New Dutch Canopy Regulation, Opinions?

[Push 0]

Actually, there are some people I heard about that weigh that much and jump. How does a 20 minute canopy ride sound? The beauty of the bell curve is that it never reaches zero.

I'm just concerned that, while this makes the progression safer for the majority at the bump, it may make it more dangerous for the fringes of the curve. As it stands, the risk of skydiving is already marginal. These regulations may just be moving the risk from being evenly distributed across everyone to nothing for the "normal" people and more for the far ends of the curve. That just doesn't sound right

-- Toggle Whippin' Yahoo
Skydiving is easy. All you have to do is relax while plummetting at 120 mph from 10,000' with nothing but some nylon and webbing to save you.

[sandi 0]

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With a 85Lbs person I would question his/her medical examination....

Wow, so according to you, small people either don't exist or there is something physically wrong with them.

I'll give you an example. My sister is 5'0" tall and weighs 90 lbs. She's not a skydiver but she certainly could be if she chose to and there is a good chance she will in the future. Considering the fact that she runs marathons I'd say she's in in better physical condition than most skydivers.

There are very light people out there who are perfectly healthy, contrary to your belief.

[USPA 0]

uhm... please mind the smiles....

The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die...

[skybytch 259]

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uhm... please mind the smiles....

Might be a good idea to limit the sarcasm to the Talkback forum... This is a topical forum; most people expect to read serious replies here.

[USPA 0]

Ok on a serious note then:

(replying on the earlier post)

If 1 or 2 people in The Netherlands have to stay on the ground more often because of wind, and by doing that we can save the lot, I chose that option...

The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die...

[sandi 0]

I guess I'm just tired of being part of the small minority that doesn't seem to matter to the people who make regulations like this.

This may be a good guideline for 80% of skydivers. But you still need to think about the 10% that are very light and also the 10% that are very heavy. A heavy jumper may have to stay on a 210 until they get to 500 jumps.

Why not take those people into consideration by adding a weight category. Lower the minimum canopy size slightly for people who are under a specified weight. Lower the max wingloading slightly for people over a specified weight.

I would be a category 3 jumper, on a category 3 canopy at a category 3 wingloading. Sounds good until you throw in the min canopy 150.

[SunWukong 0]

It seems to me like lighter jumpers would be better served by having multiple sets of wingloading requirements rather than a flat-out limit on canopy size.

For instance, amend Cat II to allow no more than a 1.1 wingloading on canopies of 170 sq. ft or greater, and no more than a .9 wingloading on canopies of less than 170 sq. ft.

[skybytch 259]

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Lower the minimum canopy size slightly for people who are under a specified weight.

Have you read this? Should give you some insight as to why 1.0 on a 120 is far different than 1.0 on a 190 - and therefore why a 100 pound jumper might be a whole lot safer at .8 than at 1.1.

Personally, I don't see a problem with a .8 wingloading - yes, even for someone with 500 jumps.

[relyon 0]

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Yeah, well, all that is moot, as I'm not even allowed to jump a Lightning 126 anywhere in the near future categories or no...

I've got quite a few jumps Lightning 126s in the 1.5-1.6 range. While I understand your frustration, I'm afraid I agree with the guideline regarding Lightnings specifically and the rest in general. It is not a sub-100 jump canopy at any wing loading.

Ask Henny Wiggers or Kees Topps about landing highly loaded (2+) 7-cell CRW canopies (mention Imatra).

Bob

[relyon 0]

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1) a 120 sq feet flies ALOT faster at 1.2 then a 170 sq feet at 1.2.

I absolutely agree with this statement.

This is incorrect. The freestream velocity (V-infinity) of both canopies will be the same. The smaller canopy will be more responsive (which may be what you are referring to), but they'll both fly at the same speed. The smaller canopy will be less efficient than the larger due to scaling effects.

Bob

[Hooknswoop 19]

http://www.performancedesigns.com/docs/wingload.pdf

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1) a 120 sq feet flies ALOT faster at 1.2 then a 170 sq feet at 1.2.

