Forums: Skydiving: Safety and Training:
Do new lines affect canopy flare?

 


Namowal  (A 63059)

Jan 30, 2012, 10:30 AM
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Do new lines affect canopy flare? Can't Post

Student question here:

Recently my landings have been getting softer and better, but the two I did yesterday were surprisingly rough. I used the same student parachute I usually use. The only difference was that it had its lines replaced since I'd used it before. Can this change or affect the flaring ability? Or did I just have a bad day?

p.s. I think it's probably a "bad day" Crazy but I'm curious...


theonlyski  (D License)

Jan 30, 2012, 10:39 AM
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Re: [Namowal] Do new lines affect canopy flare? [In reply to] Can't Post

Yup. New lines can have a huge impact on how the canopy flies compared to ragged out ones.

If the lines are new and it's landing like shit, the toggles could be set in a different spot, or you just learned how to land shitty and need to learn to land it right. Tongue


(This post was edited by theonlyski on Jan 30, 2012, 10:40 AM)


dragon2  (D 101989)

Jan 30, 2012, 10:45 AM
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Re: [Namowal] Do new lines affect canopy flare? [In reply to] Can't Post

A new lineset usually makes a of a lot of difference, yes. This does depend a bit on which types of lines are on the canopy: if it's microline (thin, bright white lines) like most non-student canopies, this difference will be way more noticable than if the lines are dacron (fatter whitish lines) like on some student canopies. This is because microlines shrink quite a lot after a couple hundred jumps, and they shrink the most on the outside. This makes the parachute not fly its best as it gets further away from its optimal shape.
Dacron is more shrink-proof than microline so there's less of this effect.

The steering line length (and hence the flare sweet spot) is likely different as well, because steering lines are the "worst" lines when it comes to shrinking. Although on a student canopy this might not make that big of a difference as the steering lines of a student canopy may be lengthened anyway.

Did you do a couple of practice flares up high? Always do that with any new-to-you canopy, which with a new lineset, this one basically IS.


pchapman  (D 1014)

Jan 30, 2012, 12:21 PM
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Re: [Namowal] Do new lines affect canopy flare? [In reply to] Can't Post

The flare with the new line set should be BETTER if anything, because the lines are likely back to the lengths the designer intended. But that's about the canopy's capability. What you actually get out of it when not used to it yet, may be better or worse, because you aren't yet used to the new feel.

One thing to learn is to feel when the brakes first 'bite' -- how far down you pull before the tail of the canopy starts to deflect, where you are just removing the slack from the brake lines. On novice canopies that may be just a couple inches, but if the distance is longer than before, it may seem that one has to flare a greater distance before anything much happens -- which is true, but not the fault of the canopy itself. As usual, talk to an instructor for details.


uberchris  (A License)

Jan 30, 2012, 1:08 PM
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Re: [pchapman] Do new lines affect canopy flare? [In reply to] Can't Post

how much does it normally cost (ballpark average) to get a canopy relined? say a stilletto 170 for example.........................


rehmwa  (D 12816)

Jan 30, 2012, 1:23 PM
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Re: [pchapman] Do new lines affect canopy flare? [In reply to] Can't Post

In reply to:
The flare with the new line set should be BETTER if anything, because the lines are likely back to the lengths the designer intended. .

just one example for line shrinkage

1 - steering lines shrink pretty faster relative to other lines
2 - if they shrink too much, then the canopy is kept from full flight
3 - less than full flight = less energy from the flare
4 - new steering line are longer allowing full flight so the flare is MUCH improved

that's just one part of the lines - let alone talking to the trim of the canopy, etc etc etc

Simplifying the OP
"Do lines affect canopy flare?" is pretty much the same as "Does the shape of a wing affect it's flight?"


Premier billvon  (D 16479)
Moderator
Jan 30, 2012, 1:29 PM
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Re: [Namowal] Do new lines affect canopy flare? [In reply to] Can't Post

>Can this change or affect the flaring ability?

Yes.

When Spectra lines age they tend to shrink. This is most noticeable on the brake likes because they see the most friction, being both the longest and the rearmost. Thus after a while the brake lines start to get shorter than their design length. Eventually they even start to pull down the edge of the canopy in full flight. This is bad since it 'flares' you a little all the time, and thus you don't have as much speed to flare at the end.

Generally it's a good idea to replace lines before that to maintain (even recover) the original performance of the canopy.

What probably happened to you:

You got used to that parachute; you were used to pulling down the toggles to your shoulders (or some other point) at 8 feet above the ground or something. Now that the lines have been replaced, that point has changed; it is likely lower. If you try to flare to exactly the same depth as you did before you won't get as much of a flare because the brake lines are now longer. If that's the problem flare deeper.

Another possibility is that the lines got so short that they were deflecting the tail of the canopy. If that's true the canopy is now flying faster. That will throw off your sight picture and tempt you to flare early since we perceive distance (partly) by how fast things are moving. If that's the problem flare later.

Best option is just get someone to watch you to see if you're doing anything different.


Premier NWFlyer  (D 29960)

Jan 30, 2012, 2:38 PM
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Re: [uberchris] Do new lines affect canopy flare? [In reply to] Can't Post

In reply to:
how much does it normally cost (ballpark average) to get a canopy relined? say a stilletto 170 for example.........................

$300ish.


JohnSherman  (D 2105)

Jan 31, 2012, 9:16 AM
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Re: [Namowal] Do new lines affect canopy flare? [In reply to] Can't Post

Get an independent rigger to check the new lines. Have an highly experienced jumper, familure with that canopy, test jump it.
The new lines could have errors in them which might affect performance. Even the factories have made mistakes.



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