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ramon

New HMA lines snapped !!!!!

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I witnessed this...No FUD!!!
A jumper on the 124 way Texas state record atempt was borrowing a new XAOS 135 (a big one he was a big boy maybe 250 exit).
I saw the most violent spinning mal I have ever seen (actually aout 80 people saw it and were screaming cutaway...the delay in chopping was was due to the fact that the jumper was actually trying to figure out why he was spinning.)
Anyway. Once he was on the ground and the exitement and debrief from 124 way was over he looked at the canopy.
Results: 4 "A" lines on one side snapped (the middle of the line not the attachment point). One brake line also snapped.
No shit... no FUD...There may be more facts and circumstances...but....
peace
Ramon
"wee girls on a skydive road trip on big bikes...... yikes, dykes and bikes kinda thing...... ", David McKelvie

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According to PA, the maximum weight specs for a Xaos-21 135 is 259 lbs. So assuming your guesstimate is correct he was right at the limits of the canopy (which PA says are absolute limits on their website).
Not saying that's what caused it, but that was the first question that popped into my mind.
"Zero Tolerance: the politically correct term for zero thought, zero common sense."

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Zen,
these are canopies designed with very high end performance in mind (think loading of 2.5 )... while I am sure PA has to set limits on the loading (probably for leagal reson if nothing else), I dont think a absolute max wingload of 1.9 is very representative of what these canopies are loaded at in real life...
Remster
Muff 914

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Uneven loading of the lines can cause some weird things to happen to a canopy. I saw a Nitron get shreded 2 weekends ago and it was only on one side of the canopy. The jumper had apperently loaded that side more then the other during the opening and that much stress was enough to blow seams out and rip the ZP fabric like it was a wet napkin. Being symetrical in the harness takes on new meaning with new materails that have a 0% strech rate unlike some of the older materials and their 3% strech rate possible.
Drop the tube...DROP the tube...

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Point is they are supposed to be tested at much..much greater weights..it is called "over design".
If they say 5 lines snapped because he was close to max suspended weight, I would never buy a canopy from that company...especially a reserve. If they say..oh, there was a bad HMA lot or...dings on the grommet weakened the lines, or the lines were exposed to too much UV and were brittle that is different.
VX has a continuous 2.4 wingloading max (9 cell line set).
FX has continuous 2.2 wingloading max (7 cell line set). Obviously you know Hoop is like 2.7,Chris miller is like 2.9 and Derek jumps regulalrly at 3.1. We all know Luigi Cani jumped it at 3.somthing and everyone knows Slaton has 'unofficially' jumped the 46 with weights on rumored to be close to 4. something
and on a lighter note Big Jessie is loading his xaos 89 at like 2.7 or 2.8..no probs
and of course this is a different situation. Xaos wing loading is 2.4 max till the canopy is 108 sized and then the limts go down so obviously they are putting a definite weight cap on a 7 cell continuous line set.
I have still refrained from any FUD rumors from Europe ;)
ramon
"wee girls on a skydive road trip on big bikes...... yikes, dykes and bikes kinda thing...... ", David McKelvie

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"The jumper had apperently loaded that side more then the other during the opening and that much stress was enough to blow seams out and rip the ZP fabric like it was a wet napkin."
Did Precision tell you that? Did an experienced master rigger tell you that, or is that someones opinion at your DZ? I just want that statement to be qualified.
If Precision told you that then we should all buy a Cobalt because they test them in every opening orientation loaded up at different speeds and they market that.;)
ramon
P.S. one of my canopies is a vengeance with vectran lines, I dump in tracks and all sorts of silly postions..no problem
"wee girls on a skydive road trip on big bikes...... yikes, dykes and bikes kinda thing...... ", David McKelvie

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Yes...
I hope the guy that owns the canopy sends it to precision for inspection because there are a lot of rumors about the lines and if it was something very explainable it would do a lot to discredit/substantiate the rumors.
;)
ramon
"wee girls on a skydive road trip on big bikes...... yikes, dykes and bikes kinda thing...... ", David McKelvie

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yes that was it.
I didn't know about the hole in the slider....that could explain a lot depending on how big it is..
r
"wee girls on a skydive road trip on big bikes...... yikes, dykes and bikes kinda thing...... ", David McKelvie

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Hey Clay, this was a frightening one, no two ways about it.
In the middle of 130 other canopies, spinning very wildly is not my idea of a good day out.
I'm concerned about this as well, I asked a Q here a long time ago re the HMA lines, and a rumour that they were 'banned' from use in Europe on parapent (soaring) canopies.
I never got an answer either confirming or denying this......
I've had broken lines on a PA monarch (4 or 5 lines snapped, and several cells 'blown out'), after about ten days of consistently hard openings, and its not funny.
Cya
D
GR# 37
"I don't believe that kindness is a weakness"

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We figured that out because all the damage was on the left side of the canopy only. The riggers inspecting kept finding more damage the longer we looked at it, first it was just a big cell blow out and a rip on the bottom of cell 3 going from the edge of cell 2 to cell 4 between the steering and D lines. Then the seam between 4 and 5 was ripped. Then we found line attachment points ripped off the canopy, all on the left side of the canopy. Then we found cross ports ripped open. At that point I walked away and left the riggers to look at it more, but with all the damage on only one side of the canopy, they talked about it being loaded heavier on that side of the canopy then the other. Not one HMA line was broke on the damaged canopy I looked at though.
Drop the tube...DROP the tube...

