Weird Canopy Behavior

[katzurki 0]

Please watch the video (2mb, WMV). What do you think would cause the canopy to behave so weirdly?

(Gear: clapped out 350-jump Troll 265 MDV, WSX)

[piisfish 140]

it seems in my inexperienced eyes that the canopy doesn't get forward speed. Can it be due to turbulence because of the building ?

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

[katzurki 0]

I don't think so because the other jumpers had nice smooth flights to where the cameraman is, I just excluded them from the video for size purposes.

Basically, the canopy never gets any forward speed despite the jumper having unstowed the toggles, and just drops straight down.

I have yet to get the jumper's impression of what happened, though.

[460 0]

What were the local winds doing? You look like you are in a perpetual stall. Have you inspected the canopy?

Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[katzurki 0]

There was a light, think 6-8 MPH, crosswind.

[gweeks 1]

It's hard to tell from the video because you can't really see what inputs the pilot is putting and what the canopy is doing on its own. That said, it looks like the left steering line is hung up and the pilot was fighting a built in left turn the whole time. Perhaps the toggle release wasn't clean? The canopy turns to the left on opening. The pilot corrects by pulling down the right toggle, but because the left side is already so far down this almost stalls the canopy. The pilot then lets up the right toggle and the turn starts again. The pilot then semi-flares and almost stalls again on landing.

I've had a brake setting hang up before when I've been lazy releasing them. That would be my guess.

[vid666 0]

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It's hard to tell from the video because you can't really see what inputs the pilot is putting and what the canopy is doing on its own. That said, it looks like the left steering line is hung up and the pilot was fighting a built in left turn the whole time. Perhaps the toggle release wasn't clean? The canopy turns to the left on opening. The pilot corrects by pulling down the right toggle, but because the left side is already so far down this almost stalls the canopy. The pilot then lets up the right toggle and the turn starts again. The pilot then semi-flares and almost stalls again on landing.

I've had a brake setting hang up before when I've been lazy releasing them. That would be my guess.

it looks like there is right rear RISER input vs. toggles. But like Gregor said I too have had the cats eye hangup on the white loop on a lazy toggle release. At that point canopy got almost no forward flight, just rotation around the axis and nice sink. And that was on almost new Mopheus risers.

[gweeks 1]

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it looks like there is right rear RISER input vs. toggles. But like Gregor said I too have had the cats eye hangup on the white loop on a lazy toggle release. At that point canopy got almost no forward flight, just rotation around the axis and nice sink. And that was on almost new Mopheus risers.

You're right about riser vs. toggle. You can see the right side of the canopy from the c lines back get pulled down when the pilot makes his input. Good catch.

[BetteSimon 0]

I would say it looks like the right toogle is allready popped in the opening, and that makes the canopy turn left. He then tries to make up for that with a right rear riser input. That turns the canopy, but at the same time puts it into a stall. He never really gets out of that, and that is why he never gets any forward speed. Maybe he should consider having a bit shallower DBS made.
Just my opinion..

[jraf 0]

There seems to be another building right next to the jump object, with a narrow space in between them. It apears to me that the jumper might have been caught in a draft coming through that narrow opening. We all know how weird canopies react close to objects were winds and different temperatures play tricks.

To me it appears that the canopy also deflates to a degree. Once again I would attribute it to the weird draft coming from between the buildings.

Last issue: how is the jumper? It looks like he hit the ground quite fast.

jraf

Me Jungleman! Me have large Babalui.
Muff #3275

[base736 0]

Especially for a jumper in brakes, 6-8 mph could be plenty of wierdness to cause this kind of behaviour. I jumped into a tight canyon once and, coming in 30 feet over the landing area in brakes with a bluff behind me, I suddenly felt myself getting pushed backward into the bluff (and dropped into the ugly streambed below). I let the brakes up slowly and made the snowbank on the far side.

Anyway, there was very little wind that day. Doesn't take much if you're in a braked turn or something.

Edit to add: The other two jumpers who followed me on that one had no problems at all.

[audacium 0]

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Please watch the video (2mb, WMV). What do you think would cause the canopy to behave so weirdly?

(Gear: clapped out 350-jump Troll 265 MDV, WSX)

Hello,


I would opt for a deep stall, especially reading it was a clapped out canopy. Porosity might have gone up so much that the canopy, once in deep stall, does not come out of the deep stall by itself because too much air goes through canopy and flow over profile cannot pick up.

Probably it was induced by the toggle / riser input, but then the slight kink in the canopy, while fully open, and the straight sink with that sink rate look to me like a deep stall (and not full stall).


Eduard.

--
Eduard

[marinho 0]

Hi,
Is it possible that the jumper pull the right rear riser thinking he's pulling the toggles?
Is it possible that he pulled the toggles and for some reason the right one got stuck on the cateye/brake loop and he thought he's pulling the toggle?
That canopy somehow just had the right rear riser pulled down in my opinion! Off course it looks bad because the short time the jumper had to fly the canopy!
I hope this helps!
Cheers,

Gus Marinho

[yuri_base 1]

Looks like he lost the right toggle: the tail is flapping as there's no tension on it.

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[crwper 7]

Once the canopy is fully inflated and turning a bit, it seems clear that the right side of the canopy is in full flight, and the left side is partially braked (looking at the tail).

What also seems clear is that the jumper is using a lot of right rear riser to counter the turn. If the brakes were set very deep to start with, and just the left brake was left stowed, then countering with the right rear riser will likely stall the canopy, which is consistent with what we see.

So I'd say the proximal cause of the problem is that the jumper is stalling the canopy by countering the turn with the right rear riser while the left toggle is still set in deep brakes.

I don't see a toggle trailing behind the canopy, so I assume the right toggle is in the jumper's hand. In that case I see two options: Either the left toggle was never released (possibly the jumper responded to the left off-heading by popping the right toggle, but then switched to the riser), or else the left toggle was released, but (as others have suggested) the white loop never cleared the line.

I suppose it could also be a tension knot on the left side of the canopy which is preventing the brake lines on that side from extending.

Michael

Edited to add: Yuri has a point. When the right rear riser is applied, it should pull the brakes down a bit, too, right? Although I can't see anything trailing behind the canopy, perhaps the jumper blew the right toggle on opening. Realizing the canopy was turning left, the jumper countered with right rear riser. However, that could easily stall the canopy, since the left side is still set in deep brakes. There really isn't a lot of time for the jumper to realize the left brake is still set.

[bps 0]

Yuri is right -- the jumper lost the right toggle. If you look closely, you can see the right-hand side upper control lines flapping around (but not the toggle). And of course, the deformation in the tail when he performs an evasive manuever with his rear riser is another dead give away.

From the behavior of the pilot chute, and then the canopy at time of opening, it looks like there is a cross-wind from jumper's left to jumper's right. He lost the right-hand toggle (for whatever reason), corrected his heading after the canopy turned 100 degrees and then let up on the riser. He found himself turning again and then gave further input with the right-hand riser (to avoid strking the building) and landed at the base of the object.

Looking at the canopy flight, I don't think the jumper ever released the left toggle, but I cannot tell by looking at the video, so it's hard to say.

That is my 2 cents from watching the video...

Bryan

[katzurki 0]

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Last issue: how is the jumper? It looks like he hit the ground quite fast.

The jumper is unhurt, and very much unsure of what happened. He says he can't really remember what he was doing because the whole crew got busted shortly after the jump, and he was a bit overwhelmed.

Thanks for the input, guys! I learned a lot of interesting things.