The rock point under canopy...

[rhino 0]

This is my brief explanation of the rock point under canopy. A couple of people PM'd me asking what I was talking about. If anyone "Hook" has a better way to describe it post away.

The rock point,

It is the point during the flare that you have swung directly under canopy. Where you have entered the slow speed flight of your canopies airfoil. At your rock point your descent has ceased and you are just moving forward bleeding off airspeed. Does that make sense?

Weight wise under canopy you have shifted slightly in front of your canopies center of gravity allowing the canopy essentially to canter upwards acting as a brake and slowing down.

In an airliner. When the plane slows down, flaps drop. The moment that nose starts to point above the horizon with the plane still flying straight and level could be considered the rock point.

That is when the energy of your wing becomes most important, the lift and speed. Your canopy is just like an airplane wing. You slow down, start to apply flaps "toggles" cantering the nose of your canopy upwards while still flying straight and level slowly applying more flaps "toggles" nose rising even more until the stall point of the canopy "where your feet should touch the ground".


Rhino

[quade 3]

I understand what you're saying, but the terminology and analogy to a powered airplane is a bit confusing.

Specifically, a powered airplane can be in level flight, neither climbing nor decending, with the nose of the airplane at any one of a number of angles relative to the horizon. In a Cessna 172 for example, that might be from 0 (right on the horizon) to pitched up as much as 15 degrees or so during any one of a number of modes of slow flight depending on the power settings.

Also, rather than saying "shifted slightly in front of your canopies center of gravity" a better phrase might be the canopy's center of pressure. Similar to the concept of center of gravity, the center of pressure is the point along the cord (line from leading edge to trailing edge) where the lift created by the wing is balanced.

So, what you're saying is that when fairly rapid toggle controls are applied, the skydiver's center of gravity swings more forward of the canopy's center of pressure. This is an example of the "dynamic" nature of canopy flight.

quade -
The World's Most Boring Skydiver

[andy2 0]

to get this straight (I love thinking about this stuff ever since I first flew a canopy), the "rock point" comes directly after the "hook" or whatever maneuvuer you do to build speed, the "descent" timing the "rock point" to happen as you are 1-3 feet off the ground. Correct? I hope that doesn't read as blabbering.

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let my inspiration flow,
in token rhyme suggesting rhythm...

[Samurai136 0]

Just fly the canopy. At your experience level you should be building basic canopy control skills.

Ken

"Buttons aren't toys." - Trillian
Ken

[raymod2 1]

> It is the point during the flare that you have
> swung directly under canopy. Where you have
> entered the slow speed flight of your canopies
> airfoil. At your rock point your descent has ceased
> and you are just moving forward bleeding off
> airspeed. Does that make sense?

No, that doesn't make sense. You can arrest your vertical descent at nearly any airspeed. This has nothing to do with "slow speed flight". To the contrary, the primary goal of a swooper is to plane out at the highest possible airspeed.

> Weight wise under canopy you have shifted
> slightly in front of your canopies center of gravity
> allowing the canopy essentially to canter upwards
> acting as a brake and slowing down.

The purpose of flaring (or rear-risering) is to increase the angle of attack in order to maintain lift while airspeed is decreasing. Yes, this also increases induced drag (canopy acting as a brake) but this is an (undesirable) side effect. Also, this is a continual process and not well described in terms of a discrete "rock point".

> In an airliner. When the plane slows down, flaps
> drop. The moment that nose starts to point above
> the horizon with the plane still flying straight and
> level could be considered the rock point.

Most planes can takeoff, fly their entire flight plan, and land without ever extending the flaps. Also, extending the flaps increases the angle of incidence so it is usually accompanied by a *downward* pitching motion. That is one of the reasons flaps are used on jump run. It allows the plane to slow down without pitching the nose up (and increasing the risk of exiting skydivers hitting the tail).

[rhino 0]

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To the contrary, the primary goal of a swooper is to plane out at the highest possible airspeed.

