Should the AAD activation altitude be raised to 1250 feet?

[councilman24 36]

First all of my opinions are my own and do not represent those of the PIA Rigging Committee or PIA.

Your poll presupposes there are rigs on the market that do not meet the TSO testing standards that apply, AND that 300' is the standard. TSO testing involves minimal testing of a few items and combination of items. It does not require testing of every item and set of combined/assembled items packed by each and every rigger. I think we are all intelligent enough to know that individual sets of H/C and canopies, packed by individual riggers may very well not meet the TSO standards.

While 300 feet CAN be applied under TSO C23d, the common standard for all three TSO's currently represented is 3 seconds or more. Four with twisted lines. Many of us routinely forget this fact. (For those that don't know all three currently used TSO testing standards are available in the FAA Rigger Handbook.) Using 300' gives breakaway openings extra time (total app. 4.4 seconds) while still requiring a reasonable altitude loss. 3 seconds at 120 mph is 528 feet! 160 mph (head down) 704'. It might be suggested that it's surprising we don't have more reserves not opening with in the app. 750' supplied by an AAD activation.

Is it reasonable to expect that individual examples of rigs that have met TSO testing, assembled and packed by individual riggers may take more than 3 seconds or 300' to open? Sure. This includes all manufacturers including Jump Shack/Parachute Labs. (personal experience)

What makes these rigs take longer than 3 seconds? We don't know. My PERSONAL opinion is that the design of some rigs, including the size of canopies suggested for an individual container size AND the size of canopies an individual rigger may choose to put in a container, contribute, and especially with the main full.

So the poll without bias might say 'Given currently used TSO performance standards, yes the activation altitude be raised from 750'.' or 'No, the 750' activation altitude is sufficient.' If we keep 750', given that all rigs have passed TSO testing standard applicable but individual sets of equipment with field rigging may exceed those standards, I expect that some people that would have bounced without an AAD will still bounce in spite of the AAD trying to save them.

IF you believe that all rigs/canopies should be designed to meet the TSO standard no matter what canopy is crammed in them and what rig a canopy is crammed into, with whatever variations in rigging exist, I expect that ALL current designs would disappear Wonderhogs and 1982 Northern Lites would return.

I think that once we apply the 3 (or 4 second for twisted lines) standard to todays freefall speeds AND the variation in container/canopy combinations and rigging that perhaps something somewhat higher than 750' is reasonable. But 750' has been HIGHLY effective at saving skydivers. Including head downers.

At the time of introduction of the CYPRES resistance to AAD's was largely fear of inadvertant (or justified) firing and two out. I'd have to ask Helmut if skydiver acceptance was a consideration in setting 750' (app. 4 seconds or less off the dirt) as a resonable last chance. I believe that is the case.

The willingness to accept (demand?) a higher activation altitude may be a result of changes in main canopy opening characteristics raising pack opening altitudes and the newer wide spread personal desire to only jump with an AAD.

I believe John refers to the BSR pack opening requirements in his last line. Minimum pack opening for most experienced jumpers at 2000'. Personally, for the equipment I jump, I'm comfortable getting out of an airplane at 2000'. I might not be so comfortable getting out of a zero airspeed balloon at 2000'. Freefall opening at 2000' is less than I'm comfortable with mainly do to high speed malfunction reaction time available. But I jump canopies with old style opening characteristics. Meaning they don't streamer for 800' before finally deciding to open. IF I jumped a canopy with openings of 700 to 1000' I would raise my own minimum altitude. Should they be changed? No. I believe they are reasonable for some equipment still in use and thus should be available under the BSR's for individual choice.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[piisfish 135]

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I mostly do tandems these days.but i adjust my speed cypres 250 higher at the start of the day when i doo aff jumps.

do you readjust after each jump ? or is there a new "offset" function I wasn't aware of ?

