There is a flaw in the logic of both AAD's firing at the same time. Unless I'm mistaken (my girlfriend will tell you that happens often), the students AAD should have fired somewhere around 1200ft, unless the AAD was set for other firing parameters (human error?). There's no regulation requiring students in the U.S. to use AAD's with higher activation altitudes than experienced jumpers. The AAD's (presumably) involved may have had the same activation altitude.
How about the possibility that Argus AADs with Argus cutters slowed down the openings?
Again, when you start to consider the idea of gear or AAD malfunctions, you have to factor in that those are rare events, and would have had to happen twice on the same skydive.
In the student/instructor scenario, it's not unusual for an instructor to be very close or docked on a deploying student, or ever performing the deployment themseves. It also wouldn't be unusual for an instructor to be chasing a student having problems on the bottom end of a jump.
On a 'fun' jump, deployments are generally a solo event. and would be performed away from other jumpers. Even given a loss of altitude awareness, jumpers would tend to turn away from other jumpers before deploying if there was no time for a track. It would be very unusual for two fun jumpers to be in such close quarters under 1000ft., but these were not fun jumpers.
As to the AAD comment, I read a news article in which TK stated that they both had AADs and that both cutters had fired.
At Skydive City when it is known or suspected that jumpers landed off all jumpers on the load are asked to check in at manifest to ensure all are accounted for. Seems like a system to me.
Tell that to Janine who was laying in a field for several hours with a broken leg.
And these two were missing for TWO hours.
'when it is known or suspected' is NOT a process to account for each jumper.
Zhills is very good about going after people that land off. Zhills is very good about looking for someone when they KNOW they are missing. But the fact is that is NOT a process to account for each jumper.
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.
There is a flaw in the logic of both AAD's firing at the same time. Unless I'm mistaken (my girlfriend will tell you that happens often), the students AAD should have fired somewhere around 1200ft, unless the AAD was set for other firing parameters (human error?).
We don't even know the brand/model of the AAD's. FYI, here are the CYPRES activation altitudes: Expert: 750' Student: 1000' Tandem: 1900'
No one has yet to mention the Vigil and the possibility of a recent change in weather, as if a front was in the area,...
Personally there are so many troubling issues with this one, I'm going to loose sleep, I just know I am,...
My most heartfelt condolances, this totally sucks...
I can't help but think of the number of times I have been involved in conversations with students and the topic of disscussion has been the cost difference between cat a's and cat c/d's, this is really buggin me at the moment, and I can tell ya right now, even understanding that it's way to early to speculate, absent all the facts, I'm going to be a real prick the next time some student tells me that they want to progress because of money issues....
(And I am in no way making a wag regarding this issue and this student, who I am guessing, as so many students do, who put their complete faith in the system...)
Robert has hit the nail on the head here when he points out there is so much we don't know, other than this one is going to be spoken about for a long time, including the fact that by all apperances the instructor may have been focused upon saving the student at a very high personal cost...
when you start to consider the idea of gear or AAD malfunctions, you have to factor in that those are rare events, and would have had to happen twice on the same skydive.
I have to agree that it's unlikely. But I figure that if it's alright for a senior manufacturer with a dog in the fight and a bone to pick to start blaming and pointing fingers based on nothing more than the scant information we have, it must be ok for rabble like me.
I think I deserve the same chance to damage my credibility as well.
(This post was edited by gowlerk on Mar 25, 2013, 7:56 AM)
Well at this point we know nothing, we speculate everything and pointing fingers is the act of the day. What we do know is that Law enforcement, though well intention-ed, seems to almost always mess up the scene and reduce the ability of "qualified" people to investigate what happened. Getting gear all cut up and bundled up in a tub weeks serves little purpose in getting to the bottom of any incident. RIP brothers... will pray for your families.
Just a thought here, but what if the instructor was close to a dock, a little high, and over the student's back? How much, if any, would that impact the pressure reading?
I had a speculation close to that one... would 2 people in a close formation form some turbulence which would fool/bother the AAD's, and wouldn't the same turbulence also perturb a clean reserve deployment ?
billvon (D 16479)
Mar 25, 2013, 8:53 AM
Post #87 of 400
>would 2 people in a close formation form some turbulence which would fool/bother >the AAD's, and wouldn't the same turbulence also perturb a clean reserve deployment?
In my experience it will not fool an AAD (my experience is with a digital altimeter but they use the same sensing technique) but being close - specifically being docked - can cause significant spring loaded pilot chute hesitations.
