Forums: Skydiving: Incidents:
Double Fatality - Zhills 3-23-13

 

First page Previous page 1 2 3 4 5 6 7 8 9 10 ... 16 Next page Last page  View All

Premier billvon  (D 16479)
Moderator
Mar 25, 2013, 5:10 PM
Post #126 of 400 (5021 views)
Shortcut
Re: [MikeMedv] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

> If you double your freefall speed, the canopy hits line stretch much quicker, because
>you cover the same distance in half the time.

That's a false assumption. Almost nothing in the scenario you described scales linearly. Fast freefall rates are indeed a problem for AAD's - in general a 700 foot firing altitude is not high enough for someone going well above normal freefall speeds (like head-downers.)


tkhayes  (D 18764)

Mar 25, 2013, 5:18 PM
Post #127 of 400 (5012 views)
Shortcut
Re: [theonlyski] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

this is all you are getting for now folks, more to come, but the video has not been seen by us (at least) yet
TK
Attachments: Press Release 03242013.pdf (39.4 KB)


danornan  (D 11308)

Mar 25, 2013, 6:11 PM
Post #128 of 400 (4886 views)
Shortcut
Re: [tkhayes] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

Thanks TK


evan85  (C 41367)

Mar 25, 2013, 6:29 PM
Post #129 of 400 (4817 views)
Shortcut
Re: [normiss] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
It appears that both AAD's operated within their firing parameters.

The only information I've seen (please correct me if I'm wrong) is that both AADs fired. They could have fired at 840ft, or at 40ft. Until we know that, I don't think you can say that they operated within their firing parameters.


JohnSherman  (D 2105)

Mar 25, 2013, 8:42 PM
Post #130 of 400 (4562 views)
Shortcut
Re: [gregpso] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

Quote:
How about raising activation heights to 1500 feet for students and 1000 feet for expert .. add extra margin of safety. why 750 feet ? hang on I think mr Booth has already raised this !!

When you understand the problem you will understand that raising the altitude will not help. Those reserves wouldn't open in 2000 feet.
If you can't get the bag out of the container you can't get the canopy out of the bag.


Phillbo  (B License)

Mar 25, 2013, 8:46 PM
Post #131 of 400 (4552 views)
Shortcut
Re: [JohnSherman] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

Can someone explain to me the reason for the student parameters here?


FYI, here are the CYPRES activation altitudes:

Expert:
- 750' & velocity > 78mph

Student:
- 1000' & velocity > 29mph & velocity < 78mph
- 750' & velocity > 78mph

Tandem:
- 1900' & velocity > 78mph


evan85  (C 41367)

Mar 25, 2013, 9:01 PM
Post #132 of 400 (4518 views)
Shortcut
Re: [JohnSherman] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
Quote:
How about raising activation heights to 1500 feet for students and 1000 feet for expert .. add extra margin of safety. why 750 feet ? hang on I think mr Booth has already raised this !!

When you understand the problem you will understand that raising the altitude will not help. Those reserves wouldn't open in 2000 feet.
If you can't get the bag out of the container you can't get the canopy out of the bag.

Not trying to be contrary, just trying to figure out if I missed something. What facts do you have to support your theory that the malfunction here was that both instructor and student's freebags were stuck in their respective containers?


ryoder  (D 6663)

Mar 25, 2013, 9:05 PM
Post #133 of 400 (4508 views)
Shortcut
Re: [Phillbo] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
Can someone explain to me the reason for the student parameters here?


FYI, here are the CYPRES activation altitudes:

Expert:
- 750' & velocity > 78mph

Student:
- 1000' & velocity > 29mph & velocity < 78mph
- 750' & velocity > 78mph

Tandem:
- 1900' & velocity > 78mph

The idea is that in the event of a partial mal, the activation altitude bumps up to 1000'.


stratostar  (Student)

Mar 25, 2013, 9:08 PM
Post #134 of 400 (4499 views)
Shortcut
Re: [JohnSherman] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

Quote:
If you can't get the bag out of the container you can't get the canopy out of the bag.

Yep, I said the same thing and some are kind of quick discount that theory, yet I think you know WTH you are talking about and I agree. Without seeing the name brand, not that it matters.... but we have seen a hand deployed reserve on a POV vid not all that long ago and had that jumper not done a hand deploy on that stuck free bag he would dead, and there have been others who went in for the same reason... I believe that you would state that is the problem or problems you have already addressed here and other venues as well.