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[irishrigger 31]

You learn something new every day. I was under the impression that once you reset the cypres 250 higher is stays like that until the unit switches off.
I have just received a private email letting me know that this is not correct! it reset itself after that every jump apparently!
I guess i should have read the manual more in detail.
You learn something new everday!

Thanks and cherrio
stay safe and blue skies
rodger

[masterrigger1 2]

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TSO testing involves minimal testing of a few items and combination of items. It does not require testing of every item

This is exactly why there should be required TSO procedures and standards in place for AAD openings altitudes somewhere in the TSO.

PIA should be focused more the causes of the numerous fatalites related to non-functional systems rather than issues like say the lead seal project IMHO.

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While 300 feet CAN be applied under TSO C23d, the common standard for all three TSO's currently represented is 3 seconds or more.

Exactly. This is but one of the problems.

AAD manufacturers figure the sequencing with altidude in mind, not seconds.
Depending on the scenario, the values can and will be different.
Remember altitude is always just that; altitude, and that is what keeps us alive.

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I think we are all intelligent enough to know that individual sets of H/C and canopies, packed by individual riggers may very well not meet the TSO standards.

I would have a hard time believing that, if different riggers packed the same parachute system in accordance with the H/C manual, there would be much of a difference in altitude between different riggers.

What I do know that makes more of a difference is what size canopy is packed into what brand of H/C.


Cheers,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[councilman24 36]

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I think we are all intelligent enough to know that individual sets of H/C and canopies, packed by individual riggers may very well not meet the TSO standards.

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I would have a hard time believing that, if different riggers packed the same parachute system in accordance with the H/C manual, there would be much of a difference in altitude between different riggers.

What I do know that makes more of a difference is what size canopy is packed into what brand of H/C.

The statement above was ment to include variations in each set of gear, canopy size versus container size, etc AND rigging techniques. We have all learned how closing loops that are too long may inhibit pack opening. I met a rigger in Feb. who checked each pack job by pulling it slowly. He routinely got high pull forces that probably were an artifact of the way he tested it, and would then lengthen the loop.

I didn't mean that rigs packed by good riggers following the manuf. instructions (which at times are difficient in information or guidance) with appropriate sized canopies would routinely not meet the TSO criteria. But they might. I believe we can expect variations in performance. My guess is that most open faster than 3 seconds so that variation might for the most part be incompassed within the TSO standard.

PIA, in their advisory last year, asked for information that might help identify the causes of those incidents where AAD's fired and canopies failed to open in time. To date we have received 4, maybe 5, anomoly reports. Without information from the field we have little to work with. PIA is very concerned about this. Technical committee members are developing testing protocols that may help identify extraction issues.

MEL, now that your a member PIA is YOU! I'll see you in St. Louis in August, right?

For all... Most involved in the Parachute certification Standards Committe of PIA expect AAD's to be included in the next TSO standard. The PIA performance standard intended to be the standard for TSO C23f (e was already issued and recinded) doesn't include them. Why? Many reasons. Development of the PIA standard was begun in 1992 or so. About the time modern AAD's were introduced. AAD's are not certified devices (by the FAA) in the U.S. They weren't even mentioned in the U.S. regulations until 2001. The PIA standard was essential finished a number of years ago, before these concerns surfaced. That was after 10 to 15 years of often contencious debate and sometimes very slow progress. Adding AAD's to the end of the process in the last two years would have extended the deveopment of the PIA standard my at least a couple of years. The way to include a non-certified accessory into a TSO performance standard isn't clear. That's not to say that it shouldn't be included, and at least one AAD manufacturer has publicly asked for AAD's to be included.

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While 300 feet CAN be applied under TSO C23d, the common standard for all three TSO's currently represented is 3 seconds or more.

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Exactly. This is but one of the problems.

AAD manufacturers figure the sequencing with altidude in mind, not seconds.
Depending on the scenario, the values can and will be different.
Remember altitude is always just that; altitude, and that is what keeps us alive.