I'm not sure how long it would take but machine a low pressure system moving in after takeoff.
I'm not a meterologist but I follow the weather a lot. Even a 10 point change in one hour, a difference of 100' in pressure altitude, is considered a very rapid rate. Three points on a 20 minute plane flight might make a 30' difference, maybe.
(This post was edited by JohnMitchell on Mar 25, 2013, 8:58 AM)
The burble hop scenario of Instructor / student would cause a lower pressure and higher indicated alt for the jumper above. Remember the chest mount altimeters and horny Gorillas at the bottom of the skydive. Always exciting! Shows how old I am.
(This post was edited by vpjr on Mar 25, 2013, 9:01 AM)
Expanding on the hypothesis that close proximity of jumpers could have potentially contributed to the reserve deployment issues. I am wondering what is actually known about the impact of bigger burble, created by two (or more) jumpers falling together, on the AAD triggered reserve deployments issues (especially reserve PC hesitations). Essentially, the question would be whether todayís riggs equipped in AADs are designed to safely deploy reserve in the close proximity to each other. There is a ton of real life experience and testing-based knowledge on this forum that could address this questionÖ.
but being close - specifically being docked - can cause significant spring loaded pilot chute hesitations.
This seems plausible to me. You see a lot of hesitations in AFF. It's why the main side leaves after the student pitches the pilot chute/pulls the ripcord. It takes very little pc hesitation to kill you below 750'.
Certain reserve pilot chutes perform better than others.
I am wondering what is actually known about the impact of bigger burble, created by two (or more) jumpers falling together, on the AAD triggered reserve deployments issues (especially reserve PC hesitations).
I don't know about the effects on an AAD, but I do know that on 2 instructor AFF jumps, the procedure is for the main side instructor to drop their grips and track away as soon as the PC is out of the pouch. The reserve side instructor hangs on until the deploying canopy pulls the harness grip from their hand. The idea is that the 3 way formation creates too much bruble for the student in the middle.
With regards to spring loaded pilot chutes, they have a proven track record of hesitations. Even on a solo jumper, if they have a clean, symetircal body position, the burble created is enough to slow the PC launch. Add another jumper docked on one side, and I can only imagine that it would be worse.
In this case, however, there would be two jumpers and two reserve PC launches in close proximity. Burble issues could be one thing, PC/freebag entanglements could be another, and canopy/jumper entanglements could be yet another.
Iím a bit confused here about the reliability of whatever is being put out. On the one hand, we have statements released saying that TK said that the reserves didnít open in time. On the other hand, weíre hearing that nobody viewed anything except for LEOs, who are not trained and donít know what happened.
My concern is that I donít even have any information that is stated as reliable that these jumpers werenít deceased before the AADs were deployed. I can certainly see a scenario where there was a midair that killed them and LEOs see people mashed up and assume the reserves didnít open on time.
I think thereís a whole lotta talk in a vacuum. There are assumptions that the reserves didnít open but I havenít seen any report that any riggers Ė or even experienced skydivers Ė have viewed the gear. Is there anything definitive to show that these two had malfunctions of AAD and canopy opening? Or just the statement that the reserves didnít open in time by someone who says he hasnít seen the gear?
On the one hand, we have statements released saying that TK said that the reserves didnít open in time. On the other hand, weíre hearing that nobody viewed anything except for LEOs,
I'm pretty sure the situation was that no jumpers were permitted on-site at the accident. The gear was removed from the jumper and the scene, and then jumpers (presumably TK) were allowed to inspect it at the police station later on, after it had been moved around and laid out in the police station.
The idea was that any clues you could get from the configuration of the gear 'as it lies' at the scene were lost to the LEOs moving things around. However, fired cutters, cut loops, and reserves out of freebags could lead to an accurate report of both AADs firing and canopies being partially deployed.
However, fired cutters, cut loops, and reserves out of freebags could lead to an accurate report of both AADs firing and canopies being partially deployed.
I'm not questioning that the AADs fired. I'm wondering whether either of the jumpers was conscious when it happened. Is there anything that says they were or were not? Both being knocked out can certainly explain why both AADs fired.
Do we know that the reserves did not open completely?
I'm not questioning that the AADs fired. I'm wondering whether either of the jumpers was conscious when it happened. Is there anything that says they were or were not? Both being knocked out can certainly explain why both AADs fired. ?
one o fthe news reports said that 1 of rthe jumpers was jumping with a camera and that it would be used by the police. Presumably the instructor and not the 8 jump student.