Cobalt slider coming down fast

[TaylorC 0]

I can get nice smooth openings but the slider is just whipping down pretty fast. A lot of people who see video of my canopy always flinch when they see how fast my slider comes down. It is the stock slider on a Cobalt 135. Is this normal? Is there anyway to fix it?

[diablopilot 2]

Replace the canopy.

[sarcasm]
Or you could dump somewhere between head down and full track with an 8 inch pilot chute.
[/sarcasm]

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You're not as good as you think you are. Seriously.

[TaylorC 0]

your so funny

[phoenixlpr 0]

Why do you complain if you have soft openings?
AFAK silder's purpose is controlling opening.

[davelepka 4]

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your so funny

It wasn't a joke. The factory reccomends a smaller then standard PC, and being in a slight track to get their canopies to open right.

Other companies reccomend falling straight down, and using a PC of a more standard size. Crazy stuff.

[cobaltdan 0]

Atair recommends a 24" collapsible zero p pilot. Which is becoming increasingly more standard with some rig manufacturers btw.(rws offers a pilot which by our standard of measure is 23")

The reason to use this "smaller" size is strictly for increased safety in the case of a premature deployment while freeflying.

For canopies up to 190's you do not need a pilot chute with higher drag than a 24". using larger pilots will definitively contribute to higher g shocks in the event of a deployment at free fly speeds.

as someone that fractured their neck on deployment i feel adamant that i will only fly at a speed my parachute system can safely open at with a reasonable chance of not injuring me. as i like to freefly that has to be in the 140-180mph range.

I will go jump all day and deploy in a full out 180mph stand or in a track. I know of no other manufacturer that will do the same. I am not super tough, just that my body is going to be subjected to about 6.5 g's max and the other guys more than double that.

premature deployments happen, loss of altitude awareness leading to a low pull when freeflying happen.

...

Daniel Preston <><>
atairaerodynamics.com (sport)
atairaerospace.com (military)

[AggieDave 6]

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The reason to use this "smaller" size is strictly for increased safety in the case of a premature deployment while freeflying.

That's not what you told me over the phone when I was demoing a Cobalt 170 that opened so hard that it nearly knocked me out and it wouldn't open any better. You told me that I needed a smaller PC for better openings. You also told me to double wrap small rubber bands to slow the opening down.

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

[TALONSKY 0]

As diablopilot stated if you want better opennings get a different canopy. You might try the Crossfire 2 which has consistent soft openings and incredible performance.
Kirk

[davelepka 4]

I've always been a fan of the concept that if the deployment happens in the proper sequence, that the slider is what will control the spped on the openings, not the PC or stow size or type of bands used. At least thats always been my experience.

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I will go jump all day and deploy in a full out 180mph stand or in a track

As far as that goes, doesn't the limitations of the harness or risers concern you? Rouge openings happen to all canopies from time to time. Get one doing 180, and something will break. Harness, riser, femur, spine, whatever, but something will break.

[peek 21]

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I've always been a fan of the concept that if the deployment happens in the proper sequence, that the slider is what will control the spped on the openings, not the PC or stow size or type of bands used.

That's exactly how it is supposed to work.

Unfortunately there are some canopy designs that open in a less than ideal way, so people start doing other things (and combinations of things!) as a "fix".

All the techniques you hear about get rather convoluted after a while.

[phoenixlpr 0]

I have a Cobalt135 and I have used only with a 24" ZP kill-line PC. I got only soft openings. It does matter was it clear and pull or dump from track.

[cobaltdan 0]

a slider is sized for a canopy at a particular speed to produce an acceptable delay and resulting force vs. time curve. if that canopy/slider combination is deployed at a higher speed it will open faster and the resulting g-shock higher.

it is primarily the spreading force generated from internal pressurization of the canopy that drives the slider down (not bottom skin inflation). As speeds increase the ratio of spreading force to aerodynamic force pushing the slider up does not stay the same.

canopy reefing is more than just a slider. e.g. cross porting and inlet area pay an equal role. as these govern conductance or the rate at which the canopy can inflate.

now back to the role of the pilot chute at high speed deployments. It seams unbelievable but a large pilot chute can create a higher g shock to your body at line stretch than the canopy can. the reason is that a pilot chute catches air immediately and accelerates through line extension until the system instantly reaches tension. At high speeds the effect of this is significant.

Take the case of a tandem drogue. The tandem drogue must collapse before the canopy bag leaves the container, in cases where this failed we have video and data logged load links showing 26g+ at line stretch before the parachute clears the bag !