As evidenced by the original post and many of the replys many of us believe that 300' is the maximum allowed distance for a reserve to open under the current and previous TSO standards. It isn't. Three SECONDS is the shortest maximum time allowed and it can be higher. As I previously stated this can translate to much farther than 300'.

Is 750' high enough given the 3 second standard? Maybe not. But it has worked amazingly well. And individual jumpers will have different comfort levels and needs. Deciding on a different standard height, AND having it accepted by the manufacturers, is a long discussion.

As always, opinions are mine, not PIA's unless specifically stated as a PIA position.

The PIA proposed certification standard for use in TSO C23f is available at http://www.pia.com/piapubs/TSDocuments/TS-135v1.4.pdf It may be altered by the FAA when the TSO document is issued.

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

[matthewcline 0]

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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.

What Bill has asked for is near free. $5 a Rig is what I was told. Since he would now be added to another companies lawsuit (if some thing happened) he would put this in the legal defense fund at UPT.

Matt

An Instructors first concern is student safety.
So, start being safe, first!!!

[Beatnik 2]

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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.

What Bill has asked for is near free. $5 a Rig is what I was told. Since he would now be added to another companies lawsuit (if some thing happened) he would put this in the legal defense fund at UPT.

Matt

Near free and free are still different. If you look at some of the other MARDs out there, they are being marketed for free because they believe that it will beneficial. Charging money for the reason you gave doesn't justify the position was given earlier. If people really wanted to tie UPT in with lawsuits they could since every sport rig out there right now uses the 3-ring release. Plus if there is no lawsuit, will the money go back to the companies? I think not and it will come back as profit. I am sorry but given the information I have doubt that the interest is in only with the safety of the jumpers. This is just my opinion on this and that in itself doesn't make it true or not true.

[DaVinciflies 0]

I voted yes based on the following - I would rather land with two out than nothing out.

Having said that I don't ever intend to be in freefall at 1250 or 750 feet. My personal hard-deck is 2,000 feet. The only time this might apply to me is if I am unconscious and then I want the highest possible chance that an AAD fire will result in a functional reserve.

[KellyF 16]

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What Bill has asked for is near free. $5 a Rig is what I was told. Since he would now be added to another companies lawsuit (if some thing happened) he would put this in the legal defense fund at UPT.

It's $125, IIRC. $100 for the patent royalty and $25 for the hook and misc. parts, as I remember. Even if it were free, you wouldn't find it on an Infinity since it can complicate things (relative to the majority of rigs that are currently in the field) should you scare your AAD during main deployment. This creates different EP's for different brands of rigs, which I think is a step backward for the sport.

To get completely back on topic, I could see raising the AAD firing altitude to 1000', but I think 1250' is a bit excessive.

[JohnSherman 1]

Proposed Solution for Reserve Extraction Issue

First we must acknowledge there are bad rigs in the field and that most of the problems occur with the main closed. A MARD won't help if the main is closed.

The purposes of this effort are to surgically and methodically weed out those rigs and to develop a certification and testing procedure to prevent future occurrence.

For the purpose of this discussion let us think about a horizontal plane with the wearer lying face down along that plane. Think of a protractor on the back of the jumper with zero degrees at the head, which is to the right, and one eighty at the feet, which is to the left. We can see that the first 20 degrees and the last 20 degrees are for all intents and purposes unusable. For clarity we acknowledge 90 degrees as straight up and perpendicular to the jumpers back.

The field correction portion of this procedure must include a test for bag extraction. This test must be simple and indicative of the overall extraction effort. It must be made during the time when the rigger first opens the container by pulling the ripcord. It must be made with the main container packed and fully closed. It might be recommended that the owner don the rig and lay on their stomach for the test. They should pull the ripcord and the rigger could then, after pilot chute launch, test the extraction.

