Canopy collision

[diverdriver 5]

John,

I hardly ever read this forum and hadn't heard about this happening from the usual suspects. Dang dude I'm glad you're ok. Seems we have learned nothing in this sport. The guy still insisted that you hit him and it wasn't his fault even after witnesses on the ground told him otherwise. How many jumps and what kind of experience did this other guy have? What kind of canopy and wingloading did the other jumper have?

Roger must have been looking over you. That and you chose a docile 7 cell canopy rather than a pocket rocket hanky. It definitely saved your ass imo.

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[piisfish 140]

quick question...

How tight is your chest strap.. Seems hard to say like that but it seems your risers are quite close at the bottom.

Do you think a wider chest strap and a lowered slider would have helped minimize/diminish the effects of the collision regarding the linetwists ?

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[Trae 1]

Lucky boy!


Just wondering now if going to a slower canopy is still the idea to reduce risk. ??

If going to a slower chute allows faster ones to sneak up unseen from behind then this adds a risk dimension.

Thanks for demonstrating this so well.
& Glad you're good.

[diverdriver 5]

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Lucky boy!


Just wondering now if going to a slower canopy is still the idea to reduce risk. ??

If going to a slower chute allows faster ones to sneak up unseen from behind then this adds a risk dimension.

Thanks for demonstrating this so well.
& Glad you're good.

Let's see, Roger Nelson was on a small cross-braced canopy and pulling a high performance landing when he was hit from above and behind by another jumper under a small cross-braced canopy which collapsed his and he died from the ensuing spiral and impact.

John chose a docile 7 cell canopy and when struck causing line twists at by some estimates below 100 feet he was able to recover and walk away from the landing. I'd say John made the right choice.

The canopy collisions happen anyway. The collisions didn't START happening by slower canopies.


edit: Trae, I guess after re-reading your post I'm not sure if you are opposed or for people going back to more docile canopies. Is that your view that the slower canopy choice caused this collision?

Chris Schindler
www.diverdriver.com
ATP/D-19012
FB #4125

[kallend 2,027]

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quick question...

How tight is your chest strap.. Seems hard to say like that but it seems your risers are quite close at the bottom.

Do you think a wider chest strap and a lowered slider would have helped minimize/diminish the effects of the collision regarding the linetwists ?

Following the advice of a former RW champion who now owns the company that made my rig, I keep my chest strap tight during freefall. I loosen it under canopy, as soon as I have clear air. So at the time of the collision it was loose. I don't like pulling my slider over my risers on big ways, too much chance of something jamming or getting dislodged. So I have slider stops over the slinks.

Finally, I don't think it would have made an ounce of difference.

...

The only sure way to survive a canopy collision is not to have one.

[mjosparky 4]

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Seems hard to say like that but it seems your risers are quite close at the bottom.

That will usually happen if you cross the risers and load them, take the left and pull it to the right, take the right and pull it to the left. I think this would happen if the chest strap was not hooked up.

My idea of a fair fight is clubbing baby seals

[rehmwa 2]

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even after several of us told him it was his fault he insisted otherwise.

This is pretty common when "several" people converge on one guy and start lecturing him. (even if deserved, little good comes from it).

For learning, best bet is to let both parties cool down from the adreneline rush and then one witness share what they saw. Also, out of the public eye it's easier for the parties involved to accept whatever fault is there and learn from it - instead of drawing back into a defensive posture immediately and publicly with a bunch of wide-eyed spectators all pitching in their 2 cents.

Low whipping turns to final in a crowded pattern always sucks.

Another reason video is such a great thing.

I like the prof, glad he was ok. His response about 2 in an accident and 1 to avoid is the most mature thing I've read in a very long time. Another reason why he's still skydiving.

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[Trae 1]

in reply to "I'm not sure if you are opposed or for people going back to more docile canopies. Is that your view that the slower canopy choice caused this collision? "
.....................

I'm not decided about slower is safer given the mix of canopies in the sky.
I suppose fast canopies can go slow in the landing circuit and get snuck up on too.
However slower canopies generally tend to open better and give more time for decisions even though they suck a bit when the wind gets up..

My view is the faster canopy caused this incident... pilot error.
kallend's choice of docile canopy in this situation possibly added to the danger by being a big slow target as well as diminishing it by being so stable after the collision.

