Why are airlocks not popular?

[petejones45 0]

That is a false statement sir

Look out for the freefly team, Smelly Peppers. Once we get a couple years more experience we will be a force to be reckoned with in the near future! BLUES!

[SRI85 0]

thanks for all the good info. an airlock canopy will not be my next purchase. i think im likely to stick with the safire 2.

[DocPop 1]

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That is a false statement sir

Care to explain why? What is your experience when jumping air-locked canopies? I never have so I am curious.

Your answer adds little to the discussion unless you can back it up.

Thank you in advance.

"The ground does not care who you are. It will always be tougher than the human behind the controls."

~ CanuckInUSA

[petejones45 0]

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That is a false statement sir

Care to explain why? What is your experience when jumping air-locked canopies? I never have so I am curious.

Your answer adds little to the discussion unless you can back it up.

Thank you in advance.

I have 2 friends that jump samurai's/ vengeance.

Also you can do a search in the upper right hand corner and look at the gear reviews

Look out for the freefly team, Smelly Peppers. Once we get a couple years more experience we will be a force to be reckoned with in the near future! BLUES!

[DocPop 1]

I see.....

"The ground does not care who you are. It will always be tougher than the human behind the controls."

~ CanuckInUSA

[craigbey 0]

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I can count about 6-10 bad openings

+1

I have ~1100 jumps on 2 different Samurais with no chops. I have also had less than 10 openings with line twists and only a couple required any form of intervention on my part.

The Samurais that I have demo'ed and jumped all opened very consistently.

[diablopilot 2]

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JP I'll argue that with you all day. I've got almost 1000 airlock jumps and I can count about 6-10 bad openings and the worst of them was a massive line twist issue that lead to a cutaway. I've had about 4-5 hard openings but for the most part my canopies open like a Stiletto or Sabre2.

I don't have a 1000 but I have 324 jumps on 11 different air locked canopies and all but three of those canopies the regular openings were brisker than their non air locked counterparts. The 3 that opened with a soft consistent snivel were all the Paratec R.A.G.E (not the US manufactured parachute) which is a different airlock design than is commonly found in the States.

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

[freakyrat 1]

I have a 136 Samurai that opens nice and easy. It flies and lands nice. The canopies are popular in the areas known for wind and turbulence like the mid plain states.

[craigbey 0]

So, 'brisker' openings mean 'poopy' openings?

I guess it's a matter of perspective. The Samurai may not snivel as much as other canopies, but I've never had a 'hard' opening. Again, I would call it very consistent. Smooth and on heading, with only a short to moderate snivel.

There were a few sub-terminal openings on the Samurai136 that were faster than normal, but it wasn't dramatic. No broken bones or blackouts, so it's all good.

[tsalnukt 1]

I have to strongly disagree with you. All of mine have opened beautifully.

[dragon2 0]

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I have to strongly disagree with you. All of mine have opened beautifully.

My ~400 jumps on various vengeances have been mostly onheading nice slow openings too, except for a few: one brakefire on a rented vengeance 135, 1 slammer on my own vengeance 135, a dozen or so squirelly openings followed by 1 cutaway (lineover) on my own vengeance 135 that had lines that needed replacing bad at the time, and a couple squirelly openings on a borrowed vengeance 120 with very old lines. Hmm, might be a theme there

ciel bleu,
Saskia

[kingbunky 3]

since the op is a relatively new jumper, all discussions of airlocks vs cross braced are not what he was looking for.

i went from a sabre 1 190 (about 100 jumps) to a lotus 170 (~350 so far) and other than the fact that it was a little more sporty (due to the downsize) there wasn't a big change.

watching other canopies come in on days where the winds are a bit weird, you see a lot of accordion-ing out of regular canopies while my airlock just sort of bumps through it, like going over a speed bump in a parking lot.

it can be a bit of a challenge on the ground, but what i do is let it land on it's nose, then walk towards it, on the bridle. give it a couple of shakes and it's not bad.

openings i find really long (~900 ft) and kind of unpredictable. i've never had line twists, but i'm almost always off heading. usually 90 one way or the other, occasionally a 180, sometimes a complete 360. i got slammed once, not hard enough to break anything but i was done for the day. it's been very consistent in this even with different packing methods.

once it's open, it's a very nice canopy to fly. harness turns are nice, glide is amazing, tons of flare power. front riser pressure is on the high side, so if you're trying to swoop you have to go from brakes to risers pretty quick or you'll be doing a chin-up.

if it were available, my next canopy would be a samurai, either the same size or one step down. since that's not really an option, i'll probably keep my lotus.

"Hang on a sec, the young'uns are throwin' beer cans at a golf cart."
MB4252 TDS699
killing threads since 2001

[billvon 2,400]

>I have to strongly disagree with you. All of mine have opened beautifully.

