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vortexr1

Leaning back while coming in fast

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I thought leaning back while coming in fast was done just because chicks dig it and it looks cool on camera.

With all my many jumps I know I am still just an okay canopy pilot and I am impressed with what these guys can do with a parachute. On the other hand I know a little about physics and I can't imagine leaning back in a harness with two attachment points has any effect whatsoever.

I've been wrong before though. It was in summer of 1979 if I recall correctly.:)
"For you see, an airplane is an airplane. A landing area is a landing area. But a dropzone... a dropzone is the people."

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Hi Morris I only have just over 400 jumps and have completed a inter swoop course by aussie champ Matt Harris. Are you saying that while I pitch the canopy forward and start my roll all the way through the yaw and roll out that I should have my weight back to get my canopy to dive steeper? Any help will be greatly appriciated. Cheers Shakey[email] daleskydive@yahoo.com.au

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HI Morris,I only have just over400 jumps and

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I have just completed an intermediate canopy swoop course with Matt Harris. I want to make sure I have this right. So when I pitch roll and yaw its best to have my weight back a bit more to the rear of the canopy even when Im rolling out of the dive. Correct? And while I have plenty of airspeed move my weight forward until my airspeed starts to diminish? And when my airspeed diminishes?

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Awesome post(s)

Was very interesting to see so many people doing this in Dubai with some very different results. It does seem that people can kill their power with a poorly/late executed version of this maneuver

I used to do it (poorly) and after awhile a coach mentioned that I would probably be better off without it (which has also been true!)

One of my team mates does it very well, very smooth and very early on. For him it works very well as he seems to carry his power very well from a 270. I am always amazed and what he gets from it with some turns as some of them do not seem to be very powerful (or might be a bit sloppy). His transition in and out of the body position is very good, very smooth and you can see that while watching the canopy during his transition.

In terms of doing it like a paraglider - Scott Roberts has a set of gear setup like this. Was amazing to see him fly it around, the drag reduction appeared to be very noticeable (in full flight with the same canopy/same loading). So it will be interesting to see if anyone gets around to doing this for comp.
"Don't blame malice for what stupidity can explain."

"In our sleep, pain that cannot forget falls drop by drop upon the heart and in our despair, against our will comes wisdom" - Aeschylus

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Do you not just pivot around the 3-ring?



You do. From a fore/aft perspective, you're just a side of beef hanging from a meat hook. If you hook a side of beef in the center, it hangs level from the hook. If you hook it to one side, the 'bigger' end on one side of the hook will droop, while the 'little' end will raise. If you look at it from the side, and imagine a plumb line exending down from the hook, you'll see equal mass on either side of the line.

Same thing under canopy. You're always going to hang straight down under the canopy/3-ring, it's just how it works. Even if you could find some way to sustain an off-center position, the confluence wrap on the bottom of the riser will cancel out any forces you might be imparting. The risers don't become 'front' and 'rear' until above the confluence wrap, so any input intended to be specific to one riser or the other needs to be made above the confluence wrap. As it sits, the confluence wrap is above the pivot of the 3-ring, so you those two factors inbetween you as a hanging mass, and any discreet input to the front or rear risers.

The benefit to the forward lean is aerodynamic. It's very slight, and reduces exponentally with the decrease in speed, but that's the benefit. More important than that is flying a clean approach, and maintaining correct control inputs during the swoop. I would venture to say that spending time learning to lay forward in the harness without perfecting the rest is probably a waste. Chances are that you're going to give up some distance jacking around your body position, so you're giving up one thing to gain another.

Truth is, I wonder if laying back like a PG is the better way to go. As it sits, at the end of a distance run the pilot makes a huge move in the harness to pivot back and land on their ass. Some might argue that the swining motion might create a temporary pitch-up, but I would suggest that by the time the pilots are making that move, the canopies have 'given up the ghost' and are not going to be going any further. So if pilots could adopt a laying back position, they could remain still in the harness and maintain that position all the way to touchdown.

That's limited to competition distance runs. For normal swooping, you do want to be leaning forward to get your weight out in front of your feet, and facilitate running out a landing.



I would like to point out/make the argument that when most pilots are leaning forward in their harness, they are not actually suspended from the single attachment point alone (3-ring) but are usually using the rears and/or toggles as a canopy input as well as a point of leverage to move their weight forward and drive the flatter glide/lift which has been explained higher in the thread by a parabolic weight shift. Basically, the pivot point of their riser input acts as a temporary pivot point, even if minimal; similar to a swingset. If I understand your explanation correctly, your argument would result in a child just sitting in the swing kicking their legs back and forth, instead of using their hands on the chains to create those temporary pivot points that lead to weight shifts, and in turn, swinging.

I too have experimented with this heavily in countless hours of groundlaunching and have come to this conclusion myself... I am not arguing against the aerodynamic benefits (which are undeniable) but I think the benefit to the wing and glide are being understated. The place of confirmation for me was not in examining HP approaches and landings, but very very slow soaring in close proximity to the ground. Yes, the weight does eventually center itself, but until it does so the benefits are clear. When soaring a 135 Stiletto, I'm sure the aerodynamic benefits are not as exaggerated as weight shifts, which make a very immediate and clear benefit to the glide path of the canopy. If I go from a fully leaned-out posture soaring 5 feet above the ground and then sit back in the canopy, I find myself sitting in the sand immediately.

I don't have much competition experience, but I'm fairly certain that the primary reason for pilots to sit back on distance runs is because face-first landings hurt and they can extend their legs for that extra stretch, not unlike a long-jumper... not because of any last minute pitch-up.