Do you go fast enough to keep out of their way ?
or be bullet proof if/when they do hit you?

or both

[JohnMitchell 16]

How about the faster canopies watch out where the hell they are going? Should the students and tandems get the hell out of the way for all the swoopers? Quit trying to place the blame where it shouldn't go. I respect Kallend's opinion, but I think you can do everything right and still get hit by someone going faster than the traffic really allows.

I'm lucky to jump with some really good swoopers that will respect the slothful flight of my 1.5 loaded Stilleto. Canopy collisions are all avoidable, but only if it's everyone's goal.

[mjosparky 4]

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but I think you can do everything right and still get hit by someone going faster than the traffic really allows.

Or by someone going faster than their abilities allow. I have seen students on the ground picking up their canopies almost get taken out by a would be swooper.

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I'm lucky to jump with some really good swoopers that will respect

The drop zone I jumped at had some of the best swooper in the world. And I can't remember where they ever had a conflict with another jumper in the landing area. The really good ones don’t create problems and the want to bee’s blame it on everyone else when they do.

The Prof. said it takes 2 to cause and 1 to avoid. That’s all well and good and sounds noble. But in the real world it is usually caused by one person flying with their head up their butt.

My idea of a fair fight is clubbing baby seals

[kallend 2,027]

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in reply to "I'm not sure if you are opposed or for people going back to more docile canopies. Is that your view that the slower canopy choice caused this collision? "
.....................

I'm not decided about slower is safer given the mix of canopies in the sky.
I suppose fast canopies can go slow in the landing circuit and get snuck up on too.
However slower canopies generally tend to open better and give more time for decisions even though they suck a bit when the wind gets up..

My view is the faster canopy caused this incident... pilot error.
kallend's choice of docile canopy in this situation possibly added to the danger by being a big slow target as well as diminishing it by being so stable after the collision.

Do you go fast enough to keep out of their way ?
or be bullet proof if/when they do hit you?

or both

My canopy is a Spectre 135. Docile, yes, but not particularly slow. It's not like I was on an accuracy canopy or a Manta. Quite appropriate for big ways, I think. It wasn't a swoop event.

...

The only sure way to survive a canopy collision is not to have one.

[riggerrob 643]

My view is the faster canopy caused this incident... pilot error.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Rules of the road hold the higher, faster canopy responsible for avoiding other traffic.

[Trae 1]

in reply to "My canopy is a Spectre 135. Docile, yes, but not particularly slow. It's not like I was on an accuracy canopy or a Manta. Quite appropriate for big ways, I think. It wasn't a swoop event. "
...............................................

Mmmm . I've been considering changing to a more docile canopy myself .
However these collision issues ( as well as bad spot, wind issues) just won't go away.
On perfect skydiving days medium performance canopies would be no worries but when the conditions marginalise it'd be less fun. I suppose a 2nd rig would solve this prob.

Winding back on the inexperieced people under hot highly loaded canopies could reduce the prob .etc.etc...

.... the sport aint got on top of that one yet

[itllclear 1]

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There is no shame in walking a little bit further.

REMEMBER THAT.

Yes, I was shouting.

Having a canopy collision because you were going for the "main" landing area when there are acres of flat land all around is stupid.

"Harry, why did you land all the way out there? Nobody else landed out there."

"Your statement answered your question."

[billvon 2,995]

>kallend's choice of docile canopy in this situation possibly added
>to the danger by being a big slow target . . .

A sky full of slower canopies is _not_ the same as a sky full of faster canopies when it comes to avoiding collisions. Larger canopies turn slower, fly slower, and give their pilots (and the pilots near them) more time to avoid collisions. You're pretty much always better off from a traffic perspective adding slower canopies to a pattern, even if most of the other canopies are fast.

>I suppose fast canopies can go slow in the landing circuit

But they cannot slow down as much as the slower canopies.

[kallend 2,027]

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My view is the faster canopy caused this incident... pilot error.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Rules of the road hold the higher, faster canopy responsible for avoiding other traffic.

Being right doesn't bring anyone back from the dead. Still need to keep a good lookout, especially when it's crowded.

...

The only sure way to survive a canopy collision is not to have one.