The direction of the pull on the bridle for the extraction test should be 45 degrees up toward the head from the perpendicular or at 45 degrees on the protractor. Assuming the bridle is located at the top of the bag, which is at the top of the container, a pull in this direction would cause the top of the bag to lift and begin rotation as it is extracted. Selecting this direction avoids the airing of the issue of a difficult 20-degree pull or the seemingly impossible 160-degree pull direction. I have seen extremely difficult pulls on both directions but I believe the recommended direction will be the lowest pull we could expect to encounter while still being indicative of the overall requirements. It is the direction most commonly seen during actual deployments. We only get one bit at this apple ‘cause we can’t put all the work on the rigger that needs to be done. We really can’t ask them to do more.

The force extraction limits must have a base line force described by rule. I would begin by recommending the weight of the bag and canopy plus ten (10%) percent. This percent overage is negotiable from my perspective and could go up quite a bit depending upon what others want. Certainly something must be added to allow for some friction. I could handle whatever as long as it didn’t go over two times (200%).

Rules about what to do as a result of the test: The rigger is there to re-certify the rig. If their initial extraction test exceeds the base line limit, described above, then the rigger must consult the manufacturers instructions to see what limit the manufacturer has allowed on this container which was based upon the drag capability of the pilot chute.
If the test results fall within the recommendations of the manufacturer then the rigger may proceed. If the initial inspection test procedure results fall within the baseline requirements then the after pack job test may be waived. If the manufacturers’ specification allow a greater than base line force then the rigger must, after closing the rig and before sealing it, pull the ripcord and repeat the initial test to assure the pack job is good enough to meet the manufacturers extraction requirements. If within compliance, the rig may then be reclosed with minimum disturbance or relocation of the bag and canopy. All other requirements being met the rig may be sealed.

Certification and testing: The manufacturer must develop and publish the allowable extraction force for their container, as above. They must also publish the pilot chute requirements for that container. The pilot chute requirement would be specified as “Effective size” or physical size times the drag coefficient (Cd*So). This information would be published in the owners’ manual. It would appear as “Allowable Extraction force = xx“ and “Pilot chute effective size requirement = xx inches/feet”. Even if the containers extraction force doesn’t exceed the base line a minimum effective size of pilot chute must be specified. I really don’t think it matters how the manufacturer derives the maximum allowable extraction force. What really matters is the drag capability of the pilot chute. Here I believe is the difficult swallow for the manufacturers. All pilot chutes must be placarded with “Effective Size” (Cd*So) or they could be placarded with physical size and Drag coefficient, whatever. This identification of the capability of the pilot chute is necessary as they are components that could potentially be interchanged from rig to rig. With the containers marked with Max effort and pilot chute size requirements and the pilot chute marked with capability the assembling rigger may choose within those numbers.

Lets face it, the manufacturers are going to have to test their pilot chutes and develop the numbers so as to placard them. I believe that the PIA could set up a deal with some school like Embry Riddle to test pilot chutes in the wind tunnel for a fee. I don’t care how they test them but the FAA ACO might… or not!

Initially, in the field, only the extraction test may be made, as our pilot chutes aren’t identified with the “Effective Size”. As a policy I believe the PIA could require it’s members to publish the required data for their pilot chutes within an agreed upon time frame. “I know, how can they publish the allowable extraction force before they know the drag of their pilot chute”? They can’t, but I won’t tell.

[matthewcline 0]

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What Bill has asked for is near free. $5 a Rig is what I was told. Since he would now be added to another companies lawsuit (if some thing happened) he would put this in the legal defense fund at UPT.

It's $125, IIRC. $100 for the patent royalty and $25 for the hook and misc. parts, as I remember. Even if it were free, you wouldn't find it on an Infinity since it can complicate things (relative to the majority of rigs that are currently in the field) should you scare your AAD during main deployment. This creates different EP's for different brands of rigs, which I think is a step backward for the sport.

To get completely back on topic, I could see raising the AAD firing altitude to 1000', but I think 1250' is a bit excessive.

