May 12, 2009, 9:17 AM
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reserve deployment hesitations
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In light of the recent incident at Perris and previous reserve deployment hesitations I really would like to know if there has been any "official" studies on ideal body position to enhance rapid deployment of the reserve. In the incidents it was mentioned that JS actually did recomend a head high position. Does any other manufacturer give advice? Definitely sounds like this could/should be added to our pre-jump mental EP's.
billvon (D 16479)
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May 12, 2009, 11:04 AM
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>Definitely sounds like this could/should be added to our pre-jump mental EP's.
I would suggest that pulling the reserve by 1600 feet (thus providing time for RPC hesitations) would be preferable to intentional instability after a reserve pull.
I doubt that any mfr would give you anything more than an informal comment. Anything else might just lead to some unintentioned liability.
No TSO standard that I know has any mention of the attitude of the dummy during any of the drop tests.
Here is a photo of a drop test dummy that was put out of the aircraft ( Cessna ) in an upright position. As you can see ( hopefully, as this is a poor photo since it was scanned from an actual picture ) the dummy is now belly-up and upside down.
I had one mfr once tell me that to get some item through the 3-second requirement they had to slide the dummy out of the aircraft on a piece of plywood so that they could control the orientation of the dummy, as much as possible, through the deployment. If they didn't, they could not meet the 3-second requirement.
It's a sticky situation since, in today's world, the AAD activation level has gone down to 750 ft. Perchance moving it back up to 1,000 ft might be the better thing to do.
Just my two cents,
JerryBaumchen
Edit: Sorry, wrong photo.
(This post was edited by JerryBaumchen on May 12, 2009, 1:46 PM)
Perchance moving it back up to 1,000 ft might be the better thing to do.
I have thought about this alot of times. Do you know if i can get my cypress 2 changed by the manufactor?
No you can not. You have the option to manually set it before each jump to a different altitude. It's designed that way in case the take off point and landing zone are at different altitudes. Remember though, every jump. Not just once in the morning.
If you truly want it to fire higher, set the *landing zone* higher. Read the manual. Learn how it works.
Perchance moving it back up to 1,000 ft might be the better thing to do.
I have thought about this alot of times. Do you know if i can get my cypress 2 changed by the manufactor?
No you can not. You have the option to manually set it before each jump to a different altitude. It's designed that way in case the take off point and landing zone are at different altitudes. Remember though, every jump. Not just once in the morning.
If you truly want it to fire higher, set the *landing zone* higher. Read the manual. Learn how it works.
Thanks i understood you could do that I was just hoping they could reprogram and make it perminant.
billvon (D 16479)
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May 12, 2009, 4:11 PM
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>It's a sticky situation since, in today's world, the AAD activation level has >gone down to 750 ft.
The Cypres (which I consider to be the first modern AAD) has always been around 750 feet. There were earlier AAD's like the FXC which had higher (often adjustable) setpoints, but in general they were higher because the device was less accurate. In other words, if you wanted to be sure you had an open canopy by 800 feet you had to set it to 1300, and then it might fire somewhere between 800 and 1800.
To me, an AAD should do exactly one job - begin the opening of your reserve when there is almost no time remaining for you to do it. IMO, the best AAD's out there do nothing when there's any question whether or not you are currently dealing with the problem.
Thanks i understood you could do that I was just hoping they could reprogram and make it perminant.
I'm with you; I think it would be a nice option to have.
Too bad one of them doesn't offer it; might just generate a few more sales opportunities.
JerryBaumchen
PS) Or 'you' could organize a letter-writing campaign.
it would also open up more room for human error. I happen to like the factory setting
Yes it would but that could be decided by the individual operator of each device. I nor anyone else is saying that all aad's should operate at a higher altitude, but some of us may want the option. I personally pull higher than alot of skydivers. I pull between 4k and 3.5 k on almost all of my jumps. I am not that worried about a 2 out. Im not one of them dirty low pullers. But most of my jumps are FF jumps and i think with the higher speeds i have a better chance of being knocked out. But i only jump in groups with people i trust and if im jumping with a newer jumper or someone i dont know or someone else can not tell me how good the are then i will do a solo with them and trust that i can get out of there way if need be.
I have thought about this alot of times. Do you know if i can get my cypress 2 changed by the manufactor?
No you can not. You have the option to manually set it before each jump to a different altitude. It's designed that way in case the take off point and landing zone are at different altitudes. Remember though, every jump. Not just once in the morning.
If you truly want it to fire higher, set the *landing zone* higher. Read the manual. Learn how it works. Thanks i understood you could do that I was just hoping they could reprogram and make it perminant. Other AAD's can do this and do not need to be reprogrammed before each jump. It's your choice. But be aware of the higher risk to get a two out situation.