To me, the argument over whether airlocked canopies open harder or softer is akin to arguing whether blue or silver canopies open harder or softer. Sure, it might indeed have an effect - but other factors are likely going to predominate.

[skyrider 0]

Nothing like going to the sorce for many answers!

http://www.bigairsportz.com/airlocks.php

[Ron 7]

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since the op is a relatively new jumper, all discussions of airlocks vs cross braced are not what he was looking for.

Not really true. He asked why airlocks are not popular, and one of the reasons is xbraced canopies are percieved to be better and offer some of the same benefits. Without xbraced canopies, airlocked canopies would still be the top of the food chain and would have increased in popularity.

Add in the marketing issues and those two issues answer the op's question.

Brian and I were talking one day about canopy design. He told me something that kind of shocked me. He told me that ROUND parachutes still offered a lot of design advances. But even a really advanced round is not going to be as nice as a decent square, so no one tries to really improve on the rounds design.

The airlocked idea never really took off since:

1. It was fixing a problem that most modern canopies do not have.

2. A more advanced design came out.

3. The exclusivity of one company owning the design , and that company having another primary focus) meant that there were not competing designers trying to make it better... If Xbraced were not being designed by several companies, there would not be as many advances.... We would only have the Icarus FX and not the velocity and VX.

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

[Calvin19 0]

Good read, but again as a lot of skydiving essays show there are one or two missing points that in my opinion should not be ignored. I am not arguing against or for airlocks here.


Heading stability. This is more important in canopy flight than most people realize. Any (asymmetric or complete) collapse situation on a glider, (be it on a parachute or paraglider) will lose exponentially more altitude in any situation if the collapse causes a heading change. if a canopy has a full frontal collapse at 300' AGL, and remains collapsed for a full second or two and re-inflates on heading, it will lose less than 100' of altitude before being a full stable glider again.
If the same canopy has the same collapse and re-inflates facing 180 degrees to original heading, it will not only lose the altitude from the loss of lift but also from requiring energy in the form of altitude to regain stable flight the opposite direction.

canopies rely on their flexibility to easily deflate and re-inflate to maintain heading stability. generally speaking the easier it is for a canopy to re-inflate after a collapse is how one would measure the heading stability in a collapse situation.

Where does this involve airlocks? well, mostly in the rigidity of the wing. It is more likely that a fully flexible glider (no airlocks) will have an asymmetric collapse, and in most cases such as parachutes it will re-inflate without heading change. With airlocks the glider is LESS likely to collapse. it would take a larger change in relative wind direction to cause a inverted-lift scenario that would cause a canopy to collapse. HOWEVER, in the event of a strong shear layer/huge turbulence that would cause a airlocked/"rigid" canopy to collapse it is more likely that the collapse would be VERY severe and cause a cravat/entanglement situation due to the gliders inability to deform.

bottom line(IMO)-
It takes a lot to collapse a normally-loaded skydiving canopy. To the point where one should not be jumping. IMHO the airlock is not a necessity in a skydiving parachute. BUT other than difficulty to control and pack on the ground, and pack volume/weight/complexity of the design, there are no real downsides to it on a skydiving canopy. I do not mind my canopy breathing a bit, and it seems to be more of an issue for larger intermediate canopies (1/1-1.5/1 load) than small advanced ones.

Of course, paragliders tried this a long time ago and abandoned it. the relatively extremely high aspect ratio of a paraglider makes collapse heading stability a HUGE issue.





NOTE- a good example of a canopy (paraglider) with BAD collapse heading stability.
http://www.youtube.com/watch?v=T24X-NBNsPM

-SPACE-

[MarkM 0]

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To me, the argument over whether airlocked canopies open harder or softer is akin to arguing whether blue or silver canopies open harder or softer. Sure, it might indeed have an effect - but other factors are likely going to predominate.

Pretty much. I've been jumping a Lotus 136 for the last several hundred jumps and any problems I've ever had with openings I'd tend to blame on a lazy packing or on a sloppy body position/deployment technique.

The biggest reason I think they didn't gain in popularity is because Brian Germain held the patent on it for skydiving canopies and his canopies(though very good) never really caught on in popularity. Other companies just marketed their product better.

And today, no one is really asking for them. There's very few designs that people really ask for. The skydiving market is kind of finicky and "follow the leader" ish when it comes to the products we buy.

[jacketsdb23 45]

So could one argue that for jumpers without the experience required to jump a heavily loaded Xbrace canopy that maybe air locks do make sense? This would leave me to believe that the major factor in these canopies not becoming popular is the marketing issue.

I don't have the numbers but I would have to believe Xbraced canopies make up a much smaller percentage of the canopy market than non-Xbrace. That pretty much takes Xbrace out of the discussion.