This is difficult for many to picture because a jumper is not able to differentiate the difference in feeling from a shock on pilot chute line stretch vs. the shock on a canopy catching air. the peaks are seperated by miliseconds. With a data logger sampling force at > 1000 times a second this is easily noted. there is a distinct peak at line stretch followed by another when the canopy un-cocoons and catches air, followed by a lower extended peak through inflation to slider down.


as to bands, short bites with double stows are my preference for reducing the bag twisting on line payout but only the last locking stows have any relevance to hard/soft deployments. If the canopy catches air before line stretch you will have a hard opening. it is the job of the locking stows to protect against this.

as to limitations of risers and harness: yes this concerns me. parachutes systems that open with too much force at higher speeds are in danger of doing damage both to equipment and jumper. as to my 180mph jumps: they are as soft or softer than yours at 120... 6 g's with my body weight is well within specs of my body and equipment.

blue ones,
.

Daniel Preston <><>
atairaerodynamics.com (sport)
atairaerospace.com (military)

[TALONSKY 0]

I just have to wonder about a canopy that depends so much on pilot chute size, deployment position and stow bands in order to get good openings. I do not recall PD, Icarus or PA requiring mods like these on their current line up of canopies to get good openings.
Kirk

[phoenixlpr 0]

I just have to wonder about if a manufacturer recommends X would you experiment with Y?

For the record I have a 36" F111 kill-line PC on my Pilot150. It does not open hard either.

[TALONSKY 0]

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I just have to wonder about if a manufacturer recommends X would you experiment with Y?

My point exactly, I personally would just buy a canopy that did not require any special changes(ie.. in deployment technique , pilot chute size & stow bands) to make good openings.
Kirk

[phoenixlpr 0]

I have a list of canopies that I would not try unless I could be really bored.

You might have that kind of list too, but may be not with the same items.

[DBCOOPER 5]

I think the point Dan is trying to make is that if you get it out of the container while your head down the ones with good openings have a better chance of hurting you than one with a staged opening.

Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

[AggieDave 6]

Call me crazy, but literally every modern canopy made has a "staged" opening. You deploy, reach line stretch, snivel for a bit while you slow enough that the slider comes down the lines, then you're under a fully open canopy.

My "non-staged" XF2 consistantly took 900ft to open. The VX and Velo I've been jumping both take 700-900ft to open. Even the Sabre2s, Safire2s, Stilettos and other similar canopies I've jumped had "staged" openings. Strangely enough the only canopy I've jumped that had openings that were so consistantly hard that I could not jump it was a demo Cobalt 170 I got from Atair.

The response from Dan in a phone conversation I had with him was to purchase a PC that was much smaller then my container manufacture recommended and to double stow small rubber bands on all of my stows. Which I found odd since literally every other modern canopy I jumped had no problems with single stowing small rubber bands and the PC that my container manufacture recommends for proper extraction from the container.

Some people have had very similar experiences with Atair canopies, some people have Atair canopies that open perfect. Sure, the canopy flew decent once it was open. On a similar level of performance as a Stiletto, but the openings were so brutal that the canopy nearly knocked me out during a normal deployment. I've had some canopies have a rogue opening before, but nothing, absolutely nothing comes close to the amount of pain and force that canopy gave me on opening.

With the extreme success that Atair has had in the military market, I really wonder why Dan puts up with the pain in the ass it is to deal with the civilian sport jumper market. It seems that Atair doesn't spend any time researching or improving their sport market and the improvements that have been made over the years and the new canopies tested and released were all to serve a purpose. Research for the military industry. There's nothing wrong with that, infact, from everything I've heard and read Atair is putting out some amazing products for militaries around the globe.

Dan, as a side note, I would love to see the video I've heard about with the extreme loadings from payloads that were flown under an Onyx. That does sound very impressive.

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

[DBCOOPER 5]

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My "non-staged" XF2 consistantly took 900ft to open. The VX and Velo I've been jumping both take 700-900ft to open. Even the Sabre2s, Safire2s, Stilettos and other similar canopies I've jumped had "staged" openings. .

How do you think they would open at freeflying speeds? That was always the marketing hype for the Cobalt.I personally don't have the desire to try it intentionally.

Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

[AggieDave 6]

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How do you think they would open at freeflying speeds?

Who knows how it would perform at those speeds. I have opened while still moving very fast and the opening was fine, but its not something that I want to do with any canopy more then once or twice.

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That was always the marketing hype for the Cobalt.I personally don't have the desire to try it intentionally.

For me I'd rather jump a rig that was built to help prevent something like that from happening, then depend on my main to do that for me. Simply put, no matter how good your main is, your premature opening from a crappy container may be your reserve. Good luck with that.

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

[DBCOOPER 5]

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***For me I'd rather jump a rig that was built to help prevent something like that from happening, then depend on my main to do that for me. Simply put, no matter how good your main is, your premature opening from a crappy container may be your reserve. Good luck with that.

