should slowly, gently, pull up by itself.

If it pulls up kind of hard, you probably have too much up trim, needed to fly level when it’s flying slowly, but kicks in at a faster speed. This indicates a CG that is too forward, and the up elevator trim is needed to keep the nose from dropping when flying level and slowly.

If when you dive, if it starts to dive steeper, then you probably have too much down elevator trim, needed to fly level when flying slowly, and when it starts going faster, that down elevator trim kicks in, making it dive more. (NOTE: If it does this, and starts diving steeper, tucking under, quickly but gently pull back on the stick so it doesn't get going too fast. Don’t pull back too hard, you don’t want to fold the wings, but you don’t want to let it get going too fast either.) Having too much down elevator trim is usually because of an aft CG, and the down trim is needed to fly it level when it is flying slowly.

2- You shouldn't have to throw your glider hard or up (that can start the porpoising). Nose slightly down, gentle launch. In a good lift, the nose can be slightly down, but the glider will still climb.

3- Remember, it's not a power plane. If you pull back on the stick expect it to stall. Fly it higher. If you fly it below the slope edge you are losing out on lift. If you get 1/3 or 1/2 down, you might have a hard time getting it back up. Try and fly back and forth, from left to right and right to left, making your gentle turns away from the slope, with a little bit up elevator during your turn, trying to stay just a little bit out in front of the edge.

4- Try to make gentle turns, always turning AWAY from the slope, like a figure 8. Use just enough back pressure on the stick
(up elevator) in your turns to keep the nose about level. At first, you don't want to nose to dive in a turn, or to climb in a turn.

Keep in mind that the more you bank the glider, the harder you will have to pull up elevator to keep it from diving down. Later as you get better and very comfortable with what you are doing, you can do steeper turns, pulling back harder on the up elevator. But remember, with steeper turns, you should going a little bit faster, or else if you are slow, bank hard, pull up hard, you can stall. Later you can also do loops, stall turns, and maybe even a roll if you have enough rudder authority.

Landing

Try to land up top, not on the beach. It’s too hard at this stage for you to be able to tell well what it’s doing and how to control it well from so far away, and from that vantage point.

The first thing you want to do when you decide you want to land is to feed in some down elevator trim, say about 4 clicks (or beeps). You might only need as little as 3, or you might need as many as 6. But start off with 4 clicks (or beeps) at first.

You don't want the glider to start diving and continue diving more and more or going really fast. But you do want the nose to be pointed just a little down so the glider isn't gaining (much) altitude any longer, and so it's going a little bit faster vs when you were out in lift trying to gain altitude.

1- To do a slope landing, you need to feed in some down trim, and go out away from the slope, out of the lift zone, do big gentle circles, descending, to at or a little below ½ way down the slope, then come downwind at a 45 degree angle to the slope.

2- As it comes closer, it’ll start rising. Try to time it so that when you get to the edge of the slope, it is just a little above the edge of the slope, then I turn around into the wind and lightly dive it into a bush.

If you don’t make it up to the edge, just turn back into the wind a little early and go out and try it again. If you end up too high, do the same thing again.

2- Try to be at least 50' above you when you start your downwind leg of your approach. KEEP IN MIND airspeed vs ground speed.

If your glider is pointed into the wind, and the wind is 10mph, you can be barely moving forward and that's still plenty of wind moving over the wing to keep it from stalling. But if you are pointing WITH THE WIND (downwind) and are only going the same speed or even slightly more than the wind, then that is not enough wind moving over the wing to prevent a stall.

3- Instead you have to be moving at least 15mph downwind (in the given example above, when the wind is 10mph).

Also, don't bank your wings hard. The worse thing you can do on a landing is to be going downwind, not moving very fast, and bank the wings hard. That's a recipe for a downwind tip stall. Downwind (tip) stalls are difficult to recover from. You better hope you are pretty high if that happens.

4- Pick a spot near your landing area, which should be back and out of the lift zone, and do gentle circles losing altitude. Try to time where your circles are in relation to your landing spot, with the width your circles, and your rate of descent, so that when you get down to about 10-15 feet above the ground, you can straighten out for your final approach. You should now be able to point glider at your landing spot, be still descending, while not going to very fast.

5- When you are about a foot or two above the ground, pull up SLIGHTLY to slow the descent. Keep it moving so it doesn't stall. And when it's just about to touch the ground, pull up just a little more to FLARE for the landing.
 
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thenated0g

Drinker of coffee, Maker of things
Mentor
Nice thing about slope soarers is that "usually" you are landing because of a reason other than your out of battery and NEED to land before the power is gone. Meaning that you can slowly get closer and closer to your landing area, coming in from different directions and testing how your going to slow down and land. Fortunately when i got to my first slope landing i had already had a lot of powered flying under my belt. Tick point where i usually fly is not an easy place to land especially as all of my planes lack flaps and breaks. Most of the landings at tick require you to finally just push the nose down into the ground so it doesnt go off the side of the hill.

After getting comfortable, turning INTO the hill is a lot of fun :)
 

Piotrsko

Well-known member
@thenated0g : have you ever tried starting your landing from about 2/3 of the way up and forcing the hill slope to slow you while going up as you come up the hill in a sort of slideslip? At Bluff cove we had to go all the way down to the beach to get slow enough coming back up. Ideally, you stall where your landing point is. Your slope is also a perfect place for crosswind catching, where you turn hard just as you get into reach (its a timing thing) but not the fast stuff or the long wing stuff.
 
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thenated0g

Drinker of coffee, Maker of things
Mentor
@thenated0g - I think I did not focus enough on staying up high, and possibly the CG needs to move forward a tad! :D

(let's face it, it was the first time out, so I was thankful for any form of success)!
yeah, i tried over and over again for 2 years, every family trip, driving to places, etc before i finally got a successful flight. Soooo many walks down a hill to get my plane lol. But it was worth it, totally addicted now.
 

bracesport

Well-known member
I starting reviewing the V tail DLG and first reattached the wing that de glued with the first landing (taped on for the rest of the flights).

Once done I reset the throws and centres and lowered the rate on the elevator and added some expo - I think I was over doing the elevator while flying.

I checked the CG again and I think my original CG position was incorrect, so I remarked the CG points at 30% of the wing and with the current nose weight it was tail heavy - this required a bit more nose weight (but no room inside). I used a nail taped to the nose and now we have a slightly forward CG (nose down).

I am hoping this will test fly a bit better! 😀

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