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JohnSherman

Should the AAD activation altitude be raised to 1250 feet?

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At the 2011 PIA Symposium, in an interview with Douglas Spotted Eagle, UPT’s Bill Booth, http://www.youtube.com/user/VASSTTraining?blend=12&ob=5#p/u/30/tQuJr5wuvSw recommended raising the deployment altitude by 500 feet in reaction to 9 fatalities (at that time), that had occurred after an “AAD” activation at 750+/- feet. This was a tacit admission that some of his equipment might not be able to deploy a reserve within the required 300 feet, as some of the failures were on equipment of his manufacture. A seven-hundred-fifty foot activation altitude provides a safety margin of 250% over the TSO requirement of 300 feet for a reserve parachute to open. Booth’s recommendation would give a safety margin of 400%. According to sources, Robert Feldman, Attorney at Law (who does legal work for UPT & USPA), will make this proposal at the August PIA meeting.

Do you believe that the 50 year old activation/deployment altitude standards should be changed or not, and why? Please vote in the pole and make you comments on the thread.

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Hi John,

At 73% for #2, you're getting a lot of support.

RE: 50 year old activation/deployment altitude

All Sentinels, that I ever knew of, were programmed to fire at 1,000 ft and they could not be adjusted, unless you zero'd them at some altitude while in the airplane.

JerryBaumchen

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It seems like a good idea on the face of it.

But then another question comes to mind: "How many people would die from two-canopy-out situations as a result of an raised reserve AAD deployment altitude?" Let's say this change could have saved those nine lives, But then how many other people might have died if their reserves had deployed at 1250'? I don't know what that number is, and I don't think anyone keeps any such statistics. Certainly there are a number of people who screw up and go that low before deploying their main, or ride snivels that low. And then of all those people, how many of them would be killed by something like a downplane or a main-reserve entanglement, because the reserve deployed alongside their main?

By way of example, let's presume that we raise the AAD activation altitude to 2,000'. Obviously, there would be chaos in the skies, and lots of problems created. So some altitude would have to be determined between 750' and 2000', where the greatest life-saving good would be done, while at the same time creating the least amount of life-threatening harm. What that number is, I don't know. But the higher the AAD altitude, the more likely it will be to cause other kinds of problems.

I wouldn't want to just trade one set of types of deaths for another type. And without knowing what those other statistics are, I'm going to decline to vote. I just don't know what's best...

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I voted for "No, The manufacturers should fix their problems & meet the requirements of the TSO"
No AAD should compensate the poor rig design....Period.
If you gonna pay 2K + dollars for a H&C, the rig MUST be AAD activation friendly.

Blue skies, skydive hard and DON"T wait for your AAD to save your A$$
"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

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At the 2011 PIA Symposium, in an interview with Douglas Spotted Eagle, UPT’s Bill Booth, http://www.youtube.com/user/VASSTTraining?blend=12&ob=5#p/u/30/tQuJr5wuvSw recommended raising the deployment altitude by 500 feet in reaction to 9 fatalities (at that time), that had occurred after an “AAD” activation at 750+/- feet. This was a tacit admission that some of his equipment might not be able to deploy a reserve within the required 300 feet, as some of the failures were on equipment of his manufacture. A seven-hundred-fifty foot activation altitude provides a safety margin of 250% over the TSO requirement of 300 feet for a reserve parachute to open. Booth’s recommendation would give a safety margin of 400%. According to sources, Robert Feldman, Attorney at Law (who does legal work for UPT & USPA), will make this proposal at the August PIA meeting.

Do you believe that the 50 year old activation/deployment altitude standards should be changed or not, and why? Please vote in the pole and make you comments on the thread.



I take from the tone here that you are against such changes John, if so why..I respect your opinion and I'm sure you have reasons/thoughts on the subject I haven't considered.

IMO, there are a number of factors that effect the opening sequence and may possibly be circumvented with some additional altitude...body position etc.

I personally don't use an AAD, so I haven't given great thought toward the activation altitude question...your input is always appreciated.










~ If you choke a Smurf, what color does it turn? ~

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And without knowing what those other statistics are, I'm going to decline to vote. I don't know what's best...



I didn't answer either. I don't have enough knowledge about whether or not any changes to modern gear have made the gear statistically more reliable enough to justify changing the TSO requirements and raise the activation altitude.
Owned by Remi #?