Now that you have said too, maybe less people will discount the theory that was put forth. It will interesting to learn more about the gear used on this accident. Then again, there are rumors that might blow that theory in regards to this accident.... however I still believe your are correct in regards to the issue you bring up.


(This post was edited by stratostar on Mar 25, 2013, 9:36 PM)


JohnMitchell  (D 6462)

Mar 26, 2013, 2:54 AM
Post #135 of 400 (4282 views)
Shortcut
Re: [Liemberg] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
Skydiving Instructors used to get paid for pulling above 2000ft AGL, giving their student a clear visual signal that if they were not already under a parachute it would be an excellent idea to do so, ASAP.
They still do, in my book. Sorry, but I'm not chasing you below 2000'. Then it's up to you, God, and the AAD I set before I geared you up.


airdvr  (D 10977)

Mar 26, 2013, 5:26 AM
Post #136 of 400 (4065 views)
Shortcut
Re: [JohnMitchell] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

No one has brought up the possibility of complete loss of altitude awareness. It seems almost impossible today but used to be a couple of those types of bounces every year.


JohnMitchell  (D 6462)

Mar 26, 2013, 7:58 AM
Post #137 of 400 (3782 views)
Shortcut
Re: [airdvr] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
No one has brought up the possibility of complete loss of altitude awareness. It seems almost impossible today but used to be a couple of those types of bounces every year.
Very true. I lost more than one friend that way.


freeflyer58D  (B 32456)

Mar 26, 2013, 8:02 AM
Post #138 of 400 (3766 views)
Shortcut
Re: [airdvr] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

this is completely an out there idea, but... what altimeter were they using? was it metric or imperial? I have borrowed equipment many times while jumping with big groups. is it possible that they grabbed one set for feet? being at 1000m is nothing to worry about. 1000f is a very different story. add in the low scattered layer. even if they knew it was in feet, it is easy to fall back to habits. as for the AAD and the reserve not getting open, that is a separate issue. i care more about what put two people deep in the corner.


gofastfrance  (D License)

Mar 26, 2013, 8:13 AM
Post #139 of 400 (3741 views)
Shortcut
Re: [Skydivesg] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

Just something I thought about reading your post.

How does the Vigil know you are not in a stable belly to earth position?
First time I hear about this.

Thanks


chuckakers  (D 10855)

Mar 26, 2013, 8:25 AM
Post #140 of 400 (3704 views)
Shortcut
Re: [Ron] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
In reply to:
In reply to:
In reply to:
It doesn't seem like a check in/jumper accountability conversation is relevant here, they were found quickly.

You understand the jump at at 1030 and the discovery was 1930?

They were 'missed' quickly...they were 'found' after an extensive search.

'Hayes said the men did not return for two hours, prompting worries among the group.'

I do not consider two hours quick.

Don't get me wrong... I don't think there was much of anything zhills could have done better. I think it is the responsibility of the jumpers to keep track of the people in your group. Zhills does a fantastic job, but what they are doing is NOT a system to track each jumper.

Given the crappy reporting techniques among media these days, I'm not sure I would take a comment that folks were concerned when the jumpers failed to return after 2 hours to mean that a search wasn't started until then.

It is possible that the search was started shortly after the jumpers failed to return AND people were concerned after 2 hours.


Ron

Mar 26, 2013, 8:42 AM
Post #141 of 400 (3663 views)
Shortcut
Re: [chuckakers] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

Quote:
It is possible that the search was started shortly after the jumpers failed to return AND people were concerned after 2 hours.

The point still stands... Zhills has no 'system' to track jumpers.

To the accident.... I am going opine that it was an unstable student with the 'I' chasing him to the basement. The students AAD fired and the 'I' was caught up in the lines when his AAD also fired. Both people were now entangled in lines and neither canopy had a good chance at deployment. <---- Pure speculation, but the only solution that makes sense to me right now.


(This post was edited by Ron on Mar 26, 2013, 8:54 AM)


ryoder  (D 6663)

Mar 26, 2013, 8:53 AM
Post #142 of 400 (3616 views)
Shortcut
Re: [gofastfrance] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
Just something I thought about reading your post.

How does the Vigil know you are not in a stable belly to earth position?
First time I hear about this.