Still not a bad price as it comes as a kit.

The Skyhook doesn't effect the Industry Standards for EP's they are the same, packing is a tad bit more complicated though.

I think the Rigs and Reserves need top meet the 300' opening standard. ADD's need not be raised as an across the board rule though.

Matt

An Instructors first concern is student safety.
So, start being safe, first!!!

[BKR 0]

Hi John and All,

AAD hits the market in 92 and all testings were done with rigs from this age. Since rigs design have changed and most of them have never been tested with their new design using AAD's and even not using them, this went to problem all knows some years ago. Most of the actual reserve containers are not adapted to meet the 300 ft requirement of the TSO.
This is my opinion and I agree with John and Kelly, not on all but on most of the points.

Jérôme Bunker
Basik Air Concept
www.basik.fr
http://www.facebook.com/pages/Le-Luc-France/BASIK-AIR-CONCEPT/172133350468

[woppyvac 0]

I noticed a lot of the folks who have responded thus far are D licensed. Personally - I'm only 70 jumps into this - but I have no quarrel with AAD's raising their firing altitude. In my mind I'm already testing the gods with each jump and with that train of thought deploy at 3,000ft - Religiously. The closest I've come to the 1,250ft mark happened due to a snivel that lasted longer than any other I've experienced and even then I about 1,500-600 feet. Like Booth said at PIA 2011 - I sweet bullets after 3,000ft. And at my level of expertise I'd much rather have to combat a two out than pray for no delay with my AAD.

Woot Woot!

[airdvr 197]

All these safety devices are making skydiving way too risky.

Please don't dent the planet.

Destinations by Roxanne

[KellyF 16]

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The Skyhook doesn't effect the Industry Standards for EP's they are the same, packing is a tad bit more complicated though.

If you're referring to decision and execution altitudes, we can agree, but when the smelly stuff hits the fan and 1/2 your parachute goes away at 250' (as happened in Chicago not long ago), the standard EP is NOT to pull the cutaway handle. Typically in a situation like that a jumper will want to get more material above their head. Simply pulling the reserve to get more fabric out may very well do nothing at all except launch the reserve PC on a Skyhook equipped rig, as there likely won't be enough airspeed to break the seal thread holding the PC (via the bridle) to the RSL. So this jumper had two options- ride in what he had, or get rid rid of it entirely and hope that he got more out before impact. Luckily, pulling the cutaway handle mostly worked out for him.

The same type of thing can happen if your AAD fires at the tail end of your main deployment- PC towing behind the jumper. This is being touted as a "feature" because it "prevents a two out scenario", but it doesn't necessarily prevent it unless the jumper reels in and controls the PC, which I think is silly if you just opened ~750'- your attention should be focused elsewhere.

Thats enough thread jacking for me.

[ruthers 0]

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The force extraction limits must have a base line force described by rule. I would begin by recommending the weight of the bag and canopy plus ten (10%) percent. This percent overage is negotiable from my perspective and could go up quite a bit depending upon what others want. Certainly something must be added to allow for some friction. I could handle whatever as long as it didn’t go over two times (200%).

10% seems like a very stringent requriement. If a PC could only make 10% more than the weight, that would mean that once the bag was free of the container, it would only accelerate away from the jumper at 1/10th of a G.

If the distance to line stretch is say 3.5m, and you want to achieve that distance in say 1 second (is that reasonable/too short, too long? How much of the TSO 3 seconds is typically taken to go from a taut PC bridle to full line stretch? ), the bag needs to accelerate with respect to the jumper at about 0.7G. So the PC would need to be pulling the weight of the bagged canopy plus 70% to achieve this.

Doesn't that mean that any PC able to pull enough to acclerate a bag fast enough to get it it line stretch in a reasonable amount of time should easily extract a bag even with bag weight plus friction of say 50%-70%?

Or did I misunderstand John's intent with the test?