Thanks i understood you could do that I was just hoping they could reprogram and make it perminant.
I'm with you; I think it would be a nice option to have.
Too bad one of them doesn't offer it; might just generate a few more sales opportunities.
Since later 2006, they have offered a feature that would offer the last used offset at the beginning of the sequence. This would be added during the maintenance cycle.
Not a perm change, but perhaps better anyway - less potential for confusion/screwup.
>Definitely sounds like this could/should be added to our pre-jump mental EP's.
I would suggest that pulling the reserve by 1600 feet (thus providing time for RPC hesitations) would be preferable to intentional instability after a reserve pull.
Point taken-I was just thinking back to student days of ripcord mains where I was taught to check over your shoulder if nothings happening after pulling.-simple and quickly made type of move.
(This post was edited by bigbearfng on May 13, 2009, 7:29 AM)
After watching lots of video of reserve deployments and more than twenty reserve rides, I have concluded that the ideal body position - to deploy a reserve pilot chute is head high (spine 45 to 60 degrees from horizontal). That way, the air flow up your back can quickly eliminate any pilot chute hesitation. Coincidentally, that is about the same angle you will be at when an RSL pulls your reserve ripcord. Keep in mind that body position varies wildly depending upon how badly you are spinning under a malfunction, but pulling a reserve ripcord a half second after cutting away is usually the best plan.
billvon (D 16479)
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May 13, 2009, 10:37 AM
Post #15 of 37
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> where I was taught to check over your shoulder if nothings happening >after pulling.-simple and quickly made type of move.
Sorry, I misunderstood what you were getting at, then! I agree that the checking-over-your-shoulder is a good idea, both from a perspective of seeing what's going on and helping break up any burble that might be back there. Ideally you could stay belly-to-earth while you did that.
LouDiamond (D 25931)
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May 13, 2009, 1:27 PM
Post #16 of 37
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The solution to this is actually nothing new. However, a majority of the people skydiving have never or have very limited experience with a spring loaded main and reserve pilot chute. The Military however still uses spring loaded PCs on the main and reserve and standard operating procedure following deployment of the main or reserve canopy is to vigorously check over the right shoulder to ensure the PC isn't bouncing around in the burble.
PC hesitation is a big issue in the military and I've been fortunate to have worked on a CFD (computational fluid dynamics) program that addresses this problem, especially with the addition of equipment on the jumper. Having personally done it in the air and seen it in the CFD program, the simple act of vigorously checking over the shoulder changes the airflow over the back of the jumper enough to usually eliminate any PC hesitation, this is especially true of a jumper without any additional equipment attached to them.
The head high orientation does work ,however it's typically not an orientation a skydiver finds themselves in when in normal freefall at pull time. Conversely, head low has a similar effect and in some cases this can be the jumpers orientation during the pull sequence either due to poor body position and or severely dropping a shoulder. The result is a less than desirable opening shock usually. For the standard flat dumb and happy body orientation, the shoulder check is proven to work.
The Military however still uses spring loaded PCs on the main and reserve and standard operating procedure following deployment of the main or reserve canopy is to vigorously check over the right shoulder to ensure the PC isn't bouncing around in the burble.
Kind of an apples and oranges thing. The system in that video is nothing like what is used for HALO or civilian operations today. There is/was more than a PC hesitation issue with that system, which dates back to the 50's.
The solution to this is actually nothing new. However, a majority of the people skydiving have never or have very limited experience with a spring loaded main and reserve pilot chute. The Military however still uses spring loaded PCs on the main and reserve and standard operating procedure following deployment of the main or reserve canopy is to vigorously check over the right shoulder to ensure the PC isn't bouncing around in the burble.
Before hand deploy came along, all skydiving deployments were by ripcord and spring loaded pilot chutes. Hesitations were common, everybody had them and they were accepted as a fact of life. Training focused a lot more on the problem. And then Bill Booth invented hand deploy. I still remember Memorial Day, 1976 when a friend of ours showed us all his brand new Wonderhog and explained to us how the new "hand deploy" system worked. It worked so well that within two years almost everyone had switched over to a hand deployed rig. It was great - almost overnight p/c hesitations had been almost completely eliminated.
What it comes down to though, is that ripcord deployment is a SKILL, that has to be learned and mastered, like any other skill. And it isn't being treated like a skill. For thirty years now, newbies have only been trained to pull their handles in an emergency, as if that gets the job done all by itself. Thankfully for the most part it has. But the truth is, "it ain't open 'til it's open" and we are occasionally seeing reserves open too low to prevent serious injuries or death.
There needs to be more training. Skydivers today don't pull a ripcord until they're already in trouble and going low. That's no time to start learning a new skill. As in the old days, a certain amount of hesitation has to be accepted as a fact of life and there has to be more training focused on anticipating and dealing with the problem effectively.