I said NOTHING of swooping. This is for those that don't know what the rock point is.

What I said makes perfect sense. You might not understand it but the principal is sound. And I am in fact correct.

Thanks for the help Quade. The plane thing was more for visual than anything.

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The purpose of flaring (or rear-risering) is to increase the angle of attack in order to maintain lift while airspeed is decreasing.

AGAIN, I wasn't talking about THE FLARE. I am specifically explaining what the rock point is. Start a flare thread if you want to and try and stay on the topic. Maybe we are finding out you don't even know what the rock point is. The rock point is maybe 1/20th of the flare process. It is something that you pass during the flare.

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Most planes can takeoff, fly their entire flight plan, and land without ever extending the flaps.

It wasn't the best example but effective for visual sake.

Rhino

[ManBird 0]

You should also mention the sponge slide. It's the point under canopy where you feel special. REALLY special.

"¯"`-._.-¯) ManBird (¯-._.-´"¯"

Click

[Michele 1]

Thanks, Rhino. I think I know the point you're referring to, but I am not positive. I will do what I can to "feel" it on my next jump. Appreciate you taking the time to write it out!

Thanks!

Ciels-
Michele

~Do Angels keep the dreams we seek
While our hearts lie bleeding?~

[raymod2 1]

> I said NOTHING of swooping. This is for those that > don't know what the rock point is.
>
> What I said makes perfect sense. You might not > understand it but the principal is sound. And I am > in fact correct.

The purpose of my post was to demonstrate that you were talking straight out of your ass and that you don't have a clue about the basic principles of flight. I think I succeeded at that.

[rhino 0]

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The purpose of my post was to demonstrate that you were talking straight out of your ass and that you don't have a clue about the basic principles of flight. I think I succeeded at that.

No in fact you failed.....

Vain attempt at best. Again stay on topic. You have more than proven that you don't have a clue as to what the rock point is, so take notes, do some hop-n-pops and realize that you don't know everything.

If I am talking out my ass I guess Charlie Mullins and Hooksnswoop are both full of shit. Because I learned from them.

PAY ATTENTION. It might make you a decent canopy pilot.

And considering the fact that you fly a sabre150 you might not want to get into swooping discussions either.

Be safe.

Rhino

[SkymonkeyONE 3]

Exactly what does him flying a Sabre 150 have to do with him not being able to swoop? A decade ago, 150's were very small parachutes. We swooped the piss out of them.

Chuck

[andy2 0]

[QUOTE]fly a sabre150 you might not want to get into swooping discussions either.[/QUOTE]

I'm not a very smart man, but I know that you don't need a small canopy to swoop. Its attitudes like this that promote downsizing before one really masters a canopy. Already after only 2 months in this sport, I have met up with this type of attitude. It's wrong! And detrimental to OUR sport!

---------------------------------------------
let my inspiration flow,
in token rhyme suggesting rhythm...

[rhino 0]

We can start a swooping thread. lol

The sabre has a short recovery arc. It is not designed to swoop. You can swoop a manta 300, that doesn't mean it's a good idea.

Rhino

[rhino 0]

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I'm not a very smart man but I know that you don't need a small canopy to swoop.

That is a harsh thing to say.

And you are right. I said nothing of downsizing. It's canopy type. It involves recovery arc, wing loading, wing type and performance variables.

If you would like me to explain to you why a sabre isn't a swoop canopy "considering we live in the here and now, not 10 years ago" pm me and I will explain it to you the same way it was explained to me when I bounced under my Triathlon150 loaded at 1.25.

The Triathon isn't meant to be swooped. Neither is a sabre. Now that I am on a wing that has a longer recovery arc I understand why. It isn't something I could have possibly understood while under a Triathlon. It is something you have to feel.

If you don't want my info ask hooksnswoop. He saw me drill in under my triathlon and was one of many that CHEWED my ass about trying to hook that type of canopy.

Can it be done.. Sure. It is argued that the shorter the recovery arc the less room for error you have.

