closing "valves" on cells - pros/cons?

[Newbie 0]

hi all - i can't reemmebr the technical name for the valves that activate when turbulence causes the pressure inside the canopy to decrease, and forces the air out of the cells, but the they sound like a great idea to me (after having read and heard from people who have encoutered near collapsing canopies much too low for a cutaway to even be considered.)
What i want to know is why more people dont have these canopies, that effectively seal the pressure within the cells in the likelihood of turbulent air? What are the cons to having canopies that maintain pressure like this? Is there a danger the valves could close before the cells have been pressurised with air, therefore stopping it inflating?
Thanks for the help guys

[rapper4mpi 0]

What I think you are referring to are "Airlocks". How they work isn't quite right by your description. What they do is allow air in, but don't allow it to exit the canopy cell very easily. The cons of this are once you have landed the canopy dosn't collapse like a traditional canopy does, so in high winds it can be a struggle. Another con is that I've heard of canopies continuing to fly after a cut-away. The pros are the canopy is stable in turbulance and maintains a cleaner airfoil. Check out www.bigairsportz.com to learn more about them. As with anything, airlocks have their proponents and naysayers.
-Rap

[Remster 24]

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The pros are the canopy is stable in turbulance

carefull out there... this should read
the canopy is MORE stable in turb (or less suseptable to it).
another con is that they tend to pack bigger (again, due to air been forced to saty in, but also for the additional fabric)
Remster
Muff 914

[polarbear 1]

Most of the pros and cons previously listed are correct. It needs to be stated that Airlocks DO NOT make a canopy turbulence proof. All wings depend on smooth air to fly. Ram-Air wings depend on smooth air to stay inflated. Airlocks can help keep the wing inflated, but the canopy will still need "good air" to fly correctly. Don't look at airlocks as something that allows you to jump in more turbulent conditions...if you would stay on the ground with a normal canopy, stay on the ground with an airlock.
Airlock canopies can still be collapsed...they are just more resistant to it.
One thing people don't ever mention is that the airlocks help with more than just turbulence. The canopy pressure is maintained throughout the range of maneuvers a canopy sees. This adds a degree of rigidity to the canopy, similar to what cross-bracing does (although NOT the same as cross bracing). The "bracing" in the airlocked canopy is due to the internal pressure.

[cobaltdan 0]

airlocks were first tried on paragliders almost 20 years ago. i have a stack of scientific papers on the subject about 1' high. in 20 years not one single airlocked paraglider has been comercialized. this in an industry that universially adopts improvements far too small for us to care in skidiving. note that the paragliding industry has more r&d money and technology than you can imagine when compared to skydiving industry canopy design.
airlocks sound good to a laymen, but not necessarily to an aerodynamicist.
btw, i am not saying that some airlocked canopies aren't nice flying machines. just that the superior in turbulence thing is false and unproven. now to all the people than may chime in and say well my samuri is much better in turbulence than my triathon, etc... you must understand that just because my wing does not deflate does not mean i am flying, and you must compare apples to apples. i.e. the same canopy with and without airlocks (i have done this. the airlocked canopy vs the non airlocked canopy is more rigid when brakes are applied, but performance is equal. all literature i have read from the paragliding industry agrees, and many point out decreased performance)
there are several patents on airlocks for skydiving canopies. brian g is the only one comercializing designs. i think he is a great canopy designer, i am not trying to put down his work, he makes some nice wings. i just want people to understand why other canopy manufacturers are not making airlocked canopies.
sincerely,
dan

[polarbear 1]

I think I'd agree. For high-performance parachutes, I would say the other design parameters (airfoil, planform, trim, etc.) are more important than whether or not to have airlocks. A crappy wing design with airlocks is still a crappy wing design.
However, my observations (flying a Vengeance 170 and a Heatwave 170) are that the Vengeance 170 really didn't "accordian" as much and it really did seem like I got bumped around less.
I would definitely say don't buy a canopy solely based on airlocks, especially if you plan on relying on them to save you from turbulence. If it is bad enough to collapse a non-airlock, the airlock won't do much better.

[weid14 0]

wasn't there a notion that the airlocks really helped make the nose distort less, giving the canopy more rigidity -- providing a similar effect as bracing would (like I think you may have done in the nose of one of your canopies)?

[apoil 0]

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btw, i am not saying that some airlocked canopies aren't nice flying machines. just that the superior in turbulence thing is false and unproven.

"is false" ??
unproven perhaps, how do you know if it's false?
The fact that it's a competing technology to your own makes all your arguments suspect, Dan. Why don't you simply present facts without slamming the competition? It's getting pretty old.