(This post was edited by tbrown on May 16, 2009, 10:43 PM)
After watching lots of video of reserve deployments and more than twenty reserve rides, I have concluded that the ideal body position - to deploy a reserve pilot chute is head high (spine 45 to 60 degrees from horizontal). That way, the air flow up your back can quickly eliminate any pilot chute hesitation. Coincidentally, that is about the same angle you will be at when an RSL pulls your reserve ripcord. Keep in mind that body position varies wildly depending upon how badly you are spinning under a malfunction, but pulling a reserve ripcord a half second after cutting away is usually the best plan.
...which is why I think there needs to be more debate over whether "pull silver and arch" should be trained into the EP's.
There needs to be more training. Skydivers today don't pull a ripcord until they're already in trouble and going low. That's no time to start learning a new skill. As in the old days, a certain amount of hesitation has to be accepted as a fact of life and there has to be more training focused on anticipating and dealing with the problem effectively.
Agreed - remember how we all used to be trained to check over your shoulder after ripcord pull - not only to check that the PC has launched, but to break the burble and send the relative wind across your back. Seems sensible to do that after reserve pull now, rather than just arching "to get stable". "Stable" creates the burble.
(This post was edited by Andy9o8 on May 17, 2009, 7:16 AM)
Something I learned during my last ride on a round reserve ... tuck your legs back, BEFORE pulling the cutaway handle. Tucking your legs back prevents the whole backlooping through your reserve suspension lines hassle. Fortunately I was quick on the reserve ripcord and did not backloop far enough to interfere with reserve deployment, but it was a scary sensation!
Agreed - remember how we all used to be trained to check over your shoulder after ripcord pull - not only to check that the PC has launched, but to break the burble and send the relative wind across your back. Seems sensible to do that after reserve pull now, rather than just arching "to get stable". "Stable" creates the burble.
I was just reading through this thread thinking that. The ripcord pull sequence I was trained on (counting to 5):
1 (wave 2 (reach) 3 (pull) 4 (check) 5 (check)
I'm going to start adding the 'check, check' to my EPs that I go over on the ride up. And Tom makes some excellent points re: it being a 'lost skill'...we're coming across a lot of those these days, eh? (Spotting...?)
One question: given that stability is a key component to pilot chute hesitation, does it not seem like this discussion thread is somewhat more applicable to experienced jumpers in total malfunction situations? If I'm an AFF-1 student going through a Cypres fire at 750 feet, I'm more likely to be a bit unstable already than someone with 4000 jumps in the same scenario, right? (Although students *can* be stable...and the experienced jumper might be struggling like hell at 750 feet. But still.)
OTOH, if I'm hanging under a reserve and arch as I pull silver, I won't likely be completely belly-to-earth before my reserve pin has been pulled, will I? Won't it take a couple of seconds for the arch to affect my head-up orientation?
Just curious...
LouDiamond (D 25931)
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May 17, 2009, 7:42 PM
Post #24 of 37
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The thing to keep in mind is that PC hesitations can and do happen with non spring loaded PCs too(although less frequent than with spring loaded PCs). So the simple act of looking over ones shoulder after deployment, be it a main or reserve deployment, can alleviate hesitations in most cases. As was stated, this is more of a training issue for those who have never used or been exposed to spring loaded PCs or those who have used spring loaded PCs but have simply forgotten or stopped doing it.
What it comes down to though, is that ripcord deployment is a SKILL, that has to be learned and mastered, like any other skill.
So is hand deployment. Think of a lazy throw for instance.
Quote:
...which is why I think there needs to be more debate over whether "pull silver and arch" should be trained into the EP's.
AFAIK, while reserve procedures in the Nethelands are taught single handed at some DZ's and double handed at others, both procedures do teach students to arch after pulling the reserve.
Quote:
the simple act of looking over ones shoulder after deployment, be it a main or reserve deployment, can alleviate hesitations in most cases. As was stated, this is more of a training issue for those who have never used or been exposed to spring loaded PCs or those who have used spring loaded PCs but have simply forgotten or stopped doing it.
While I completely agree, I remember that when i had my first PC-hesitation (springloaded pilotchute main) I was checking over my shoulder automatically:
1001 - 1002 - 1003 - 1000WTF??
Edited to emphasise that my hesitation was on a main, not reserve.
(This post was edited by Baksteen on May 18, 2009, 4:57 AM)
Darth drop test #3.jpg
But most of my jumps are FF jumps and i think with the higher speeds i have a better chance of being knocked out. But i only jump in groups with people i trust and if im jumping with a newer jumper or someone i dont know or someone else can not tell me how good the are then i will do a solo with them and trust that i can get out of there way if need be. 
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