Flight Controls

[NewClearSports 0]

After reading the Camber thread, it got me thinking about our wings and how different (more complicated) they are from rigid wings. It is quite amazing in how many different ways we can manipulate our parachutes. I can think of at least 8 controls every parachute has as well combined with the pendulum motion of being hung beneath the wing we also have a large variable wing loading.

Shall we brainstorm about our flight controls and there effects?
We all know what happens when you pull a toggle or a riser, but what would happen if you pull your right front riser and left toggle at the same time? I don't know, do you? What do you think will happen?

Cheers
Mike

[NewClearSports 0]

To get things started. Flight controls that I know of.

L-Toggle, R-Toggle
L-Front Riser, R-Front Riser
L-Rear Riser, R-Rear Riser
L-Harness, R-Harness

Also various combinations of the above
Flare & Brake L & R Toggle
Dive L & R Front Riser
Lift (Relative to normal flight) L & R Rear Riser

Also have you ever thought about how much our wing loading changes with various manuvers? Pull a high G turn = Increased wing loading. Pull a 2 G turn and my 2:1 wl goes to 4:1 !!!

[CanuckInUSA 0]

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but what would happen if you pull your right front riser and left toggle at the same time? I don't know, do you?

I've done it many times and it was taught to myself by a CReW dawg many many moons ago. It creates a lot of drag and is a way for a fast wing to fly with a slower one.

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

[CanuckInUSA 0]

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Also have you ever thought about how much our wing loading changes with various manuvers?

Any wing can stall at any airspeed and at any attitude.

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

[faulknerwn 36]

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We all know what happens when you pull a toggle or a riser, but what would happen if you pull your right front riser and left toggle at the same time? I don't know, do you? What do you think will happen?

CRWdogs use that trick all the time. Its called warping the canopy, and severely degrades the performance. Very useful trick for when you need to make your canopy slow and sinky!

W

[phoenixlpr 0]

Is that a similar trick to use one front riser and the opposite rear riser?

[conor 0]

A more general flight control that is often overlooked is BODY POSITION.

Most people just hang under their canopies like a sack of potatoes.

By getting big (stick legs and arms out, turning booties sideways, etc) we catch more air, increase drag and slow down the canopy's flight through the air. Similarly, by getting small, we penetrate the air better. These controls are more noticeable on the smaller canopies (where the jumper's drag is a significant component of the overall drag) and are useful if you are trying to fly in formation.

As an input it may not feel significant but when you add up all the small insignificant inputs (collapse slider, open chest strap, collapsible pilot chute, etc) they can mean the difference in getting back from a long spot and not getting back.

[cessna54tango 0]

"(collapse slider, open chest strap, collapsible pilot chute, etc) "

remove slider, open chest strap, remove pilot chute........

[NewClearSports 0]

I really agree with you. Body position as well as body drag has a big effect. And this is really interesting in itself.

For instance, I'm a tall skinny guy, which means I don't weigh much, but have alot of surface area. I notice a considerable difference when diving my canopy (Xaos 88) after a Freefly jump (High Drag Freefly Suit) VS. when doing a hop and pop in a T and Shorts.

I often wondered exactily how this is effecting my swoop. For example when I'm in a steep dive and the canopy and myself are horizontal relative to each other racing for the ground conected by our lines, one of us either has to slow down, or speed up to start the recovery arc. It is almost always the canopy slowing down (Letting up on the Front Risers) that begins the arc. BUT what if I could start the arc instead by ME speeding up ??? ie. I start the dive with my body fully extended and once into the dive close to Canopy Terminal Velocity, I ball up (Speed Up) and induce the recovery arc phaze in that manner. This would certainly seem more effeciant.
I also certainly think this will be more of an issue with smaller and smaller canopys. It would be interesting to find out the effects of body position (Body Drag) on a very small wing like Lugi's 39. Supose there is another pilot out there same weight as Lugi but is 6' tall. Could he also land the parachute the same as Lugi? I doubt it!

Any other thoughts on this?

Please join in.

[NewClearSports 0]

Any wing can stall at any airspeed and at any attitude.


Really? This leads me to believe that Stalling is a random event. If I believed that I would never fly.

I'm not sure what I'm missing, but don't we try to fly at airspeeds and attitudes that will NOT allow us to stall?

[NewClearSports 0]

CRWdogs use that trick all the time. Its called warping the canopy, and severely degrades the performance. Very useful trick for when you need to make your canopy slow and sinky!


Is it safe to try with a small HP X braced Canopy?

[faulknerwn 36]

I used to do it all the time on my Cobalt 75 (loaded ~2.1). It worked fine. Just play with it up high.

W

[CanuckInUSA 0]

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Any wing can stall at any airspeed and at any attitude.


Really? This leads me to believe that Stalling is a random event. If I believed that I would never fly.

I'm not sure what I'm missing, but don't we try to fly at airspeeds and attitudes that will NOT allow us to stall?

With that attitude it is clear that you have never been trained as an aircraft pilot and know little about aerodynamics. Yes read that again and understand it and understand that a stall is NOT a random act.

A stall occurs when the flow of air is disrupted over the top of the wing. Most of the time the stall occurs because as our airspeed decreases, we increase the angle of attack in relation to the relative wind and sooner or later the decreasing airspeed + increasing angle of attack is too much and the flow of air is disrupted. But the wing can still stall at any airspeed or at any attitude. Too many skydivers think that a canopy will only stall when you pull down your toggles. Unless you're pounding in your landings, you're stalling your wing on every landing even if you land on your rears or even if you don't even finish your flare.

Obviously we as skydivers do not fly our canopies the same way an aerobatic pilot can fly their airplanes and thus many of the stall scenarios they may experience are not applicable to ourselves.