Losers make excuses, Winners make it happen
God is Good
Beer is Great
Swoopers are crazy.

[Ron 7]

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So could one argue that for jumpers without the experience required to jump a heavily loaded Xbrace canopy that maybe air locks do make sense?

Airlocks help, but as others have said normal canopies do not really seem to have a collapse problem. So it is a fix for a problem that does not really exist. In conditions so bad that a normal canopy is in danger to collapse, a more rigid wing *might* help but you should most likely not be jumping anyway.

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This would leave me to believe that the major factor in these canopies not becoming popular is the marketing issue.

And it is/was. Look at the PD products page.... Vengeance is not listed. The Lotus and the Sam are listed as out of production.

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I don't have the numbers but I would have to believe Xbraced canopies make up a much smaller percentage of the canopy market than non-Xbrace. That pretty much takes Xbrace out of the discussion

Except the xbraced being out there is a factor in why the airlock was not pursued. Kinda like how rounds could be designed better but people don't bother since people want squares.

And as for numbers.... I'd bet there are less airlocked than xbraced.

I used to live in Zhills.... The home of the airlocked canopy and put several jumps on several different models (eagle trim/fat top...etc). While they all performed well, they didn't perform as well as the Xbraced and the xbraced did everything the airlocked did.

In the end it was a great idea that due to the few options in design (4 total designs in the US Jedi/Lotus/Samurai/Vengeance), limited marketing, limited audience, and that they cost about the same as "better" options....it just didn't catch on.

Would it be a good idea???? Well, I always thought it would have been awesome to have it as an option for regular designs... Say PD could put out an airlocked version of the Stiletto and Sabre 2. But the added cost of the airlocks put the prices at Xbraced designs.

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

[skyrider 0]

Just lookin at the airlock design, they seem like the perfect safe parachute for areas like Perris, where dust devils are common!

[billvon 2,400]

>So could one argue that for jumpers without the experience required to
>jump a heavily loaded Xbrace canopy that maybe air locks do make sense?

A heavily loaded airlocked canopy makes no more sense than a heavily loaded crossbrace canopy if the person does not have the experience to jump a heavily loaded canopy.

Both can be jumped by less experienced jumpers at lighter loadings. Both increase stability under unusual circumstances (like strong turbulence.)

[craigbey 0]

Ron, thanks for sticking to the point regarding the marketing / distribution reasons for the lack of popularity of airlocked canopies. Good history lesson.
One more airlocked canopy that may have been in the prototype stage at some point...
http://www.bigairsportz.com/shogun.php


edited for spelling

[shah269 0]

Hu.....check out the ground launching video.
http://www.bigairsportz.com/videos.php
Wow the airlock really holds the air in. Funky!

Life through good thoughts, good words, and good deeds is necessary to ensure happiness and to keep chaos at bay.

The only thing that falls from the sky is birdshit and fools!

[Ron 7]

There was a prototype airlocked CRW canopy years ago... I think they made three of them.

Again, they sounded great in theory but the damn things were like solid boards hitting you in the legs when they docked doing rotations.

There are always so many prototypes that never get released it would amaze you.... I am sure PD has a closet full of really fun stuff that will never see the light of day. They had a ZP xbraced years before the velo, and I had heard rumors of an airlocked Stiletto.

But the demand for the xbraced was not high enough to warrant all the R&D till NZ aerosports released the EXtreme FX in Jan 1997 and then Precission started to make them here in the US. PD then had to spend the time and money so they would have a 'flagship'.

Hell, PD had the Excaliber in the 80's, so they had the idea and the ability long ago. The market didn't warrant the expense.

In fact, some if us remember the legal issues with the Precission canopies... PD had the copyright for xbraced designs, and for a time, the only xbraced flying were the NZ ones that had to be shipped in. I had Precission EXT FX 88 in 1997.... And it was amazing although it opened hard (which I am told is why PD didn't have them in ZP the 80's).

So, there is still hope that a new airlocked canopy could come out. If there is a demand... Someone will fill it.

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

[craigbey 0]

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Many feel that PD's release of the Vengeance was timed too late to capture any market and that the release was only halfheartedly done.

You posted that earlier in this thread and it reminded me about the timing of the death of the Vengeance...

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2092143#2092143
From John LeBlanc's comments...
"the Katana has taken the bulk of the narrow market between the Sabre2 and the Velocity ... it really fills this niche much better than the Vengeance ever did"


The release and marketing of the Katana was partly responsible for the demise of the Vengeance. Not that it's a bad thing. The Katanas I have jumped have been great. The 107 @ 2.1:1 kicked a$$.

The Vengeance vs Katana in the PD product line is particularly ironic to me because both of my Sams were made by PD (2004 and 2006 IIRC).