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tdog

Two canopies out - anyone know of test jumps?

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Here is the deal...

The USPA SIM instructs to release the toggles on the dominant canopy and fly with the toggles.

Many jumpers I know - including our DZ policy for FJC students says - keep the brakes stowed and fly with the rear risers of the dominant canopy... The logic being - why cause one canopy to out-fly another - taking a stable situation and making it worse...

I know everyone has an opinion on this, (including myself) but I am hoping there is some real data to base policy on because opinions make shitty policy - i.e. test jumps - where someone has tried both and reports on real world data... Brakes stowed and rear risers vs pop the toggles...

Anyone know of a study or someone I can contact???

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>Many jumpers I know - including our DZ policy for FJC students says -
>keep the brakes stowed and fly with the rear risers of the dominant
>canopy...

Problem with this is that most new jumpers do not know they have a two-out until the reserve starts bumping into the main. How many times have you opened and looked behind/below yourself before unstowing the brakes? It's not someplace we normally look - but if you have a cypres firing during the very end of your main deployment, that's where it will be.

Thus most of the time newer jumpers will discover they have a two-out after they release the brakes - so it can make sense to teach a scenario in which that's how you fly the canopies.

If you do notice, I'd leave the canopies alone as much as possible - which means not releasing brakes.

Derek (poster here) did some experiments a while back and found that two similarly sized canopies tended very strongly to stay together in a side-by-side. The military also did a study a while back with large (i.e. student sized) canopies and found the same thing. Personally I have seen more problems with people cutting away from a two-out than from trying to land them together.

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Derek (poster here) did some experiments a while back and found that two similarly sized canopies tended very strongly to stay together in a side-by-side. The military also did a study a while back with large (i.e. student sized) canopies and found the same thing. Personally I have seen more problems with people cutting away from a two-out than from trying to land them together.




Derek as in Hooknswoop... If so, we are friends, so pony up Derek... (simon says he will read this thread in 24 hours or less)... Lets take a bet on how long...

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Didn't the Golden Knights do a bunch of test jumps like that years ago?

Yes, they did. Tom Hili, a WA jumper, did a bunch of those. he briefed our DZ on what they learned about the time we were moving our students to square reserves. The PD and USPA doctrine and recommendations drew heavily on the Knights' research.

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Didn't the Golden Knights do a bunch of test jumps like that years ago?

Yes, they did. Tom Hili, a WA jumper, did a bunch of those. he briefed our DZ on what they learned about the time we were moving our students to square reserves. The PD and USPA doctrine and recommendations drew heavily on the Knights' research.



Do you remember why they said toggles were better than rear risers and keeping the brakes stowed???

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Remeber if breaks are stowed canopies are flying slower.

If you unstow 1 set of breaks you make one of the canopies fly faster. Why to disturb a stable flying set of canopies?



My point exactly - however the USPA and apparently the Golden Knights have real data to support otherwise???

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Personally I have seen more problems with people cutting away from a two-out than from trying to land them together.



I was taught (and have heard elsewhere) that a bi-plane (1 in front of the other) if stable should be steered gently on the brakes of the dominant canopy (although I now agree risers may be better) BUT if they are side by side and the risers are clear then disconnect rsl (if you've got one) and chop the main. I believe the thinking is that a side by side is much more likely to develop into a downplane than one in front of the other.

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>I believe the thinking is that a side by side is much more likely to
>develop into a downplane than one in front of the other.

Derek's tests revealed that it was very, very hard to force a downplane; they wanted very badly to return to a stable side by side.

I teach a simpler approach. If it's controllable and will land you safely, stay with it. If not, try to separate the canopies, then cut away the main.

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i am relativly new to this sport and finished aff a little while ago, when i was going through the course i was told to fly the main by the toggles and leave the reserve alone. i was also told that it depends on the canopys you are fly as to wich type of formation the canopys will fly in bigger-biplane or side by side. the smaller you go-downplane is there any truth to this?
light travels faster than sound, that's why some people appear to be bright until you hear them speak

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Only two actuals I know of beyond the PD and Golden Knight reports...

Glenn Bangs report to the PIA Symposium of his two-out / instant downplane a last year (happened to him at the local DZ while the rest of us were in a seminar on what to do if you have two out... guess he shouldn't have been playing hookie... ;))

My own two-out during an airshow... long story short had a bumpy bi-plane (big canopies) that were going to get me into power-line trouble. Chose to chop (main in front), and in my case it cleared just fine.

I recommend reading BOTH reports, consider the relative and absolute sizes of canopies used in the testing and think through your options with your specific canopies.

Jim
Always remember that some clouds are harder than others...

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In class and on the malfunction video, they stated that the only two out situation that should be landed is a bi-plane. Obviously each individual situation merits its own evaluation and decision. There is no cookie cutter what to do answer. But if they're side by side, what would you do if they started to down plane at 100 or 50 feet?
I've always been told two is not better than one. Everyone, including my S&TA, who saw the event said I did the right thing. If you've got another take on it, by all means, my ears are open. If I wasn't here to learn, I certainly wouldn't be browsing the S&T area of dz.com!

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Ok, question...

Say your main canopy is fine and you've been flying it (brakes unstowed) and your cypress fires and BAM, 2 canopies out. Like some instructors, mine said to keep the brakes stowed and steer with the rear risers of the dominate canopy. Well, since you've been flying the main canopy brakes are not stowed. What do you do then? Put the main in full flight and steer with risers? Or keep on steering with the toggles?

Thanks!

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Ok, question...

Say your main canopy is fine and you've been flying it (brakes unstowed) and your cypress fires and BAM, 2 canopies out. Like some instructors, mine said to keep the brakes stowed and steer with the rear risers of the dominate canopy. Well, since you've been flying the main canopy brakes are not stowed. What do you do then? Put the main in full flight and steer with risers? Or keep on steering with the toggles?

Thanks!



Why do you believe there is a risk of your AAD firing *after* you have your main fully inflated and the toggles unstowed?
"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

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Well, it's a doubtful situation, but one of the people at my DZ had that happen to him. I'm not sure what he was doing, but it was something fast enough to make his cyress fire. It's just something that I'm curious about.

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Well, it's a doubtful situation, but one of the people at my DZ had that happen to him. I'm not sure what he was doing, but it was something fast enough to make his cyress fire. It's just something that I'm curious about.



I've heard it happening with a Student Cypres, but to fire a Expert Cypres under canopy is pretty much impossible for most people.

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Well, since you've been flying the main canopy brakes are not stowed. What do you do then? Put the main in full flight and steer with risers? Or keep on steering with the toggles?



As you said, the main toggles are already released, so I would think it better to fly the main with very small toggle input, but only letting the toggles go back up to about the stowed position. If that wasn't very stable, you might find that a bit more or less brakes on the main might improve things.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

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>But if they're side by side, what would you do if they started to down
>plane at 100 or 50 feet?

During Derek's tests, this was almost impossible to force. They always tried to return to a side-by-side. A side-by-side is a pretty stable formation for canopies to fly in.

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