Leaning forward while swooping..

[perse 0]

...What's the physical reason all the CP professionals lean forward in their harness when flying level at he end of their swoop? How does it make the canopy fly better? Why is it better than just staying in the middle of the harness? Or does it just look cool

[twnsnd 1]

It actually makes the canopy pitch slightly upward, which assists in the flare process while causing very little drag. It also just feels natural to do it.

-We are the Swoophaters. We have travelled back in time to hate on your swoops.-

[AndyMan 7]

Good question. I was wondering the same thing.

I was playing under canopy last weekend and couldn't notice any difference in canopy performance. My Samurai seemed to dive at the same rate, with the same riser pressure, and recover at the same rate when I was leaning forward or not. I always had trouble with the theory that it would affect your canopy performance since the 3 rings act as a pivot point in the system. My observations last weekend support my opinion that there is no effect of leaning forward.

To me, the big part of leaning forward is during the plane out. Leaning forward will "shorten" your arms when it comes to hitting the rear-risers, meaning you're closer to your "power band" in your arm muscles. . It'll also help keep your feet directly under your center of mass when you start to put your feet down to slide.

Your milleage may vary, of course.

_Am

__

You put the fun in "funnel" - craichead.

[ryoder 1,410]

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It actually makes the canopy pitch slightly upward, which assists in the flare process while causing very little drag.

How? You are attached to the canopy at two points: Your left and right three rings. In order to change the fore-aft weight distribution of the canopy, you would need to be able to shift weight between fore and aft located attachment points.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[superstu 0]

Alright, this will be a little tough to explain online but i'll try and put in my .02

think of it this way, you are a pedullum(sp) under your canopy. when you do a regular flare or when other people come straight in and flare, which way does their body swing compared to the canopy? you swing forward right? so your body is now more toward the front of the canopy and your canopy has a higher angle of attack (AoA), which means you have lift (unless you have too high of an AoA then you've reached your stall point.) so weight forward= >AoA= lift.

now in swooping we are trying to be as most efficent as possible. if you can change where you are under the canopy while keeping the canopy as true to form as possible (ie not deforming it with risers or togles) then that should be the most effecient way to fly across the ground. so when you're trying to eek out that last little bit of flare, CP's are leaning forward so they have to use less of their inputs so they distort their canopy less which means they can go just a little bit further because they were just a little more efficient. however, it's such a fine line that for a lot of people they either don't see the difference or feel the difference because they just don't have the experience yet.

hopefully this kinda made sense.

Slip Stream Air Sports
Do not go softly, do not go quietly, never back down

[superstu 0]

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My observations last weekend support my opinion that there is no effect of leaning forward.

if there is no effect then why would pro's, who are paid to do well in competitions and push the limits, do this?

it has to do with your center of gravity under the parachute.

Slip Stream Air Sports
Do not go softly, do not go quietly, never back down

[Tonto 1]

I don't know, but I've always done it. (About 18 years now... long before "swoop" competition."

For me it has always been about visibility during the turn, as with a "Normal" position, you have risers at 90 deg, so leaning forward does alter that. Also, from a parasite drag point of view, leaning forward, and tucking up or extending a leg forward presents much lower drag.

There are also benefits to impact absorbtion in the event of error, but I don't think most people think that far.

It feels like the right thing to do.

t

It's the year of the Pig.

[twnsnd 1]

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How?

It's difficult to explain, but I'll try. Superstu's post below is accurate. You are attached to the parachute at two points, but because we are talking about movement from front to rear and not side to side, you are effectively talking about one singe attachment point. If you think about this one point as the pivot point between two forces, then you can start to see how when you lean forward, the canopy will pitch backwards, or up. If you lean backwards, the canopy will pitch forward, or down. Hope this helped.

-We are the Swoophaters. We have travelled back in time to hate on your swoops.-

[ryoder 1,410]

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How?

It's difficult to explain, but I'll try. Superstu's post below is accurate. You are attached to the parachute at two points, but because we are talking about movement from front to rear and not side to side, you are effectively talking about one single attachment point.

I agree with everything through this point.

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If you think about this one point as the pivot point between two forces, then you can start to see how when you lean forward, the canopy will pitch backwards, or up. If you lean backwards, the canopy will pitch forward, or down. Hope this helped.