So where does this statement apply to swooping?

As an example, you're in the middle of your turn hurling towards the planet. You initiate your recovery and let's for the sake of argument say that you're on your rears during this initial recovery phase while you approach some sort of target and/or entry gate. But you realize you're low and for whatever reason you try and dig yourself out on your rears and you do this too abruptly. Airspeed isn't an issue here since you're just dived the canopy from hundreds and hundreds of feet above the deck. But by changing the attitude of the wing too abruptly, you run the risk of disrupting the flow of air across the top of the wing and run the risk of stalling at too high of an airspeed (plus why do you think a wing will stall at a higher airspeed when you're in a turn and/or landing using only your rears versus toggles, ... landing on toggles is analogous to an airplane pilot who uses flaps ... flaps allow the wing to fly at a slower airspeed).

Once again if you don't believe me, maybe it's time you take some aircraft flying lessons or better yet get someone to explain how aerodynamics works. You're clearly a danger to yourself if you think otherwise.

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

[brokky 4]

With rears you don´t only change the angle of attack of the wing.By applying too much rear riser you actually destroy the airfoil itself ( pulling down only the C and D lines ).That´s why rear risers are only effective with minimal input.
In the future we will see better canopies but also better risers ( For example 4 risers per side with a gradual system like some paragliders have...)

wuk??

http://www.brunobrokken.com

[cessna54tango 0]

"But by changing the attitude of the wing too abruptly, you run the risk of disrupting the flow of air across the top of the wing and run the risk of stalling at too high of an airspeed (plus why do you think a wing will stall at a higher airspeed when you're in a turn and/or landing using only your rears versus toggles, ... landing on toggles is analogous to an airplane pilot who uses flaps ... flaps allow the wing to fly at a slower airspeed). "


exactly, this is called a high speed stall and also happens in aircraft. as for the flaps the reason they help the plane fly more slowly as they add more surface area to the wing. as they extend outward they add more surface area, as they move down they increase the camber, or curvature of the airfoil. this tricks the wing into thinking you are at a lower angle of attack. using a 182 for example, you can land no flap pretty slow, but you will be very nose high to fly this slow. ive hit the tie down ring on the tailcone before using 40 degrees of flaps will be able to fly slower and make the landing less nose high. i dont like to use flaps to describe how toggles effect the tarp, while they work similar they dont work exactly as they do on the anti gravity machine.

[Pulse 0]

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Too many skydivers think that a canopy will only stall when you pull down your toggles. Unless you're pounding in your landings, you're stalling your wing on every landing even if you land on your rears or even if you don't even finish your flare.

With a proper weight-transfer on landing, I don't know if I'm ever reaching a full stall. Example:

1- Start flare
2- 'Place' feet on the ground, lightly.
3- Slowly start getting your weight on your feet
4- As more weight transfers to your feet, your canopy's wing-loading decreases.
5- Wing-loading decreases, stall speed decreases.
6- This continues until you are at a stop.

I guess I you do stall at the very end of your weight transfer. But the trick is to do it so the stall in imperceptible.

"Any language where the unassuming word fly signifies an annoying insect, a means of travel, and a critical part of a gentleman's apparel is clearly asking to be mangled."

[NewClearSports 0]

Any wing can stall at any airspeed and at any attitude.

Ok, after refreshing myself on Brian's Parachute and it's pilot book I now see where I was confused.

The attitude of the wing is not always directly related to it's angle of attack, although most of the time it is to some degree.


For other's like myself that were confused by this statement if you pull your rear risers you can increase your angle of attack without changing your attitude, and a high enough Angle of attack will create a stall at .... Any Airspeed or any attitude.

Ahh - ha . So I got it now.
Am I safe to start flying my parachute again?

How is that 96 Velo I sold you doing?
I'm waiting on my new 84 JVX hybrid.

Cheers
Mike

[NewClearSports 0]

P.S.

In reguards to these little parts of your blurb.

...With that attitude it is clear that you have never been trained as an aircraft pilot and know little about aerodynamics

...You're clearly a danger to yourself if you think otherwise.


I like your statement

Try not to worry about the things you have no control over
"Less bitching, more jumping"

Practice what you preach.
I gave up on this forum a few years ago because of stuff like this. To all the guys that have to throw this type of crap into every topic, your not doing anthing good for this sport.

[CanuckInUSA 0]

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How is that 96 Velo I sold you doing?

You must be confusing me with someone else.

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

[Canuck 0]

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How is that 96 Velo I sold you doing?

That's this Canuck you sold it to. Still have it, but it's in my back-up rig now. Still flies great, even with the 1000 plus jumps that are on it!

[LearningTOfly 0]

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as for the flaps the reason they help the plane fly more slowly as they add more surface area to the wing. as they extend outward they add more surface area, as they move down they increase the camber, or curvature of the airfoil. this tricks the wing into thinking you are at a lower angle of attack.

Some flaps do in crease area, some don't: Fowler flaps will increase area to a certain extent (guess, 2-8%); Split flaps... don't.

I don't know that the flap does any 'tricking' at all. Nor do they reduce angle of attack. Lowering a flap over a portion of the wing will actually increase the effective angle of attack that the flapped portion of the wing is subject to compared to the non-flapped portion. That is to say, the unmodified section of your wing will be flying at an AOA of 7 degrees while simultaneously, the flapped portion will be at an effective AOA of 8.5 degrees (ballpark, the idea is there at least). Deploying a flap increases the camber of a wing, which increases the wing's coefficient of lift, which means that it is capable of producing greater lift for a given airspeed. That's why you can plane out and swoop two feet off the ground for a hundred feet, while decelerating- because you're continually deploying more 'flap' with decaying airspeed, thus keeping your lift force at 180lb ...or whatever number you happen to weigh.