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I absolutely agree with this statement.

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This is incorrect. The freestream velocity (V-infinity) of both canopies will be the same. The smaller canopy will be more responsive (which may be what you are referring to), but they'll both fly at the same speed. The smaller canopy will be less efficient than the larger due to scaling effects.

It is true, a 120 at 1:1 will be faster than a 190 at 1:1

Hook

[Push 0]

From the document you linked to:

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II. General Concepts that are frequently misunderstood

A. Different canopy models of the same size may perform differently, but they will fly approximately the same speed. Wing loading is the biggest determinant of speed. A Stiletto 190 is not really faster than a Sabre 190, or even a PD 190! Other aspects of performance will be different, however. (Turn rate, glide angle, etc.) These differences may influence a person’s impression of speed.
B. A person evaluates a canopy’s speed according to their individual frame of reference, which has been created through their own, unique experiences.
Example: Jumper A and jumper B weigh the same, jump the same canopy, and have the same number of jumps. They may have completely opposite opinions of the speed and handling of their canopies. Why? Different frames of reference! The canopy may be the smallest one jumper A has flown. He may have chosen it to get more speed, quicker turns and hotter landings, and might feel that it’s a handful! Yet jumper B may have moved up one or two sizes to this canopy, to create more forgiving handling and easier landings than he had previously.

So the difference is not in the airspeed, but in the responsiveness. This is not surprising, since responsiveness really depends on the shape of the airfoil, ie, the way it's deflecting the air.

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A. Lighter jumpers face a greater challenge than heavier jumpers do when jumping typical first - jump student gear, due to very slow flight and sluggish controls.

1. Lighter students usually start at lighter wing loadings and very slow flight speed, compared to larger students, because they often use the same canopy.
2. The instructors are less likely to give a lighter student the attention to canopy control they deserve. It’s easier for an instructor to notice a slight problem with the larger student’s performance, and they are more likely to correct it. The instructor is likely to be less concerned about the lighter student, because the canopy is so slow that the landing is likely to be soft, even with poor technique, and the possibility of injury is remote.

Sounds like a claim that the person on the very low wingloading is not learning anything under that parachute. Seems to me that this implies, paradoxically, that there is such a thing as too small a wingloading, that is, a wingloading so small that the parachute does not need you to fly anymore.

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B. Lighter student graduates face considerably different challenges when they start downsizing.

1. Lighter students are normally encouraged to be more aggressive when down sizing, making much larger changes in wing loading than their heavier counterparts. Though the resulting speed may be similar or even less than that of a heavier novice, they’ve experienced a much bigger change in speed compared to what they started with.
2. Due to the fact that the smaller jumper will likely be transitioning to a smaller canopy than the larger jumper will, they’ll get quicker responsiveness from that canopy. Again, this is true even though they’re wing loading is probably lower.

So they need to progress differently from the average sized jumper. I read that as a claim that a large safety benefit is provided by helping that jumper downsize safely.

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V. Conclusions: As you can see, the answers to the questions in the quiz are all false. We must be very careful when discussing canopies with those who are downsizing. Do not recommend specific canopies to individuals without spending some time to learn about the jumper’s particular frame of reference. Assist others in making small changes in canopy size from what they are used to, and only if they’re ready to deal with the higher speeds and more agile handling.

What happens in this progression is that the 85lbs person is kept at < 1.0 wingloading and moderately large canopies until they reach 1000 jumps, and are then allowed to do whatever they want. While there is obvious merit in making their progressions gradual, seems to me that this is accomplishing the opposite. According to this article this kind of progression can prove disastrous.

-- Toggle Whippin' Yahoo
Skydiving is easy. All you have to do is relax while plummetting at 120 mph from 10,000' with nothing but some nylon and webbing to save you.

