Party pooper

[mattaman 0]

I just read a thread about a guy who had a tandem mal, spinning on a set 400 and he struggled to cut it away. Been there, but thats not my point. I hear talk of making tandem main canopies faster, smaller and more high performance. I can't tell you how pissed I get when I reflect on how many people out there have no concept that its gonna kill people, tandem customer who don't sign on for that risk. I tell you why. Load that high performance tandem canopy with 400-500lbs. Give em a spinning streamer, for those who've not had one on a tandem, they can make you shit yourself there so scary, and have them try and cut it away. Let alone with an rsl that is guarenteed to deploy the reserve in the most horrible of configurations when they come of that main tumbling. If you've never been there, you won't relate to what I am writing, and this will kill people eventually, trust me, we get by with lots of close calls in this sport. If you build one of these tiny tandem mains, you better address this, some new type of main release that cuts away easier, something. We in the field should not be your test jumpers on this stuff. matt

Those stuck in maya, seek to be seen.

[efs4ever 3]

Amen.

Russell M. Webb D 7014
Attorney at Law
713 385 5676
https://www.tdcparole.com

[Ron 7]

I agree, the problem is people don't pick gear for the worst case, they pick the gear to look cool or have fun.

I don't normally care when it is an experienced jumper, but with a TANDEM?!?!?!!? Safety first always.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[rhys 0]

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I just read a thread about a guy who had a tandem mal, spinning on a set 400 and he struggled to cut it away.

I would say that 90% of set 400s are in strong containers!

ted strong does not use the 3 ring as invented by bill booth and therefore this results in extra force on the cutaway cable. so much so that they had to change to the steel wire verion.

plenty of people have rotating malfunctions on very highly loaded canopies without any problems. do you hear of hard cutaways on well maintained vector2's, sigmas, next, PDF etc....

if you use new technology it should be used in new technology!

how about turbulance injuries from underloaded canopies?

x braced tandem canopies will be safer in those windy conditions!
you dont have to do a 270aproach because you are on a x brace you just get a much better performing wing that penetrates more and is less succeptable to collapse!!

"When the power of love overcomes the love of power, then the world will see peace." - 'Jimi' Hendrix

[freefalle 0]

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how about turbulance injuries from underloaded canopies?

x braced tandem canopies will be safer in those windy conditions!
you dont have to do a 270aproach because you are on a x brace you just get a much better performing wing that penetrates more and is less succeptable to collapse!!

how about just not taking a tandem up in winds that too high. there is a time to push limits, however, I'd prefer not to push them when I have someones wife, mother, son, daughter, father, husband or friend attached to my chest.

[skydiverek 55]

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ted strong does not use the 3 ring as invented by bill booth

How is it different?

[mattaman 0]

I don't know how many tandems you have, nor how many tandem mals, but its clear not many. Cause at the very least your reply would have been close in agreement with what I said, not only tandem hard cutaways, but also the force from the sheer wing loading causing tumbling and spinning on cutaway. reserve deployments have failed in the past due to unclear/unstable reserve deployments, causing fatalities with large canopy spinning main mals. But the issue hear is your not hearing what I said, cause it sounds like you've not been there, or been their enough. Have seventeen tandem mals, one of these a reserve. There is nothing like having a tandem customer scared shitless and not being able to get them to relax cause yourself scared shitless fighting to keep a reserve stable enough to land. Your perspective on things changes. This needs to be addressed in R and D, not the field.

Those stuck in maya, seek to be seen.

[riggerrob 558]

mattaman,

I am going to agree with some of your points, but disagree with others.

For starters, I have been doing tandems for 20 years, this month. I also have 15 tandem reserve rides, all on Strongs. Only one of those reserve openings was at terminal. Ouch! I never want to open a tandem reserve at terminal again!

I believe that 330 square foot tandem mains have a place. That place is at an ocean-side resort with consistent 15 knot winds and consistent small students (read young Japanese women).

