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a spinning opening ?

 


Auryn  (D 27808)

Dec 1, 2003, 11:50 PM
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a spinning opening ? Can't Post

I jump a Jonathon 120 1.6:1
Yesterday I threw out and had a spinning opening. I first thought it was a released brake but after reviewing the video frame by frame I know the brakes are stowed.

the canopy spun to right, and I had 1 end cell closed on the left side of the canopy. From what I saw, everything else with the canopy was fine...

when it was happening, I immediately gave it all the left riser I could, which didnt do squat to slow it down. I then pumped the left riser twice, and following the twice rule, gave up on that and then went to fire my brakes and after pumping them twice the canopy was flying straight.

it was a serious spin. total elapsed time from slider down to flying straight was 5 seconds. I had completed almost 3 full revolutions during that time Unimpressed it was more extreme than any spiral I have intentionally done with the canopy.

this wingloading is new to me, so I want to know everything I can about it.



It may be a stupid question, but I had to ask. I've never had end cell closure on my 150 at 1.3:1 cause ANY problems. I would think the closure being on the left would cause the canopy to spin left since there is more parachute flying on the right. So Im a bit confuzzed.

Blue Ones !

D-27808


Premier billvon  (D 16479)
Moderator
Dec 2, 2003, 9:57 AM
Post #2 of 8 (857 views)
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Re: [Auryn] a spinning opening ? [In reply to] Can't Post

>I then pumped the left riser twice, and following the twice rule, gave
> up on that and then went to fire my brakes and after pumping them
> twice the canopy was flying straight.

This can be a dangerous thing to do. On many canopies, you can 'trap' the brake lines in the twists, and if you release them, they may come down when you pump them but not go back up. It might be worth it if the only other option is a cutaway.

Also, make sure you don't mess with problems like this too long. Two attempts to correct it, then chop it. You can lose 1000 feet in 10 seconds under a highly loaded elliptical if it really starts to spin.

>this wingloading is new to me, so I want to know everything I can >about it.

Well, you just learned one thing, which is that line twist may now be a malfunction. It's one of the drawbacks of higher wing loadings.

>. I would think the closure being on the left would cause the canopy
>to spin left since there is more parachute flying on the right. So Im a
>bit confuzzed.

Or there's less drag on the left so the left side of the canopy "flies faster." It depends on the canopy and the particular problem (i.e. line twist with one riser low can cause a turn.)


Auryn  (D 27808)

Dec 2, 2003, 1:40 PM
Post #3 of 8 (822 views)
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Re: [billvon] a spinning opening ? [In reply to] Can't Post

In reply to:
>I then pumped the left riser twice, and following the twice rule, gave
> up on that and then went to fire my brakes and after pumping them
> twice the canopy was flying straight.

This can be a dangerous thing to do. On many canopies, you can 'trap' the brake lines in the twists, and if you release them, they may come down when you pump them but not go back up. It might be worth it if the only other option is a cutaway.

Also, make sure you don't mess with problems like this too long. Two attempts to correct it, then chop it. You can lose 1000 feet in 10 seconds under a highly loaded elliptical if it really starts to spin.

>this wingloading is new to me, so I want to know everything I can >about it.

Well, you just learned one thing, which is that line twist may now be a malfunction. It's one of the drawbacks of higher wing loadings.

>. I would think the closure being on the left would cause the canopy
>to spin left since there is more parachute flying on the right. So Im a
>bit confuzzed.

Or there's less drag on the left so the left side of the canopy "flies faster." It depends on the canopy and the particular problem (i.e. line twist with one riser low can cause a turn.)

this was caused by the closed end cell alone, I didnt have any line twists. I guess my specific question is, can a closed end cell possibly cause a canopy to spin this bad at 1.6:1 or was there something else probably going on that I couldn't see ? I didn't have any line twists which is why I popped the brakes to try to get it to stop..

thanks for the info, Im a little clearer on why it spun to the right, a reverse of what I would logically think, but I know once you get some loading things about canopy behavior change.

blue Ones !

D 27808


bodypilot1  (D 16037)

Dec 2, 2003, 8:36 PM
Post #4 of 8 (786 views)
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Re: [Auryn] a spinning opening ? [In reply to] Can't Post

In reply to:
I jump a Jonathon

Here's your problem?TongueSly


Auryn  (D 27808)

Dec 2, 2003, 9:19 PM
Post #5 of 8 (778 views)
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Re: [bodypilot1] a spinning opening ? [In reply to] Can't Post

In reply to:
In reply to:
I jump a Jonathon

Here's your problem?TongueSly

hey now.. I have 200 jumps on a 150 I love, it honestly is a great canopy, never had any problems... it was great in every way for what I needed it for. The 120 on the other hand..... very different. Im glad I am just demoing it and havent bought it. I allready have decided on a Jedi 120. But, what happened on this opening could happen on any canopy I would imagine. I talked to my rigger and he has surmised that it was a linover on the left that cleared when I pumped the toggles, or a steering line inversion that cleared when I pumped the toggles. Closed end cells alone could not cause a spiral this severe.

the flight chars. of the 120, to be positive are: slow openings, but unpredictable. snappier turns than any other 120 I have jumped. smooth riser inputs both front and back, but somewhat stiff pressure. soft landings straight in. swooping, cannot comment on, I don't have enough time to swoop it of course.

Blue Ones !

D 27808


hookitt  (D License)

Dec 3, 2003, 12:37 PM
Post #6 of 8 (731 views)
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Re: [bodypilot1] a spinning opening ? [In reply to] Can't Post

Come on Ed, I have hundreds of jumps on a Jonathon. It's not that spectacular of a canopy but it opened and flew just fine. I know of many others that we're just fine as well.

On-the-other-hand.... Ed's got a good point... Here's why.

The Jonathon is no longer manufactured. Almost every Jonathon was different from the previous. Tony Uragallo(sp?) had a tendency to make changes on the fly, so the design consistancy of the canopy was pretty much zero.

End cell closure on my parachute meant pump the brakes once or twice. I never had line twists that went into a spiraling dive. However, I've demoed a few Jonathons that had no business being placed in service.

Basically, you kinda take your chances with a Jonathon.


bodypilot1  (D 16037)

Dec 4, 2003, 9:01 AM
Post #7 of 8 (667 views)
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Re: [hookitt] a spinning opening ? [In reply to] Can't Post

In reply to:
Jonathons that had no business being placed in service.

Basically, you kinda take your chances with a Jonathon.

I have jumped a few also, and like I said......

In reply to:
I jump a Jonathon

Quote:
"Here's your problem?"Sly

Ed
AFF-I/T-I/BM-I


hookitt  (D License)

Dec 4, 2003, 1:13 PM
Post #8 of 8 (633 views)
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Re: [bodypilot1] a spinning opening ? [In reply to] Can't Post

Your answer was a bit shy of information so I found it to be useless. I thought perhaps it would be a good Idea to extrapolate and add some information.

I'm pretty sure this part and the part after this: On-the-other-hand.... Ed's got a good point... Here's why. was the part where I agreed and added some info that was neglected in your post.

Thank you and good night.. I'll be here all week.



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