[sandi 0]

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Have you read this? Should give you some insight as to why 1.0 on a 120 is far different than 1.0 on a 190

Yes, I have read that and I've referred to it previously in the forums. I also mentioned earlier in this thread that lighter people will get more responsiveness from a canopy at a lower wing loading. Which is why I didn't say to disregard minimum canopy size requirement. I certainly wouldn't want a 100 lb person to have a 1.3 loading at 200 jumps. I'm saying why not let the smaller person go down to a 135 so they can be progressing with their canopy skills.

I'm just going by what I've experienced as a lighter jumper. I have flown a 120 at 1.1 and yes I know it's turns faster than larger canopies at the same windloading but it's also not as fast or responsive as people here are implying. It's not like a 120 loaded at 1.5.

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and therefore why a 100 pound jumper might be a whole lot safer at .8 than at 1.1.

Personally, I don't see a problem with a .8 wingloading - yes, even for someone with 500 jumps.

Okay then, but don't just limit it to small jumpers. Make everyone have have a low wingloaing.

[relyon 0]

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It is true, a 120 at 1:1 will be faster than a 190 at 1:1

Define "faster". Scaling effects on canopies cause minor (on the order of a few feet per second) differences at equal wingloading due to proportionately minor variations in lift and drag coeffiecients. I don't consider than "ALOT". If the difference were large, a jumper under a Lightning 193 wouldn't have a prayer trying to catch me under my equally loaded 126 to dock (I can assure you that's not the case). Any introductory aerodynamic text has all the derivations.

Bob

[Hooknswoop 19]

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Define "faster".

Higher top speed, more altitude lost in a 360, faster turns.

Hook

[relyon 0]

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Higher top speed, more altitude lost in a 360, faster turns.

These are all very dependent on flying style because the flight is accellerated. I believe I know what you are referring to and that is what I meant by saying the smaller canopy would be more responsive.

Bob

[billvon 2,400]

>Brian's system is a great system and we're actually implementing it
> at my DZ for students/low time jumpers.

It's a good system, but please realize that 95% of the jumpers out there think they should be excluded from the system because they are unusually skilled; they usually find a way to exclude themselves. So unless we're willing to make it mandatory (and that would include you) I wouldn't place much hope in such a system.

[AggieDave 6]

The main point is that it is going to be strictly inforced on our rental gear/student gear. Especially since we have some transition type canopies for some of our more advanced gear renters (Sabre2s), that could be loaded reasonibly well by a heavier jumper.

As for individual jumpers, that's similar to what it is at almost every DZ. Up to the descretion of the S&TA/DZO/DZ Staff. If some jumper shows up with a VX 14 or something crazy and doesn't have many jumps, then a long talk followed probably by a call to his/her previous DZ will be in order. Make sense?

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

[billvon 2,400]

> it is going to be strictly inforced on our rental gear/student gear.

Have you had a problem with injuries due to overloading on rental gear?

>Up to the descretion of the S&TA/DZO/DZ Staff. If some jumper
> shows up with a VX 14 or something crazy and doesn't have many
> jumps, then a long talk followed probably by a call to his/her >previous DZ will be in order. Make sense?

Sorry, I thought we were talking about a new system.

[kmcguffee 0]

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There are licenses for freefall, why not canopy?

To me that makes a lot of sense. If we are really serious about reducing the number of deaths under canopy then something like that may work.

"Any fool can criticize, condemn and complain and most fools do." Ben Franklin

[AggieDave 6]

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> it is going to be strictly inforced on our rental gear/student gear.

Have you had a problem with injuries due to overloading on rental gear?

No, but we don't ever want to have that problem, so we're starting now. (which is early in the DZ game, we've only been open 1 year this month).

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

[dragon2 0]

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Yeah, well, all that is moot, as I'm not even allowed to jump a Lightning 126 anywhere in the near future categories or no...

I've got quite a few jumps Lightning 126s in the 1.5-1.6 range. While I understand your frustration, I'm afraid I agree with the guideline regarding Lightnings specifically and the rest in general. It is not a sub-100 jump canopy at any wing loading.