Cheers,
Hamish

[pchapman 261]

Ruthers:
John S. was talking about the force to pull the bag out of the container, how tight the container can be, rather than the other issue of the force that the pilot chute can apply.

But yes there is the issue of how good a pilot chute one needs to have. Usually we make do with the same PC whether it is a student (or tandem reserve) or a PD 99 reserve.

[JohnSherman 1]

Thanks Peter, you are right on.
It really doesn't matter how much extraction force is required if the pilot cute will handle it. When one of the manufacturers told a rigger that 75 pounds of extraction was acceptable. I noted that it would take a 25 foot pilot chute to do the job. That is If the pilot chute had a Cd of .65 or better.
Pilot chutes must be qualified and marked with their effective size (Cd*So).
We have 2 options on our reserve pilot chutes, Standard and SRP. The standard is 36 inches and the SRP is 30 inches. Both have a Cd of .84

[sundevil777 93]

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When one of the manufacturers told a rigger that 75 pounds of extraction was acceptable. I noted that it would take a 25 foot pilot chute to do the job. That is If the pilot chute had a Cd of .65 or better.

Which mfg?

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[ruthers 0]

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Thanks Peter, you are right on.
It really doesn't matter how much extraction force is required if the pilot cute will handle it. When one of the manufacturers told a rigger that 75 pounds of extraction was acceptable. I noted that it would take a 25 foot pilot chute to do the job. That is If the pilot chute had a Cd of .65 or better.
Pilot chutes must be qualified and marked with their effective size (Cd*So).
We have 2 options on our reserve pilot chutes, Standard and SRP. The standard is 36 inches and the SRP is 30 inches. Both have a Cd of .84

Do you mean that to achieve 75 pounds of extraction force, with a Cd of 0.65, a PC with 25 square feet of surface area? What airspeed and density was assumed for this calculation?

[JohnSherman 1]

At 2000 feet, 1 second after a cutaway you have a decent rate of 36FPS (20FPS on initial descending canopy plus the additional 16 feet of the first second acceleration. The Rho for that altitude is .002242 Slugs, Apply (½ Rho V^2) the formula for Q, you have about 1.5 pounds per sq. ft. (1.5Q). With a Cd=.65 and an So=25 sq. ft. you get 16.25 Effective sq. ft. At his point in time you have 24.4 pounds of drag. If you need 75 pounds you could wait a second or so. Drag= Cd*So*Q

[ruthers 0]

Thanks John.

[Andy9o8 0]

I'd raise it to 1,000 feet (or 300 meters). As a jumper, that would work for me. Not having a stake in the liability balance, that seems to me to be a reasonable balance of all considerations.

[aerorigging 6]

Noooo!!, because then you will need to set up higuer the main opening altitude and the airplane jumping altitude, and the jump price increase, or you think people will short their jumps because the manufacturers make super tight containers, and defective gear.
I vote also to not use AAD and play more responsibility skydiving choosing your load partners, opening at the right altitude, wearing the correct reserve size for the container we use, etc, etc.

Nico

Nicolas Lopez
Master Rigger
Aerorigging Parachute Loft

[Trae 1]

in reply to "I vote also to not use AAD and play more responsibility skydiving choosing your load partners, opening at the right altitude, wearing the correct reserve size for the container we use, etc, etc. "
..........................

Hopefully the AAD crowd do this as well...praps not for some.

At some point, especially if reserve activation altitude is increased, it might seem more appropriate to put the AAD on the main.

Then the activation altitude would be raised up to main opening heights. In a real emergency all that extra height could be very handy.

If people are genuinly concerned with getting unconscious in freefall, it would seem more logical to provide themselves with a slow docile AAD'd 7 cell non-snivelling main (ie low aspect ratio, lightly loaded canopy) that will let them down relatively safely while unconscious .

But by all means, raise the activation altitude for these people , if you feel like you need an AAD to survive or CYA, then you need extra altitude even more.