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We have just begun a conversation to raise the deployment altitudes across the board by 500 feet. I have no objection to doing that, if it can be proven it will work. Root cause definition and backup data must be aquired and evaluated before such a move is made. As a parachute designer I understand the root cause of most of the failures and they do vary slightly from system to system. I do not believe that raising the altitude for AAD firing to 1250 feet will cause a reserve deployment bag, which takes 75 pounds to extract from its container, will find more drag for its undersized or otherwise inadequate pilot chute to generate more force. Nor do I believe that a pilot chute with a drag coefficient of .33 will increase its drag to a level necessary to perform its task. Nor do I believe that rigs designed with over applied cantilever flaps which are designed to reduce pin pull force will find a way to open, enough to allow the pilot chute out into the air stream in a extra 500 feet. Someone even said that this feature was intentional to prevent a “2 out” situation.

These conditions and others that are found singularly or in combination create a mutually dependent failure mode that prevents a container of this type from being reliable enough for personnel use.

I have a plan of corrective action written and I will post it very soon. I sent a copy to Cliff Smucker over a mounth ago and now he won't return my e-mails or phone calls. Oh! the politics of parachutesB|

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1) I don't jump AAD's in sport rigs so I don't have a personal stake in this.

2) I do jump AAD's in Tandem rigs and I am comfortable with the margins currently used for them.

3) I think I am aware of some of the "problems" with AAD deployments, and since they are generated from IMO style rather than safety motivated changes to H/C & Reserve combinations I think that is where attentions should be focused.

4) I am not in favor of increasing the activation altitude of AAD's across the board.

5) Every AAD user has the option of increasing their own AAD's activation altitude at any time prior to donning the equipment.
----------------------------------------------
You're not as good as you think you are. Seriously.

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Big issues here are skydivers' understanding of the 300 ft thing, and the actual distance required to open a reserve.

As for the "opens in 300 ft" thing, skydivers sort of know that as the requirement for reserves. But when one looks at the certification regs, it isn't quite as clear cut. (John Sherman of course understands this.)

When testing reserves for opening after a cutaway, the jumper can be flying at speed under a main canopy, so it isn't starting with a vertical direction of motion, nor is it done from zero initial speed.

And the high speed tests don't have to be done vertically -- typically it is a horizontal test from an aircraft, making it much easier to stay within a 300 ft limit.

There's also a 3 second opening limit, so that helps restrict things a bit. (If one were doing 174 fps straight down, that would give 522 ft max, but that's only for an unrealistic full speed plus instant stop at the end, so a lower distance would be more typical.)

There's a lot more to the regs but I think this is a reasonable simplification. The times and distances were I believe similar in earlier certification standards but I'm not sure off hand.

Also, in certification tests I am a little suspicious about the definition of "functionally open". While that includes total speed and rate of descent limits, I wonder how accurately these are measured, whether in actual tests the clock has ever been stopped while the canopy is still mushing or diving, not yet in steady state flight, despite having full inflation and slider down.

Nor do the tests have to reflect any sort of realistic container configuration, such as tight modern rigs.

From a skydiver's point of view, whether or not it is realistic to have reserves always open within 300 ft, it all seems a big gyp. Now that's only based on skydivers' imperfect understanding of the certification rules, and companies have technically followed all the requirements.

In the end, it really means I'm not quite sure how much distance it takes for reserves to open in realistic situations. Which makes it hard to plan for how high AAD's should fire, even if there is some evidence that altitudes might be bumped up a bit.

An added complication is the whole belly vs back compensation, so you get existing AAD's sometimes firing at say 1100' if someone is finshing snivelling down through that altitude.

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Correct me if I’m wrong – despite all the negative publicity that ARGUS has received – (some of it because of misinformation here) the recent fatalities were NOT the result of failure on the part of the AAD to “fire”. The fatalities were the direct result of the failure of the container to get the reserve out and deployed in time. Did you hear that? Even if your AAD were to fire at 2,000 ft - if the container doesn’t meet the TSO - your reserve may not open in time. All that extra 1250 ft and maybe 7 - 8 seconds will give you is more time to soil yourself when you realize you’re SOL – but hey, at least your AAD fired for whatever that’s worth.

NO – the altitude shouldn’t be raised – the manufacturers should be REQUIRED to fix their problems & meet the requirements of the TSO, otherwise I believe the word would be “liable!”

Remember, when manufacturers have the control of the information it can be bent however they want … where’s an independent testing lab when you need it?

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Nor do the tests have to reflect any sort of realistic container configuration, such as tight modern rigs.







I always wondered about that...how does it work stuffed tight with a total on the bottom tray.










~ If you choke a Smurf, what color does it turn? ~

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Firstly it doesn't take much of a pilot chute hesitation before a substantial amount of 750 foot is used up.

But we already have a fairly substantial quantity of two out situations where people open low.

There was a discussion in the incidents thread about people who want to open higher due to a long spot and the dangers that it can present. So raising the AAD firing threshold would require the opening altitudes be raised for everyone to avoid that creating a new risk. That is fine for everyone jumping at turbine dz's but what about people at Cessna dz's? Suddenly the ability to do a 4 way out of a cessna becomes nigh on impossible.