If I believe this last section, then I must also believe that if I attach a pair of risers to the ceiling and to my harness, then just by leaning forward or backward in my harness, I can make the risers change their angle with respect to vertical, rather than just hang vertically.

You still need load points separated front-to-back. Now if the pilot is applying some of his weight to risers, that would effectively produce four points of attachment, and would enable shifting weight fore and aft on the canopy.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[twnsnd 1]

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If I believe this last section, then I must also believe that if I attach a pair of risers to the ceiling and to my harness, then just by leaning forward or backward in my harness, I can make the risers change their angle with respect to vertical, rather than just hang vertically.

You still need load points separated front-to-back. Now if the pilot is applying some of his weight to risers, that would effectively produce four points of attachment, and would enable shifting weight fore and aft on the canopy.

Well, you're obviously not going to move the ceiling unless your weight is greater than the bursting strenghth of the walls. And if you could, you would not be changing the position of the risers at all, you would be moving the entire system as one piece from the three rings up. Just think about the pivot point analogy. If you move a direction on one side of the pivot point with enough force, then whatever is on the opposite side MUST move in the opposite direction. Getting any clearer.

-We are the Swoophaters. We have travelled back in time to hate on your swoops.-

[ryoder 1,410]

You can't shift your weight distribution on a canopy by leaning forward or backward because you are hanging from a freely pivoting load point with no way to apply leverage forward or backward, unless you use risers or steering lines.

Now let's pause from the fixation on shifting weight for a moment:

Look at a swooper leaning forward in the harness;
- Torso tilted forward with respect to the relative wind, instead of upright.
- Legs swept back with knees partially bent.
- Arms swept back.

What to all these things have in common? They are reducing aerodynamic drag. All of the lab papers on ram-air canopy research establish that reducing the drag on the payload of a ram-air canopy flattens the glide angle. And the higher the speed, the more pronounced the effect will be.

I'm not saying that leaning forward doesn't work; I'm saying that there is a misconception on why it works.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[perse 0]

Actually you have to think it that way that you have four points of attachment since you usually have your rear risers pulled a little bit apart or down when you´re leaning forward. or toggles.

How do they do this "Ghostrider" landing?? Have you seen anyone doing that leaning forward??

[twnsnd 1]

Yeah, but we were'nt really discussing that aspect of it.

-We are the Swoophaters. We have travelled back in time to hate on your swoops.-

[twnsnd 1]

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I'm saying that there is a misconception on why it works.

This is entirely possible. You have your body weight on one side of the pivot, and the drag and lift of the canopy on the other side. The only thing I will add is that when I flare hard, my body swings forward, and when I pull both front risers, my body swings backs...and there is still a freely floating pivot point with apparently no way to apply leverage.
Hmmmm...

-We are the Swoophaters. We have travelled back in time to hate on your swoops.-

[ryoder 1,410]

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I'm saying that there is a misconception on why it works.

This is entirely possible. You have your body weight on one side of the pivot, and the drag and lift of the canopy on the other side. The only thing I will add is that when I flare hard, my body swings forward, and when I pull both front risers, my body swings backs...and there is still a freely floating pivot point with apparently no way to apply leverage.
Hmmmm...

Both of your examples are the result of inertia:

Flare: Canopy abruptly slows. Payload tries to continue at same speed, so it temporarily swings forward, until it's speed matches canopy.

Front riser: Canopy abruptly increases speed. Payload tries to continue at same speed, so it temporarily lags behind canopy until it's speed matches canopy.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[twnsnd 1]

Is there any way that inertia is playing into the harness lean?

-We are the Swoophaters. We have travelled back in time to hate on your swoops.-

[ryoder 1,410]

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Is there any way that inertia is playing into the harness lean?

The payload has a mass many times that of the canopy, but the canopy has many times the surface are of the payload, so it is the canopy that is always applying aerodynamically generated lift and turning forces to the payload. I can't think of a way the payload could apply such a force back to the canopy, unless the payload had an engine.

But as Dennis Miller says: "...then again, I could be wrong."

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[twnsnd 1]

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unless the payload had an engine.

But we are the engine right? The canopy cannot create lift without the weigh suspended beneath it. If we had a propeller on our backs like powered paragliders, wouldn't the canopy initially rock backwards when more thrust is applied. Since the weight is trying to accellerate, there is a lag while the canopy tries to catch up resulting in the momentary upward shift.