[Trae 1]

in reply to "You're pretty much always better off from a traffic perspective adding slower canopies to a pattern, even if most of the other canopies are fast. "

........................

uh huh, but is it better (as in safer from collision ) to be under one of the slow ones or faster ones?

If every-one was going slow then not so big a prob.
Insert speedy parachutes = added issues.

I'm reminded of some early stilletto advertising along the lines of " carve your way through the turkeys "'

Now it seems more like look out for the turkeys carving their way through .

[billvon 2,995]

>uh huh, but is it better (as in safer from collision ) to be under one
>of the slow ones or faster ones?

Slow ones. You have more reaction time, and you have a larger range of survivable speeds available for landing. If someone collides with you and damages your canopy, you are better off with a larger one.

>If every-one was going slow then not so big a prob.
>Insert speedy parachutes = added issues.

Definitely true.

[freakydiver 0]

Are you serious?

-- (N.DG) "If all else fails – at least try and look under control." --

[Trae 1]

in reply to "Are you serious? "
..................

Mmmm let me see ................




Yep

[popsjumper 2]

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..Now it seems more like look out for the turkeys carving their way through .

From what I've seen (excepting the newbies, of course), it's the rocket-men that are being the "turkeys".

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[freakydiver 0]

I'm sure you realize this but there will ALWAYS be slower "targets" in the sky as you put it. Perhaps I am just confused by your statements.

-- (N.DG) "If all else fails – at least try and look under control." --

[Trae 1]

in reply to "I'm sure you realize this but there will ALWAYS be slower "targets" in the sky as you put it Perhaps I am just confused by your statements. "
...............

Sure and perhaps.

The choice/issue here for me is between-

:- having a slower more docile easier opening canopy that is slow in the landing circuit.
& flying a HP canopy that has more challenging openings but goes where you want it to fast and is exhilarating to fly.

The pro's for each type are good.
Slow may be safer in some ways whereas fast can provide extra safety in some situations eg bad spot.

The cons . Fast is unforgiving . You may be able to dodge better under a fast canopy but this advantage is offput by things happening quicker.
Going slow can be dangerous in some situations. eg bad spot,
Getting caught amoungst fast canopies?... bit like riding a pushbike on a freeway.

Is slow safer than fast for experienced jumpers??? maybe ...... still undecided.

[billvon 2,995]

>whereas fast can provide extra safety in some situations eg bad spot.

The large canopy and the small canopy will give you the same landing 'footprint' i.e. you will be able to get to as large an area with both canopies. The faster canopy will reduce how much that footprint moves with wind. The slower canopy will result in survivable landings over a wider range of out landings.

There are a lot of reasons people jump smaller canopies, but extra safety is NOT one of them. It's like jumping a Nova because they open fast and are thus safer.

[MakeItHappen 15]

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The large canopy and the small canopy will give you the same landing 'footprint' i.e. you will be able to get to as large an area with both canopies.

This statement is ONLY true if the L/D for both canopies is the same.

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The faster canopy will reduce how much that footprint moves with wind.

Not true.
The wind shift depends on:
- the wind speed (assumed to be only horizontal)
- the amount of time spent in the wind (Dv/Vvc = initial altitude/descent rate)
- the horizontal component of the canopy system's velocity.

Downrange distance = (Vhc + W) * (Dv/Vvc)
Uprange distance = (Vhc - W) * (Dv/Vvc)
where
Vhc = horizontal canopy system speed
W = wind speed
Dv = initial altitude
Vvc = descent rate

Footprint = uprange distance - downrange distance

A LARGER canopy with a HIGHER WL (higher total speed) and a LOWER L/D will have a SMALLER footprint than a SMALLER canopy with a LOWER WL (lower total speed) and a LARGER L/D.

Think of tossing out a bigger payload out under a round parachute and then compare that to a smaller payload under a ramair.

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The slower canopy will result in survivable landings over a wider range of out landings.

This generalized statement is true.

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There are a lot of reasons people jump smaller canopies, but extra safety is NOT one of them.

Not true on this one too. I jump a smaller canopy at a higher WL than I really want to because I do not want the people from the plane after me to buzz me at landing. It is safer for me to jump a higher WL and to land with people from my airplane than to have the people from the next load under pocket rockets buzz me at 50 ft.

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