And Chuck, I wouldn't dare say that you don't have the skill to swoop a sabre loaded at .8. You are a pro-swooper and I am not. How ignorant would that be for me to say.

My post was directed at the individual that didn't understand a rock point, said I was talking out my ass, and has probably never initiated a hook over 300 feet.

Rhino

[SkymonkeyONE 3]

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We can start a swooping thread. lol

The sabre has a short recovery arc. It is not designed to swoop. You can swoop a manta 300, that doesn't mean it's a good idea.

Rhino

Another totally incorrect reply, Rob. The Sabre was designed as a performance canopy. It was the replacement for the crossbraced, tri-cell F-111 Excallibur. It was absolutely designed for swooping and performance maneuvers. Once again, believe me when I tell you that we all swooped the living shit out of Sabres. We had no choice, because PD refused to make us zero-P Excals to replace the worn out ones we all had in our rigs.

Yes, a Sabre has a much shorter recovery arc than a modern performance nine-cell or crossbrace. No, you can't arbitrarily discount them as a performance or "swoop" main just because times have changed. Underestimating the potential of a relatively small zero-p main is what gets people hurt. Thinking a Sabre 150 is a good first main would have drawn howls from us not long ago. All this is completely beside the point of the thread, but your comment gone unchecked would have led others to believe that what you said "must be the right."

Chuck

[rhino 0]

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Yes, a Sabre has a much shorter recovery arc than a modern performance nine-cell or crossbrace.

Fair enough.. Some people do swoop sabres. Would I? No. Would anyone I have gotten canopy training from? No.. To each his own I guess. People that trained me would agree with what I am saying where recovery arc is concerned. It is a split crowd I guess.

Thanks for your mojo Chuck

Rhino

[CanuckInUSA 0]

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Would anyone I have gotten canopy training from? No..

Ok I'm not all that experienced yet in the fine art of high performance landings but what you just said here isn't true. Hooknswoop (who it sounds like has trained you a little just as he's trained me a little) occasionally flies a 170 Saffire (similar to a Sabre) and while we know his swoops on this canopy aren't as gnarly as his XV swoops, I'm sure he can still swoop the sucker.

Now I understand the recovery arc and yes also the rock point (once again some of my knowledge is thanks to Hook some of it has to do with the fact that I was a pilot before I was a skydiver) and I am a Sabre2 canopy pilot. Of course my swoops aren't all that impressive compared to someone more experienced and someone who's flying a canopy designed to swoop. But when I land in low to no winds here in CO, I can easily swoop 100 feet (maybe even more, I don't know, I've never really measured it). I'm not trying to be confrontational, but any canopy can be swooped. Some are just designed better than others for this art.

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

[rhino 0]

He owns a safire 189 I think? I jumped it.

As him if he hooks it or makes a habit of it or if he would recommend hooking that canopy at that wing loading to someone trying to learn to hook..

I didn't say ask him of he can. I said ask him if he does. Of the probably 20 hooks I watched him make last weekend I don't recall seeing him hook anything but his vx-60.

I could hook his 189. Would I ever? No. Based on a conversation him and I had it would be going against his advice given to me.

Rhino

[rgoper 0]

i've steered clear of this one until now. all i have to add is i think there's a bunch of sky diver's that need to
"check the ego" at the door. there are many differing methods of canopy control, and although they may be different in style, or termonology they all can work. but, what do i know? i've got over 500 sky dives with out so much as a scratch, but i can wind up in the "incidents" forums just as quickly as any here.

Edited to add:

i don't need any advice or sky diving class to make me aware of my last statement, that much i'm sure of myself.

--Richard--
"We Will Not Be Shaken By Thugs, And Terroist"

[Piru 0]

I Swooped a sabre 150 at 1:1 wing load and i consider tha satisfatory for me. I have video-taped it. I saw something about a Tri-cell Excaliur cross-braced i have one with me. I will jump with it again.

Piru