-We are the Swoophaters. We have travelled back in time to hate on your swoops.-

[marks 0]

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...What's the physical reason all the CP professionals lean forward in their harness when flying level at he end of their swoop? How does it make the canopy fly better? Why is it better than just staying in the middle of the harness? Or does it just look cool

because, your head is farther forward, so it seems like you go farther.

[CanuckInUSA 0]

You and Yoder are hurting my brain with all your back and forth talk (but I am experimenting more with that harness turn technique you told me about just before I left CO and I like it).

Try not to worry about the things you have no control over

[AggieDave 6]

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How does it make the canopy fly better? Why is it better than just staying in the middle of the harness?

It feels good and its styley.

I'm not fully convinced that it actually does anything but set yourself up to drag a toe in water a little easier.

With that said, I find myself leaning foward most of the time while swooping, I don't even mean to do it, it just happens...pushing hard against my loosened chest strap.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[ryoder 1,410]

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unless the payload had an engine.

But we are the engine right? The canopy cannot create lift without the weigh suspended beneath it. If we had a propeller on our backs like powered paragliders, wouldn't the canopy initially rock backwards when more thrust is applied. Since the weight is trying to accellerate, there is a lag while the canopy tries to catch up resulting in the momentary upward shift.

I expect if the engine can accelerate rapidly enough, there could be an inertial effect, but what you are talking about also has a steady-state effect:

Changing the throttle on a powered parachute actually moves the point at which the payload hangs below the canopy. i.e. look at a powered parachute from the side, and draw a vertical line through the riser attachment point on up through the canopy. As the throttle setting is increased, the point at which the line passes through the canopy moves forward. Since the line trim of the canopy has not changed, this also puts the canopy in more of a nose-up attitude.

A powered parachute has one speed it likes to fly. The throttle controls the glide angle. Less throttle: steeper glide. More throttle: flatter glide. Even more throttle: level flight. Full throttle: climb.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[ryoder 1,410]

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You and Yoder are hurting my brain with all your back and forth talk (but I am experimenting more with that harness turn technique you told me about just before I left CO and I like it).

Yes, my head was starting to hurt, too. But after a glass of Shiraz, it is feeling much better now. Funny thing is that I didn't even realize who twnsnd was, until your post.

"There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones.

[davelepka 4]

Hasn't this question come up before?

Anyway, I think there are two parts to this answer.

First off, people lean forward in their harness during their turn because thats the direction they're flying, and it just makes sense. Any input to the harness you want to be of the forward/downward direction, so you can go faster,

Coming out of a turn, pressing into the harness will help to pitch the canopy up, and provide some lift (aka distance) without any riser/toggel input.

Once you are out of a turn, pushing forward will not produce any additional lift. You reach a point in your swoop where the pedulum effect of the turn on the pilot ceases, and this is th epoint where you need to pull on your straps or strings to make your canopy go further. At this point the poster who claims that only one connection point (in a front to back sense) makes pushing forward a fruitless persuit, would be correct.

However, at this point, leaning forward takes on another purpose, (which was also mentioned) which is just weight distribution for using your flintstone brakes to help slow your canopy down. You need to have your feet out in front of you, so you can apply rearward pressure to slow down. You also want your upper body forward and over your feet, so you don;t get caught leaning way back and get too slow to pick you upright.

The reason that guys do this during distance runs, or any time they're not sliding in ontheir feet is becasue they're used to it.

You have to remember that a landign is a complex event, and it invloves two forms of canopy flight. The first, during the turn, is where the pilots momentum under the canopy is creating the change in the system. The parachute and pilt are out of balance during this time, and the canopy diving is it's
attempt to regain the balance. This is the time where harness position will make a difference.

Once you are you of the turn, during the swoop, the system has largely regained it's balance. The pilots position under the canopy is relatively stable. The changes needed are slight, and enacted with risers or toggles. During this time, harenss position isn't important.

There are two answers to the question, beacsue there are two distinct flight modes present during a swoop landing.

[timmyfitz 0]

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...What's the physical reason all the CP professionals lean forward in their harness when flying level at he end of their swoop? How does it make the canopy fly better? Why is it better than just staying in the middle of the harness? Or does it just look cool

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I just took the advanced canopy course a few weeks ago with Scott Miller and Jonathan Tagle and this question came up. The answer was that it just feels better/more comfortable and kinda looks cool but doesn't add any discernable effect to the swoop.