We agree on your point about carrying fat bastards on tiny tandem mains and we agree that fashion should be the last consideration when buying tandem gear.

I am going to respectfully disagree with you about when is the best time to deploy a reserve pilot chute after cutting away. My opinion is based on a lecture given by Troy Loney at the 1993 PIA Symposium. Troy showed us extensive footage of test drops from the EOS certification process. Troy proved conclusively that the best time to deploy a reserve pilot chute is one or two seconds after cutting away. They used two different reserve pilot chutes during those drop tests. The first pilot chute had a weak spring that could launch during the first two seconds, or after 8 seconds, but was not strong enough to clear the burble during the third to fifth seconds. Needless to say, Para-Flite used the second - stronger - spring on production EOS containers.

Similarly, Bill Booth's recent tests of Skyhook deployments confirm that the best time to pull a reserve ripcord is one or two seconds after cutting away. The majority of Skyhook deployments had no reserve line-twists, no matter how badly the main was spinning before cutting away.
Cemeteries are full of people who "waited until they got stable" before pulling reserve ripcords.

[mattaman 0]

You didn't answer the question about cut away force.
I did not see the test stuff in 93, buy main canopies do not fly, open, nor perform like they did in 93. Now we're talking about smaller than 300 sq feet tandem mains.
Most of us with very small, high loaded mains do not where a rsl, there is a reason, a huge reason for this, I've seen and felt the reason bounce off my leg on a tandem reserve with an rsl. The reason is obvious for those willing to acknowledge it. I wonder why most people are afraid to look at this and acknowledge this. The reason is cause its a pink elephant.
If you put high loadings on smaller tandem mains, give em a spinning, fast mal, your gonna have some fatalities from reserve entanglements, and problems or fatalities from hard cutaways, its that way in the sport.
PS, the people who died trying to get stable to deploy the reserve did so cause they had to fight their ass off to cut it away for so long cause it was hard and they were spinning fast and were flung off it, thats exactly the situation I'm talking about not putting tandems in by with small tiny canopies.
this question needs to be fixed before it hits the showroom floor, tandems are people who've no clue

Those stuck in maya, seek to be seen.

[douwanto 22]

I jump the A2 350 and cant spin it up. I guess I could with some very very agressive canopy flying. My point is I dont think a TI should be able to spin a tandem canopy up with normal input or even being a little agressive. The 400 comes around rather easy and limits your options in reflex situations. just my 2 cents. I fly my A2 very hard and enjoy sharing that part of our sport with those passengers who want too.

Chris

Uncle/GrandPapa Whit
Unico Rodriguez # 245
Muff Brother # 2421

[mattaman 0]

This is amazing, you have no clue what I'm talking about. A streamering spinning mal. I take it you've never had one?
Listen, just imagine that set 400 coming out of the bag and starting to rotate right away, spinning the risers up, getting the tension on the 3 ring real tight, now imagine this with 500 lbs on it, now take that set 400 and shrink it by about 120 square feet, this is what we're discussing.
The cutaway force will be crazy, and so may the rsl reserve deployment when they come off that spinning grim reaper

Those stuck in maya, seek to be seen.

[Liemberg 0]

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I jump the A2 350 and cant spin it up.I guess I could with some very very agressive canopy flying. My point is I dont think a TI should be able to spin a tandem canopy up with normal input or even being a little agressive.

I love my HOP330 just as much but I'm reluctant to take it up with big guys / long legs after an "interesting" experience with a passenger from that category who induced a turn on opening.

Mattaman has a point.(though I managed to get away with it and didn't experience a realy hard pull on the cutaway...)

Its not about steering the ship in calm weather - its about preserving it in a storm with cattle at large in the hold.

"Whoever in discussion adduces authority uses not intellect but memory." - Leonardo da Vinci
A thousand words...