Ask Henny Wiggers or Kees Topps about landing highly loaded (2+) 7-cell CRW canopies (mention Imatra).

Bob

I did ask Henny, he said 100 jumps was kinda much!

We aren't talking about loading them that high tho! Team Teuge etc can do what they want of course, but I don't think there are many jumpers who can land a Lightning/Tri loaded that much with the brakes set short as well.

I started doing CREW at just over 100 jumps, I jumped a 1:1 loaded Lightning 143. Never saw the problem some people have landing it! No biggie. But then, I've jumped mostly 7 cells. I can imagine some problems/adjustments if you usually jump a HP canopy and have never jumped a 7 cell. A Lightning has so little forward speed. But then, your reserve would land kinda like that, no?

ciel bleu,
Saskia

[skybytch 259]

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So the difference is not in the airspeed, but in the responsiveness.

The difference between a 120 loaded at 1.0 and a 190 loaded at 1.0 is the responsiveness, yes. Responsiveness kills and injures as often (or more often?) than pure speed does.

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Sounds like a claim that the person on the very low wingloading is not learning anything under that parachute. Seems to me that this implies, paradoxically, that there is such a thing as too small a wingloading, that is, a wingloading so small that the parachute does not need you to fly anymore.

Sounds to me more like a wake-up call to instructors.

I've jumped a 421 sq ft tandem canopy solo - at about a .4 wingloading. Still required plenty of pilot input.

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I read that as a claim that a large safety benefit is provided by helping that jumper downsize safely

Every jumper should have help in downsizing safely.

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According to this article this kind of progression can prove disastrous.

I see your point. That's why I'd be in favor of something like this as a USPA produced guideline in the US - but not as a part of the BSR's. Even though I've been baggin' on sandi in this thread (don't hate me sandi! Not yet anyway! ), there will always be exceptions to the rules - people who don't fit the "norm." imho there needs to be room in the "rules" to accomodate them.

[relyon 0]

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I did ask Henny, he said 100 jumps was kinda much!

Well, I respect Henny's opinion quite a bit (he's got multi-thousands of jumps more than I) and though I won't argue the point, I still won't recommend a Lightning at under 100 jumps. It's just a difference of opinion, but that might mean the difference between a stand up, a PLF, or breaking something. I've never broken anything yet and don't care to find out what it's like now.

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I started doing CREW at just over 100 jumps, I jumped a 1:1 loaded Lightning 143. Never saw the problem some people have landing it! No biggie. But then, I've jumped mostly 7 cells. I can imagine some problems/adjustments if you usually jump a HP canopy and have never jumped a 7 cell. A Lightning has so little forward speed. But then, your reserve would land kinda like that, no?

CRW with just over 100 jumps? Very good. Welcome to the "dark" side!

Standard line lengths and low loadings are going to produce better landing characteristics in most any canopy. Shortlining (8') and higher loading (1.4+) a Lightning changes the landing characteristics and flight speed considerably. Heavily loaded Triathlons in particular are very different from lightly loaded ones. Aside from 2 jumps on a Sabre 150, I've not jumped anything but 7-cells. As far as the reserve ride goes, I'm very happy my Tempo 170 is smooth flying and relatively unresponsive. By the time I'm see it I'm usually not in the mood for any more surprises.

Bob

PS - Please say hello to Henny & Kees for me when you see them. I'm going to be in Amsterdam for 8 days in late July/early August. Perhaps we can make a few jumps?

[nacmacfeegle 0]

"That's why I'd be in favor of something like this as a USPA produced guideline in the US"

This is what I said way up the thread, it might work as guidance to be used by S&TAs, instructors, CCIs etc. Regulation is likely to be unpopular.

It also struck me last night, that this could form the basis of a screening tool that could be deployed by responsible gear retailers and dealers. I've yet to dream up a scheme to protect newbies from irresponsible dealers.
This way the retailer can rest easy that they have taken reasonable steps to assess a jumpers suitability by applying a recognised 'standard' or guidance.

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He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me. Thomas Jefferson