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there are several patents on airlocks for skydiving canopies. brian g is the only one comercializing designs.

Guess you never heard of a little company called "Performance Designs"?
They are currently commercializing their own design based on brian's airlocks as you well know. Or did you just say this to try to make Brian's airlock technology sound that much more marginalized?

[cobaltdan 0]

i am not slamming anyone, read the post again.
-dan

[cobaltdan 0]

d.weid.,
yes i would have to agree with you that airlocks can add rigidity by increasing internal pressure when deflecting the brakes, but note that it is the nose, i.e. the upper curve of the airfoil from the leading edge of the topskin back to the hump of the airfoil, that is most important. current commercialized airlock designs sweep back from the leading edge of the bottom skin to seal on the top skin some distance back. the 'nose' really isn't airlocked. some prototype paraglider designs got arround this problem by placing the airlocks on the bottom skin and having a fully formed nose.

sincerely,
dan

[apoil 0]

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i am not slamming anyone, read the post again.
-dan

You are making denigrating comments about the purported benefits of a competing technology.
No matter how informed your opinion, you don't have much credibility when you yourself are trying to market something yourself.
You'd probably sell more cobalts if you didn't spend so much time talking about why other canopies are inferior.
And speaking of supposed canopy design gimmicks with questionable benefit, howzabout the Cobalt's "staged openings"?

[Zennie 0]

I fly an airlocked canopy (Jedei 136) and love it. Get great swoops and nice surfs. I've always felt like I have total control over the canopy, even on hard front riser turns. They are a bitch to gather up on windy days though.
But I like the fact that I've always felt rock solid under the thing, even on gusty days when everybody else's canopies were moving in & out like and accordian at a polka dance. People on the ground watching even notice a difference, so it's not just me.
I like the Cobalt a lot as well. I've been recommending it to people trying to move into ellipticals, because I think it provides a good mix of performance, nice openings and forgiveness.
But having flown a Brian Germain canopy, I've fallen in love with them. So my next one will prolly be a Samurai (or another Jedei).
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

[alan 1]

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and you must compare apples to apples. i.e. the same canopy with and without airlocks (i have done this. the airlocked canopy vs the non airlocked canopy is more rigid when brakes are applied, but performance is equal. all literature i have read from the paragliding industry agrees, and many point out decreased performance)

Funny you should talk about comparing apples to apples and then go on to compare the research in the paragliding industry to that of sport parachuting. That data is based on radically different wing loading, planforms, aspect ratios, cell numbers, trim angles, airfoils, etc.. I'm not slamming you, I just want people to know why other canopy manufacturers are not relying as heavily on paragliding data to question the validity of competing designs.
alan

[cobaltdan 0]

alan,
all good inventors/engineers begin with complete background research. paraglider research is most definately meaningful when applied to skydiving design.
your point/my point on apples to apples is taken and why even after reading the background research i still built an airlocked canopy. this was a little over a year ago and the airlocks were from a patent that was offered for licence to us. i got the chance to fly a cobalt with and without airlocks.
a canopy's performance is the sum of all its design variables. i view airlocks a one more design variable a designer has, using them has positive and negative traits to balance, as with most things. if you buy an airlocked canopy do so because you like the way it flies, not because you think it will save you in a turbulent condition. if such a condition is enough to collapse a modern high performance non airlocked canopy, definately it will take out the airlocked canopy as well.
sincerely,
dan

[BrianSGermain 1]

There are many things to be debated with regards to pressure containment systems, such as my "Airlock" designs. It is best, however, to look at the facts:
1) There are nearly 3000 Airlocked parachutes out there, and no one has died as a result of a parachute deflation to my knowledge.
2) Paraglider designs are irrelevant, as the wing loading, aspect ratio and average airspeed are very different from that which we experience in skydiving.
3) Those that have actually jumped airlocked canopies are the only true authorities on the subject.
4) Airlocks do exactly what they are intended to do, contain the internal pressure in the airfoil.
5) The only manufacturers to utilize the airlock technology are Big Air Sportz, Inc., and Performance Designs, Inc. Other manufacturers are welcome to look into the possibility of including airlocks as part of their parachute designs, but thus far, only two have done so. The others, thus far, seemed content to justify why it is not necessary to contain the internal pressure in their wings.
You make up your own mind. Just a thought, though:
"If airlocks aren't keeping your air in, what is?"
Brian Germain
Inventor, Patentholder
US Patent "Valve Apparatus for Ram Air Wings"

[BrianSGermain 1]