[AggieDave 6]

After 2 WILD spinning mals over the past couple of years, one was a bad lineover on a EZ-384 and the other was tension knots involving the right outside D/C lines at the cascade and the steering line's cascade on a Sigma 370. Even on those canopies I felt like I was on my sport canopy. On my back and spinning FAST and HARD. The chop was a bit harder, the view of the freebag flying off my shoulder instead of behind me. Followed by linetwists on the reserve. It was a FAST reserve opening, for a tandem, as well. Enough force from the spin that we were launched into the reserve. No delay like when you chop from something that is flying fairly stable but unlandable.

A large majority of my tandems are at or near 500lbs total weight simply due to my size. I couldn't imagine dealing with one of those mals under a 300-ish sq ft X-braced tandem main. Is that the future of tandems? Well, maybe...maybe there's some other technology out there that hasn't been invented yet that will actually be the future. Will there be injuries and/or fatalities due to canopies like that being used in every day applications instead of special use applications? Yeah, I think so, unfortunately. I can't change that, BUT I can make sure me and my student aren't one of them.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[mattaman 0]

Glad your an instructor Dave, the students are safer with that maturity, matt

Those stuck in maya, seek to be seen.

[teason 0]

I think the small Tandem canopy market is not for higher performance landings.

The smaller canopies allow smaller TMs a better flare and a loading that penetrates into the wind the way a tandem should.

I have several sets of gear at my DZ and I have 4 different types of mains. Quite often, I'm the only TM so I look at my Tandems and pick the rig that is best suited to thier weight and the wind conditions.(I have canopies for bigboys and canopies for small girls in winds)

You are absolutely righ that the higher a loading = a higher performance mal but that doesn't mean that a 5'2" female TM weighing 120lbs taking a 5' 2" 120lbs student should be jumping a 500 square foot canopy (Jumped one, that's alot of fabric to pull).

The smaller Tandem canopies are no different than using different sizes of main for FJs and AFF students. You don't need to put 290 Mantas on the little ones.

Perhaps lowering the max recommended weight limits on the smaller canopies would be a solution.

I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

[cpoxon 0]

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just imagine that set 400 coming out of the bag and starting to rotate right away, spinning the risers up, getting the tension on the 3 ring real tight, now imagine this with 500 lbs on it, now take that set 400 and shrink it by about 120 square feet, this is what we're discussing.
The cutaway force will be crazy

Whilst I realise this completely contradicts the point you are trying to make, are there any manufacturers of tandem equipment out there who are putting hard housings in their risers?

Playing devil's advocate, where would you draw the line? Would you like to see a maximum wingloading for tandem students? We have it in the UK for static-line and AFF students, so why not tandems? Something along the lines of a maximum of a Class 3 (Mid Range) rating (1-1.25 lb/sq ft) according to Icarus? I'm 168 lbs. My dropzone has a 224 lb limit for tandem students. I regularly jump a Hop 330. Assuming 20lb for gear that gives me a wing loading of 1.25 which is about the same as 500 lbs under a 400. There are a lot smaller instructors out there too (as well as a lot larger ones!)

Skydiving Fatalities - Cease not to learn 'til thou cease to live

[boxingrrl 0]

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Assuming 20 lbs for gear

I want to jump your tandem rig! Our Vectors weigh in at 50-55lbs, and then there's the student harness...

[cpoxon 0]

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Assuming 20 lbs for gear

I want to jump your tandem rig! Our Vectors weigh in at 50-55lbs, and then there's the student harness...

Yeah, I was being a bit generous to achieve the 1.25 loading. Assuming 55 lbs takes it up to 1.35. Mind you, don't Jumpshack make a 38lb tandem set up?

Skydiving Fatalities - Cease not to learn 'til thou cease to live

[teason 0]

You bet, my Racer Tandem is about 38 - 40 lbs (my scale sucks) It's also abou the size of a large student rig.

Makes it possible to climb out of our narrow body 182 with a pilot whose 6'4" and all legs with a 6'10" passenger and yes, that's with a 400 square foot main.