My personal view is that AADs should remain at 750ft. Possibly student AADs could fire at the 500 foot higher margin as they already open higher (A license and students are supposed to be pack open at 3k).
Experienced jumper - someone who has made mistakes more often than I have and lived.

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I would agree with bill booth and raise the firing altitude of an aad. I would like to see it said at a 1000feet minimum. I dont think that there is a problem with the gear manufactoring. I have had 38 cut aways in my time and never had an issue with a reserve. I think it comes down to human error in most of those cases and not reacting to a situation in a timely manner. With modern canopys especially high performance canopys and eliptical canopys a jumper can loose a lot of height very fast. Some also subject a jumper a lot higher g force and takes them a fraction longer to get to the handles and pull them. Also a better chance thst a jumper will be a lot more unstable after a cutaway from an eliptical canopy and they wait a couple extra sec to get stable. Also i see a lot of gear that have there rsl removed. That also could save a fex extra lives.
Also it could save a jumper, if he has a couple extra sec to clear a reserve bridle if he has somehow snagged it around himself after a cutaway.
I think raising the firing height would be beneficial. And i also agree with john sherman that all main deployment heights should be raised by 500feet

my 2 cent worth

rodger

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As an old timer who started on rounds, I routinely opened at 2,000 -2,500 feet. Back in the sport after a long layoff, and noting the nicely sequenced slow opening of today's mains, which use up more airspace. I upped my minimum to 3,000-3,500 feet, except on big-ways where you may have to open lower. I did this before I saw Booth's comments, which seemed to be logical. If you do this, you needn't worry whether your Cypres or Vigil is set to fire at 750 or a 1000 -- assuming you do not stay with a malfunction beyond the normally acceptable time frame.
SCR-442, SCS-202, CCR-870, SOS-1353

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I voted no. I raised my personal minimum deployment altitude to 2500 feet (from 2k) when I got a Cypres because I do not want to fly both my canopies at the same time. Bump the activation altitude another 500 feet and my personal minimum deployment altitude will have to go to 3k. Which doesn't leave a whole lot of freefall time if I'm jumping a Cessna, does it?

But it would be way cheaper for certain manufacturers than having to redesign and then test to the latest TSO (instead of the one from 30 years ago) a container that works like containers are supposed to. Maximize profit, even if it comprises safety, that's the American way.

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I voted no.
The H/C manufacturers justn need to get with the existing limits and make it happen.

@ JP (diablopilot) could you link the chop that you recently had here (like in the last week or so).

Watch the reserve pilot chute being dragged momentarily......... probably lost 30-50 feet as a big guess.

To be clear, I do not even know what H/C system you have, so I am not "Witch Hunting" here.

BS,
MEL
Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

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....failure of the container to get the reserve out and deployed in time.....
NO – the altitude shouldn’t be raised – the manufacturers should be REQUIRED to fix their problems & meet the requirements of the TSO,



That's why I voted no.
My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

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That is fine for everyone jumping at turbine dz's but what about people at Cessna dz's? Suddenly the ability to do a 4 way out of a cessna becomes nigh on impossible.



Huh? Our Cessna (the 182, not the Caravan) usually hits jumprun at about 10K. How is raising AAD activation altitude 500 feet going to make 4 way impossible?

That aside: My outright admiration of Bill Booth makes me want to trust his opinion.

My outright admiration for the input given here frompeople who disagree with Bill Booth make me want to trust their opinions.

I'm not going to answer. I'm too ignorant.
Owned by Remi #?

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I voted no, but I must say that you have worded the question in such a way as to get the answer you seem to be seeking. Are you a part time politician?

Ken gowler
Always remember the brave children who died defending your right to bear arms. Freedom is not free.

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I have watched Bill Booth's comments several times since he made them at PIA and I had the distinct impression from day one that he is genuinely trying to prevent avoidable fatalities where just a little more time / altitude means survival.



If the prevention of fatalities is the case, he should allow any/all manufacturers use the Skyhook free of charge. It sure seems to be marketed as a safety device that could prevent fatalities. I am not saying that he is not trying to prevent fatalities but it is hard to play that card when you are trying to turn a profit with this safety device.

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There is a certain risk of two outs.

I think the manufactures of AADs could build a data collection terminal - even if it is a 2nd AAD who's cutter does not cut anything, and "try" the new altitude settings on 500 jumpers to see if everyday skydivers scare their AADs to the point that the possible two-out risks outweigh the safety added by increasing the AAD altitude.

Honestly - I see the big way skydivers taking it lower than freefliers and other smaller groups, so perhaps this should be looked at too.

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