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Quote

I've had broken lines on a PA monarch (4 or 5 lines snapped, and several cells 'blown out'), after about ten days of consistently hard openings, and its not funny.


In my short time in this sport I have seen broken lines and incredibly hard openings on MOST manufacturers canopies. I have seen them on several PD's (One a Stilletto which really puzzled me. Opened so hard it knocked the jumper unconcious) I have seen it on an Alpha with several broken A & B lines. Unfortunately, the guy tried to land it. Didn't work out too good. I had the hardest opening to date on an Aeroglide 235. I was hurtin!!! I happen to know that that one was crappy packing on my part. So, if I was going to stop buying from manufacturers because I saw a hard opening or broken lines......I guess I'll have to go out to the garage and build my own canopy...:D
A cross braced canopy is something like a Formula one race car and you don't get 200,000 miles out of a Formula one car. Thats all I'm saying.
"Here I come to save the BOOBIES!"

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There are no design/testing requirements for main canopies.
If the damage is all on one side of the canopy, it is a good indication it was loaded unevenly in deployment. It is not hard to do...one shoulder low and you get 80% opening load on one side, 20% on the other. It may just be for a split second but that is all it takes to snap lines.
Of course HMA will snap before Vectran...Vectran comes in 750 lb and 1000 lb strengths, HMA is 550 lb.
When you get to extremely small HP canopies, the recommended maximums are a function of the aerodynamics of the parachute AND the material properties. As you make bigger sizes of these canopies, the aerodynamic limit goes up, but the material limit doesn't change much. Get to a BIG super HP (ie Xaos 135) and the aerodynamic limit is way over the material limit...thus a maximum wingloading of 1.9.
Having said all that, I won't buy an HMA-equipped canopy...yet. I always let these things go around in the public for a couple of years. Regardless of how well a company tests a canopy, new problems always come up when you put one in the hands of the average idiot who are NOT engineers, aerodynamicisits, canopy designers, riggers, etc. Precision isn't the only company I apply this ideology to...I do the same with all of them.

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"Of course HMA will snap before Vectran...Vectran comes in 750 lb and 1000 lb strengths, HMA is 550 lb."
Vectran comes in 500 lb (actually something like 528lb) and is used for A-B-C-D lines on a lot of canopies and 750/1000 for lower control lines. My VX is completely lined w/ 500 (528ish) Vectran, including the steering lines. I have replaced the A and B lines once, the steering lines 4 times, and the C-D lines 0 times. The canopy has 420 jumps on it. I replace the lines before they break, especially the steering lines.
It is my understanding that HMA doesn't handle being sewn very well. So fingertrapping B and D lines into the A and C lines weakens the line too much. I think that is the reason for continious lines on HMA lined canopies. I don't have any hard facts to back this up, it is only my theory.
Hook

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very good point about the big canopy and the aerodynamic limit. I guess I have been lucky with hard openings (triathlon,alpha, vengeance, FX (slight spank..rare now))
From precisions website they say they have 3 types of HMA on their canopies.
"Xaos-27 canopies (and other Ground Zero canopies) each contain three different sizes of HMA line including 352, 440, and 946-pound tensile strengths. The braided diameter is smaller than either Spectra or Vectran. "
"wee girls on a skydive road trip on big bikes...... yikes, dykes and bikes kinda thing...... ", David McKelvie

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I have exactly no experience with Nitrons....In my limited experience I seem to see the same types of canopies blowing out cells so I probably incorrectly blame the manufacturer and it never occured to me that it could be body position.
In fact the type of canopy I have seen blow up the most was blown up by the same person.(several heat waves).:D
ramon
"wee girls on a skydive road trip on big bikes...... yikes, dykes and bikes kinda thing...... ", David McKelvie

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This was my teammates canopy and has less than 30 jumps on it. When he first received it, it took 2000 feet to open. GZ said all 135's had similar characteristics and the hole in the slider was a standard modification. After further inconsistent and slow openings, Galaway told my teammate the canopy is not safe at his low wing loading and sent him a Nitro 150 to test (not GZ Nitron, but almost the same). My teammate was trying to sell the canopy and allowed the demo since the guy had sufficient skill set and wing loading. The guy made two uneventful jumps on the canopy before the mal. I also know he changed out the slider, but I don’t know if that was before or after the uneventful jumps. Even though the original had a hole, I know the Xaos has a much larger slider than most other canopies and curious to find out what size slider was swapped out. It did have all three line sizes, 352 on the inside, 440 on the outside, and 946 for brakes. I understand the small lines were the ones busted. Also curious how hard the opening was. I have had bruised ribs and a busted chin without breaking spectra. I don’t think most people know the difference between line dump and a stiff opening.

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