Thanks

He is saying that the actual setting is 1100', but due to the low pressure area on the jumpers back in belly flight, (where the unit is located), it won't fire until 840'. i.e. if the jumper is not in belly position, it will fire at 1100'.


CSpenceFLY  (D 25252)

Mar 26, 2013, 9:12 AM
Post #143 of 400 (3557 views)
Shortcut
Re: [Ron] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
Quote:
It is possible that the search was started shortly after the jumpers failed to return AND people were concerned after 2 hours.

The point still stands... Zhills has no 'system' to track jumpers.

To the accident.... I am going opine that it was an unstable student with the 'I' chasing him to the basement. The students AAD fired and the 'I' was caught up in the lines when his AAD also fired. Both people were now entangled in lines and neither canopy had a good chance at deployment. <---- Pure speculation, but the only solution that makes sense to me right now.


A second for this. If they have video we should know in a month or two.


normiss  (D 28356)

Mar 26, 2013, 9:15 AM
Post #144 of 400 (3540 views)
Shortcut
Re: [CSpenceFLY] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

I was told it did not appear they were entangled and were found very close yet separate. All gear in a very small area.


chuckakers  (D 10855)

Mar 26, 2013, 9:24 AM
Post #145 of 400 (3515 views)
Shortcut
Re: [CSpenceFLY] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
In reply to:
Quote:
It is possible that the search was started shortly after the jumpers failed to return AND people were concerned after 2 hours.

The point still stands... Zhills has no 'system' to track jumpers.

To the accident.... I am going opine that it was an unstable student with the 'I' chasing him to the basement. The students AAD fired and the 'I' was caught up in the lines when his AAD also fired. Both people were now entangled in lines and neither canopy had a good chance at deployment. <---- Pure speculation, but the only solution that makes sense to me right now.


A second for this. If they have video we should know in a month or two.

Correct me if I missed something, but I don't think the type off AAD's or activation altitudes have been made public. So yes, speculation on a grand scale.


jimmytavino  (A 3914)

Mar 26, 2013, 9:32 AM
Post #146 of 400 (3494 views)
Shortcut
Re: [normiss] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
I was told it did not appear they were entangled and were found very close yet separate. All gear in a very small area.



Frown

reserve slider(s) up at the canopy?? or down at the links ?
how far away were the freebags?
what were the ground winds??? if any?

sorry for the heartache suffered by All @ the DZ...


Unsure


Skydivesg  (D 10938)

Mar 26, 2013, 9:46 AM
Post #147 of 400 (3429 views)
Shortcut
Re: [gofastfrance] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
How does the Vigil know you are not in a stable belly to earth position?
First time I hear about this.

The Vigil does not know what your body position is nor does it care. It actually does not even know you are in free fall. Testing is done in a controlled pressure chamber.

The device is designed to sense barometric pressure (which increases as we get closer to the ground) . It also measures the time it takes for that pressure to increase. It then combines that information and using algorithms determines the speed at which the pressure is building. When the speed and altitude meet specific parameters the device sends a signal to the cutter to activate.

The unit has a pressure sensor which is usually inside your reserve pack tray. That sensor is what measures the barometric pressure. When we fall face to earth we create a low pressure area just above our body. This low pressure causes the sensor to read our altitude as higher than we actually are. The difference can be as much as 260 feet which is why the company added 260 feet to activation altitude.

So the Vigil PRO mode is designed to activate no lower than 840 feet AGL but could fire as high as 1100 feet.

I hope that helps.

.Be the canopy pilot you want that other guy to be.




airdvr  (D 10977)

Mar 26, 2013, 10:29 AM
Post #149 of 400 (3314 views)
Shortcut
Re: [CSpenceFLY] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

I'll add another possibility. Possibly the AAD was not reset for ground level in ZHills.


BillyVance  (D 18895)

Mar 26, 2013, 10:32 AM
Post #150 of 400 (3299 views)
Shortcut
Re: [airdvr] Missing jumpers. Zhills 3-23-13 [In reply to] Can't Post

In reply to:
I'll add another possibility. Possibly the AAD was not reset for ground level in ZHills.

How do you turn on an AAD and not have it reset to ground level at Zhills if you turn it on there? I'm not following...


First page Previous page 1 2 3 4 5 6 7 8 9 10 ... 16 Next page Last page  View All

Forums : Skydiving : Incidents

 


Search for (options)