I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

[riggerrob 558]

PS, the people who died trying to get stable to deploy the reserve did so cause they had to fight their ass off to cut it away for so long cause it was hard and they were spinning fast and were flung off it,

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

If 3-Ring handles pull forces exceed 22 pounds, then TSO C23D is void.
Conscientious tandem manufacturers do everything they can to keep pull forces within reason: hard inserts in risers, special stainless steel rings, different types of cables, even 4-Ring releases.

[mattaman 0]

You said the key word here, conscience. Some instructors in the sport take the Eric Cartman approach to safety. Its not there top priority. Why, cause they don't approach it that way, they can't see past their needs. You here them in their posts not even acknowledging that a tandem passenger doesn't sign on to meet the instructors needs, they sign on to learn to experience what we all want. Our job, get them through this, as safe as we can. Tandems are inherintly dangerous, just within themselves. If you don't think so, do them for a long time, you'll soon see just how many things can go wrong, and do on occassion. If your gonna make smaller canopies, better deal with the cutaway question, its not been dealt with on Strongs well enough, and 22lbs on a cutaway with a large load, and small wing is going to be exceeded, guarenteed.

Those stuck in maya, seek to be seen.

[teason 0]

A large factor in the loading of the rings is the side loading caused by the risers twising together. if you take a 3 ring and twist is you'll see a loading on the loop.

That means you don't have to have an extremely aggressive spin to catastrophically increase the pull force required to move the cable, more of a combination of a twist and a spin.

The force on the cable and the force required to move the cable are not equal although there is a relationship. Other factors include but are not limited to; properties of the cable(non lubed lolon, teflon etc.)and the point of kink and cable suck through.

An interesting note is that a cable that would require more pull force is less likely to kink and get sucked through the gromment. For example, in tests, lubed lolon sucks through at about 70lbs while nonlubed sucks through at about 90lbs. I haven't tested strong cutaway cables yet, maybe worthwhile.

There is no perfect system and this is the flaw in the three ring. The demands of a doing a Tandem with 180lbs of flailing terror strapped to you just makes it worse.

I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

[Liemberg 0]

(Just replying to the last post in the thread)
I cannot find back where I got it on their website (http://www.basik.fr/) but I got a (pdf)manual from the European "Advance" tandem.
Interesting there is that it has a FOUR ring system in stead of a 3 ring which may have to do with both reducing pull force and allowing for stronger risers (dont know, just guessing...). Also they have a different housing for the cut-away cable.
I'll try to point Jerome Bunker (who is also on the forums now and then) towards this discussion here - maybe he has something to add...
(Like "why the four rings in stead of three / why the different end on the cable housing")

Maybe we can have our cake and eat it too...

"Whoever in discussion adduces authority uses not intellect but memory." - Leonardo da Vinci
A thousand words...

[jheadley 0]

Here's a thread about 4 ring releases we had about a month ago

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2422383;search_string=four%20ring%20release;#2422383

The issue I brought up was not addressed though. Sparky gave a table listing various loadings on a 3 ring release and how much force it took to release it. Even under a very heavy load, the force shouldn't be that bad. With his table, with the extreme example of a 2000 pound load (I don't know a lot of physics but I believe that'd be equivalent to a 500 pound tandem pair spinning at 4 G's) with tandem sized 3 rings, it would only give 11 pounds of pull force, half the max pull force allowed for a reserve.

That's 2000 pounds one a single 3 ring relase though. If 2000 pounds were distributed over 2 of them, like on a parachute, I don't know if that changes it. I know in physics a lot of things don't scale proportionally.

[Laszloimage 0]

I think the "Sky Hook" from Relative Workshop makes a big difference in the spinning mal. (Of course things like that don't exist on the Strong).
And the most important thing is DON"T pack one!
I have over 2000 tm's and no chop so far. I pack for my self when I'm allowed... (Some DZ's they don't let you). Every single close call on the TM came from the high school kids kind of packers.