Two out with a lineover

[jerry81 10]

Saw it a few hours ago. The only reason this is not in incidents is dumb luck, since the string of mistakes is pretty apparent: A jumper with around 50 jumps, on student status (different rules in this country), first jump with a hand-deployed pc- I watched him do practice pulls on the ground, he said he practiced reaching for the handle in freefall (jump was from 2000m), but he apparently had trouble finding it when it was time to pull and opened somewhere between 500 and 700 meters (watching from the ground, it seemed closer to 500). The canopy (Skymaster 270), in accordance with Booth's Law #1, opened slow and with a lineover, which the jumper fought to correct until the aad (FXC12000) deployed his reserve (unknown, probably in the 250 range, since that's what most of our student rigs hold).

I assume it was the unstable main that caused the canopies to go from a biplane to a brief side-by-side to a something resembling a slow down plane in a couple of seconds. The downward speed didn't seem high enough to be fatal, but I'm sure it would be enough to break a leg or two. Thankfully, instead of hitting a nearby road, the guy rode the mess down and landed in some trees from which we retrieved him unhurt in no time at all. The canopies took a bit longer, but from what I've seen there hasn't been any damage to them either.

Besides the obvious lessons, I'm curious if there have ever been any experiements with two-out situations where one of the canopies is 'aerodinamically challenged'. I've thought about it and it seems to me in this case, the possibility of a stable configuration is pretty small. Am I right?

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[funks 1]

are you sure the aad fired the reserve? Doesnt seem like he would have enough speed for that to happen since the main was out???

[bch7773 0]

well, since the main had a lineover, it has a higher decent rate, plus if the jumper was in a turn or a spiral...

also, im not sure what decent rate a FXC requires to fire reserve

MB 3528, RB 1182

[jerry81 10]

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are you sure the aad fired the reserve? Doesnt seem like he would have enough speed for that to happen since the main was out???

Yes, it was definitely the aad that opened the reserve. There is a chance, though, that it happened just as the main was deploying (wouldn't be the first time that an FXC fired higher than it was set) and the reserve pc dragged behind him for a while before pulling everything out.

The FXC is set to always fire when the descent rate is above 65fps and never fire when it's below 40fps. The lineover on the main looked about 3 cells from the edge and while it definitely wasn't a high speed malfunction, it was dropping noticeably faster than a normally flying canopy of that size.

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[bigway 4]

My understanding is that if you are coming down in a 182 you should turn your FXC off or it could fire. Sounds like the reate of decent needed can not be much.

.Karnage Krew Gear Store
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[JohanW 0]

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[snip]

Besides the obvious lessons, I'm curious if there have ever been any experiments with two-out situations where one of the canopies is 'aerodynamically challenged'. I've thought about it and it seems to me in this case, the probability of a stable configuration is pretty small. Am I right?

Some time ago I heard about a two out with both canopies in a twist. While this may not count as fully 'aerodynamically challenged' it was definitely enough to get me to consider two-out scenarios beyond the normal 'flying straight and level.'

This developed into either a side-by-side or a biplane, but apparently flew stable.

It did, however, turn downwind, and the guy didn't like the speed over the ground, and chopped the main. The canopies entangled at first, then the main got away from the reserve, helped by the fact that there was only a single twisted strand of lines, and he managed to untwist his reserve before landing (downwind). I personally think he was lucky.

So, yes, with one or both canopies in a twist, the resulting configuration might be stable. Based on this n=1 unplanned experiment, it would seem that a stable configuration, albeit with a twist, is better left alone.

The probability of a stable configuration with either canopy having a line-over however seems astronomical. A line-over normally doesn't fly straight.

Johan.
I am. I think.

[winsor 186]

Besides the obvious lessons, I'm curious if there have ever been any experiements with two-out situations where one of the canopies is 'aerodinamically challenged'. I've thought about it and it seems to me in this case, the possibility of a stable configuration is pretty small. Am I right?

[jerry81 10]

The following is a lesson in how even first-hand accounts of incidents can be completely off:

We watched the video of this mishap several times tonight. It was the reserve that was open and what appeared to us as a lineover was actually caused by the lines of the (uninflated) main across the canopy. This means the aad fired at about the same time as the jumper finally found the pc handle, the reserve opened first and the main (possibly its pilot chute, this is not clear from the video) got entangled on the left side. After a few spirals, the main slid off and inflated, which then quickly led to a downplane.
The student himself gave roughly the same story as I initially posted (lineover on main, followed by an aad fire).

I apologise for the confusion. If it was still possible, I'd change the title of this thread to (now even more appropriate) "One extremely lucky SOB". (edit @Winsor: Seems it was more like a cannonball that he dodged...)

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[LannerFalcon 0]

[

The lessons learned here are:

1) Stay the hell out of the basement.

2) If you have a malfunction and the reserve appears of its own volition, GET RID OF THE MAIN!

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Disagree with point 2, it is recommended you DON'T cut away in certain situations, for example:

Stable biplane with reserve at rear, the risk of a main entanglement with the reserve following cutting is far greater, than what will nearly always be a stable soft landing.

Here is the PD findings:

http://www.bpa.org.uk/skydive/pages/articles/aug03/canopiesout.html

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Break now Jester!

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[winsor 186]

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[

The lessons learned here are:

1) Stay the hell out of the basement.

2) If you have a malfunction and the reserve appears of its own volition, GET RID OF THE MAIN!

Quote

Disagree with point 2, it is recommended you DON'T cut away in certain situations, for example:

Stable biplane with reserve at rear, the risk of a main entanglement with the reserve following cutting is far greater, than what will nearly always be a stable soft landing.

Here is the PD findings:

http://www.bpa.org.uk/skydive/pages/articles/aug03/canopiesout.html

I'm familiar with that.

You will note that I specified "malfunction," not simply two out. Big difference.

Your likelihood of having a stable biplane when you started out with a spinning malfunction is nil.


Once you have transitioned past a sideplane, it behooves you to get rid of the main STAT - at least if landing without serious injury or death is a consideration.


Blue skies,

Winsor

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[LannerFalcon 0]

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[

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I'm familiar with that.

You will note that I specified "malfunction," not simply two out. Big difference.

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Fair cop.

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Break now Jester!

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[bmcd308 0]

My friend Jason had a two out where the main opened with many line twists through the hole in the center of the reserve created by two cells blowing out. It was NOT a stable configuration. There is a thread in the incidents forum.

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