A little known fact about the modern airlock design is that they do act as crossbraces as well. The airlock panels are deliberately cut on the bias, which radiates the load across to the non-loaded rib. This is because our fabric does not stretch when loaded in line with the fabric threads (look at the boxes). This effect pulls in opposition to the force of the relative wind, and achors the non-loaded ribs near the high point of the airfoil, where the load is carried.
Sorry this has to sound so technical, but I wanted to be precise. If you have any questions about this or seek clarification, please email me: [email protected]
Brian Germain
Inventor/Patentholder
US Patent: "Valve Apparatus for Ram Air Wings"

[BrianSGermain 1]

Interesting. When we spoke at the Carolina Skysports Boogie a few weeks go, you had not compared a canopy with and without airlocks, and expressed interest in getting your hands on one of my "control canopies". Have you done some test jumping since then?
I have done this experiment hundreds of times, and have found PROFOUND differences. There is a reason why I have dedicated my life to this paradigm. Because I believe in it due to my experiences, and the experiences of thousands of customers.
Careful how you do your marketing. You could sound old-fashioned or even vindictive when commenting on other manufacturer's ways.
Brian Germain
Inventor/Patentholder
Valve Apparatus for Ram Air Wings

[ChromeBoy 0]

Welcome to the forums Brian. Your feedback from here on is greatly appreciated!

[BrianSGermain 1]

Actually, the paragliders that attempted to complete the nose didn't do so well, if you check your history. They didn't gather enough air pressure, and what's the point of that? This is why the modern Airlock is designed to gather as much air into the wing as possible, and them seal it in times of need. Notice that the panel lies parallel to the mean relative wind vector.
Believe me, I've thought this through.
Brian Germain
Big Air Sportz.com

[BrianSGermain 1]

I'll shut up now.
Brian

[kwmontreal 0]

Hi Brian,
Welcome to the forums. I was really hopeing you would come into this thread, as my tech knowledge on the issue is lacking to say the least. Thanks for bringing things back into prospective.
jump Safe
Kent

[AndyMan 7]

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I'll shut up now.

Nooooooooooooo!
Well, at least make sure ya'll come back now, ya'hear?
_Am
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[cobaltdan 0]

hey brian,
welcome to the thread !
i have read about and seen paraglider designs where the nose was fully formed. some as you said were less than sucessful. a version with a succesfull fully formed nose was designed by michael nesler who has worked for atair for about 3 years. he holds 2 european patents on canopy air locks., to his credit he designed the edel, perche, up europe, eiffel and bicla companies paragliders. i do believe that the information learned on these paraglider designs is directly applicable to skydive canopy design.
the canopies i compared was a cobalt 105 with vertical airlocks applied as per r.payne's patent they were made a little over a year ago.
differences noticed were increased rigidity of nose, but not decreased spanwise distortion,the canopy did not prove to be more efficient, i.e. did not out glide or out flare the non airlocked.
as i said i think valves are one more option in a designers bag and should be explored, again i thing you make great wings, but i do not believe valves will save you in a situation that would collapse another modern high performance canopy.

i would love to see you do any kind of a study to quantify those claims. why not simply do tests using a 'rolling test rig', i could be very interesting and fun.
sincerely,
dan
ps. you mention that airlocks cross brace the nose of the canopy. i agree that they are sewn cross bias but the function of a cross brace is simply to reduce spanwise distortion. from looking at some advertising photo's of your airlocked canopies it looks like the nonloaded ribs float up just as high as with a non airlocked 9 cell, showing that the valves are not an efective x bace in this design...
pps. dont take this conversation as adversarial, because its not. through discussion i simply hope to spark ideas for both of to make future canopies.

[polarbear 1]

Hi Brian! Welcome, we all appreciate your advice and information. Don't worry about getting technical...that is EXACTLY the type of information I like, and it is hard to come by.
I haven't been able to jump the same canopy design with and without airlocks, but I have been able to jump both a samurai and a vengeance, as well as several other non-airlocked elliptical canopies. Both the vengeance and the samurai were beautiful flying machines, in my opinion. They both felt much more solid in and out of turbulence. As for the performance, well...they both performed very nicely, but I can't say if the airlocks helped that.
Being an engineer and (almost) a rigger, I do believe that there is some sound engineering behind the airlock principle.

[amir1967 0]

Welcome to the forum
as a customer of a PD Vengeance I love your desigen and recomend it to everyone ,yes maybe it is not the highest preformance conopy out there but it keep me safe and stable when other on specter and triatlon saying look out for turb. at this or that altt.
anyway thank's again for a great invention
amir
AM67