I agree.Just always tried to risk manage everything I can gear wise....
Thats why I'm currently jumping a Spectre for the flocking thing....

Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

[yjumpinoz 0]

I bought a container that had a Cobalt in it. I didn't shop for one just tried it out for awhile. I do like the canopy. I think it is different for me that you must fly your body throughout the "staged" opening. I understand its that way for a lot of canopies now. I am not a freeflier, but I do participate in big ways, and I like the idea of not having to take a lot of time slowing down after a very long track. All in all I am very happy with my Cobalt and its openings.

[cobaltdan 0]

“Call me crazy, but literally every modern canopy made has a "staged" opening. You deploy, reach line stretch, snivel for a bit while you slow enough that the slider comes down the lines, then you're under a fully open canopy.”


-if you jump a cobalt you will notice that the snivel stage looks a bit different from other canopies. instead of looking like a fluttering ball of fabric, you have 3 inflated center cells with an inflated and spread slider, only the outer 3 cells on each side are sniveling. the canopy hesitates in this position because of the way the planform is shaped and due to limiting the conductance of the cross-ports to slow the filling of the outer cells with air from the center. this design technique is patented. it provides for a distinct staged opening which modulates slower with increased speed, additionally it keeps the leading edge straight through deployment limiting the chance of spinning mals.

The design has been further proved in our military cobalt canopies: eg. cobalt 350’s for tethered tandem up to 1000 pounds, and cobalt 350’s for autonomous guided cargo drops of 2200 pounds , both deploying at speeds of 155kts/180mph.

You will not see another design canopy open at a 6:1 wingloading at 180mph and provide a 6 g, 8 second deployment. ;)


" hard that I could not jump it was a demo Cobalt 170 I got from Atair."

-cobalts are proven to open softer, particularly at high speeds, than other designs. there was a problem with several of our 170's. it has long ago been corrected, and unfortunately the mention beat to death on these forums. i find it interesting how much a few people continually harp on this. Why not focus on sabers, or other designs notorious for bruising? There are thousands of them out there continuously bruising and even seriously injuring people….


“The response from Dan in a phone conversation I had with him was to purchase a PC that was much smaller then my container manufacture recommended and to double stow small rubber bands on all of my stows. Which I found odd since literally every other modern canopy I jumped had no problems with single stowing small rubber bands and the PC that my container manufacture recommends for proper extraction from the container.”

-one last time: the purpose for recommending a 24” pilot is for increased safety when deploying at higher speeds. If you don’t find this valuable don’t listen. As to recommendations on rubber bands it has been my experience that using small bites and double stowing gives the lowest incidence of the bag spinning and causing line twists. Only the locking stows effect deployment.

“With the extreme success that Atair has had in the military market, I really wonder why Dan puts up with the pain in the ass it is to deal with the civilian sport jumper market. It seems that Atair doesn't spend any time researching or improving their sport market and the improvements that have been made over the years and the new canopies tested and released were all to serve a purpose. Research for the military industry. There's nothing wrong with that, infact, from everything I've heard and read Atair is putting out some amazing products for militaries around the globe. “

-at the risk of alienating anyone, the sport market is dominated by fashion and ignorance.
I would be amazed if 1 jumper in 100 could tell me the difference in construction quality between two canopies laid in front of them. A manufacturer could release a product with design flaws that kill, but sponsor enough people, give away some t-shirts and wind blades and you will have a legion of “experts” swearing it’s the best. The military on the other hand simply judges by data: the company with the best measured performing product wins, period! No fashion, no silly characters, no entitlement issues, measured performance talks, bs walks…. none of this “the red in my canopy doesn’t match the red of my jumpsuit, if you don’t give me my money back or I’ll tell everyone your canopies suck”. we continue to develop new sport designs simply because I am passionate about it, and in a sport where i have seen too many good friends get hurt and killed, I will continually do what ever I can to improve the equipment and educate the users. As to the pain in the ass’s …. I’m thick skinned.

“from everything I've heard and read Atair is putting out some amazing products for militaries around the globe. “

-thanks

Dan, as a side note, I would love to see the video I've heard about with the extreme loadings from payloads that were flown under an Onyx. That does sound very impressive.

-I will get something ready for posting in the next few weeks…

Daniel Preston <><>
atairaerodynamics.com (sport)
atairaerospace.com (military)

[AggieDave 6]

Edit: Decided to PM instead.

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

[Brains 2]

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Who knows how it would perform at those speeds.

IMGR2 does, and Robert got it on video. Ask him about it next time you see him.

Never look down on someone, unless they are going down on you.