I'd like to come to a scientific conclusion on this if we could... I've heard this debate many times now, and usually results in an "explain why it works" versus "it just does." Those who have experienced the benefits recognize it, and those who haven't just aren't there yet.
It's all fun and until someone loses an eye... then it's just a game to find the eye

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they are not actually suspended from the single attachment point alone (3-ring) but are usually using the rears and/or toggles as a canopy input as well as a point of leverage to move their weight forward and drive the flatter glide/lift which has been explained higher in the thread by a parabolic weight shift.



Technuically, you could look at any riser/toggle input as a type of weight-shift device, as applying one will change the drag profile of the wing, and allow the pilots weight to shift underneath and enact further change.

At the end of the day, however, it is not a 'true' weight-shift craft, as there's no way to sustain that input for very long. In a true weight-shift craft (like a hang glider), the control bar is a solid point of attachment that allows you direct control over your position under the wing, as opposed to a canopy where all you can do is indirectly influence the wing to allow your weight to shift.

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When soaring a 135 Stiletto, I'm sure the aerodynamic benefits are not as exaggerated as weight shifts, which make a very immediate and clear benefit to the glide path of the canopy. If I go from a fully leaned-out posture soaring 5 feet above the ground and then sit back in the canopy, I find myself sitting in the sand immediately.



Are you flying with no input before you change your position in the harness? It's been said many times that it might 'feel' like a change in fore/aft postion has enacted change, but what it really does is change the angle/position from which you apply toggle/riser input, and you end up alter that input inadvertanly during the change in position.

What you would really need to test this is either some way to measure it during full flight, where the shift in position is the sole input being given to the canopy, or some sort of riser or control lock, which you could 'set', and in turn make sure that your position shift is the only chnage to the canopy.

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but I'm fairly certain that the primary reason for pilots to sit back on distance runs is because face-first landings hurt and they can extend their legs for that extra stretch



I'm sure both of those are true as well, which is why I suggested that there might be a way to fly the entire run leaning back instead of forward. You could realize the same drag reduction provided you could assume the same angle of lean, and you would avoid the big transition move at the end of the swoop. It's been said many times that the less you move in the harness the better, so why wouldn't that apply to the end of a distance run?

There are obvious problems in reality with the idea, such as the main/reserve container being in your way preventing you from leaning all the back, it's just more of a 'theoretical' or 'what if' sort of idea.

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One additional thought, canopies aren't traditional 'weight-shift' craft, but they are close. Maybe the term 'weight-swing' is a better way to describe the control method of a canopy?

The primary difference being on a weight-shift craft you can apply and hold input, while on a canopy (weight-swing) your degree of input is limited to the pilot's swing under the wiing. While you can hold an input on a canopy for as long as you like, the pilot's tendency to swing back under the wing will cancel out of most of it when that swing is completed.

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they are not actually suspended from the single attachment point alone (3-ring) but are usually using the rears and/or toggles as a canopy input as well as a point of leverage to move their weight forward and drive the flatter glide/lift which has been explained higher in the thread by a parabolic weight shift.



Technuically, you could look at any riser/toggle input as a type of weight-shift device, as applying one will change the drag profile of the wing, and allow the pilots weight to shift underneath and enact further change.

At the end of the day, however, it is not a 'true' weight-shift craft, as there's no way to sustain that input for very long. In a true weight-shift craft (like a hang glider), the control bar is a solid point of attachment that allows you direct control over your position under the wing, as opposed to a canopy where all you can do is indirectly influence the wing to allow your weight to shift.

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When soaring a 135 Stiletto, I'm sure the aerodynamic benefits are not as exaggerated as weight shifts, which make a very immediate and clear benefit to the glide path of the canopy. If I go from a fully leaned-out posture soaring 5 feet above the ground and then sit back in the canopy, I find myself sitting in the sand immediately.



Are you flying with no input before you change your position in the harness? It's been said many times that it might 'feel' like a change in fore/aft postion has enacted change, but what it really does is change the angle/position from which you apply toggle/riser input, and you end up alter that input inadvertanly during the change in position.

What you would really need to test this is either some way to measure it during full , where the shift in position is the sole input being given to the canopy, or some sort of riser or control lock, which you could 'set', and in turn make sure that your position shift is the only chnage to the canopy.

Quote

but I'm fairly certain that the primary reason for pilots to sit back on distance runs is because face-first landings hurt and they can extend their legs for that extra stretch



I'm sure both of those are true as well, which is why I suggested that there might be a way to fly the entire run leaning back instead of forward. You could realize the same drag reduction provided you could assume the same angle of lean, and you would avoid the big transition move at the end of the swoop. It's been said many times that the less you move in the harness the better, so why wouldn't that apply to the end of a distance run?

There are obvious problems in reality with the idea, such as the main/reserve container being in your way preventing you from leaning all the back, it's just more of a 'theoretical' or 'what if' sort of idea.



As far as soaring the Stiletto, my observations mainly refer to launches; running to the edge on or hitting the rears doesn't produce nearly the lift (even if just instantaneously) of leaning nearly out of the harness (usually no chest strap in the foam pit) with the same riser input.

The hang glider example makes perfect sense to point to what is basically a compromise of our "craft." Just as these guys are cranking down their risers for XRW, perhaps some sort of locking device (AKA 'control bar') could be implemented here as a test device-- once the risers have been 'set' on plane-out, the pilot just sits still in the harness waiting for the transition to toggles?

I think the ultimate point here is there is definitely a benefit to weight shifts (forward/back) in the harness, and we are ultimately just looking for the perfect timing and balance of all these inputs.

**Realizing cranking down the risers is less of a permanent 'swing' input and more of a permanent control input, that experiment probably wouldn't prove a damn thing... but I'd still just like to -know-
It's all fun and until someone loses an eye... then it's just a game to find the eye

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