Reliability of AAD's vs reserves

[riggerrob 558]

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I have also seen students cut away from line twists that were fixable and we tell them if they are not sure cut it away. But what if they cut away something that is landable and get into more trouble?

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AADs are more reliable than students.

... I avoid mentioning AADs during the first jump course as I do not want students to depend upon AADs. If they are not confident that they can respond correctly to common malfunctions, they should not jump.
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That is the gamble, right? But the odds strongly favor that choice over holding onto a marginal main.

But I know exactly what you mean - when you cutaway, you're down to the last chance. So long as you're under the main, you have it plus the last chance. Or at least until somewhere around the 1000-1500range. I think the students are told to cutaway immediately because the risk of waiting too long poses a greater threat.

I worry that this thinking might keep me holding onto a bad main too long. Until (if) it happens, can't be sure. I just keep the hard deck in mind, and still open a bit high.

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The main reason students are taught to cutaway from naughty mains is to avoid the scenario where they hesitate, mess with a malfunctioning main too long, hesitate, then cutaway, hesitate and pull their reserve ripcord too low.
This disasterous scenario has killed several students.

[JohnMitchell 14]

***Finally, students are taught to lose the canopy if they don't like it. Sure, sometimes they chop a spinner that might've easily been fixed by pulling down once on the toggles.

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We train our students to pull down on the toggles twice with a low speed partial malfunction, then, if neccessary, chop it.

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[tbrown 26]

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***Finally, students are taught to lose the canopy if they don't like it. Sure, sometimes they chop a spinner that might've easily been fixed by pulling down once on the toggles.

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We train our students to pull down on the toggles twice with a low speed partial malfunction, then, if neccessary, chop it.

That's a good thing to be training them for. As with my remark about "3 sec/300 ft" for the TSO opening requirements, I was rather broadly paraphrasing and generalizing. I only mentioned students cutting away a popped toggle because a number of them have written to these Forums and said they had done exactly that and wanted to know "if they did the right thing". Which would appear to make it a real issue, at least at some dropzones. The usual concensus in these Forums has been that if the student is alive and in one piece they did the right thing, but in the future should try pulling down their toggles once or twice.

Anyway, Merry Christmas John AND Sparky, you guys are the best !

Your humble servant.....Professor Gravity !

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[mjosparky 3]

And a Merry Christmas to and your Tom.

Sparky

My idea of a fair fight is clubbing baby seals

[billvon 2,400]

An AAD will always be less reliable than a reserve. A reserve may save your life if it opens correctly; an AAD will only save your life if it fires correctly AND the reserve opens correctly.

>So, my question is, can we teach our students that using a reserve
>is always a safe option?

No. A reserve can malfunction just as a main can, and can have all the same minor problems (line twist etc) that a main can. It is, however, safer than the alternative (landing under a baglock.)

[kelpdiver 2]

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An AAD will always be less reliable than a reserve. A reserve may save your life if it opens correctly; an AAD will only save your life if it fires correctly AND the reserve opens correctly.

That's true if you have an AAD.

If not, a reserve only saves your life if you pull the handle (or cutaway with a working RSL). So then it's a comparison of the reliability of an AAD versus that of a person.

[Reginald 0]

Slight tangent here: My main is unceremoniously stuffed in a bag in 6 minutes. My reserve has every stitch lovingly inspected by a master rigger and is carefully packed and inserted into the container, moreover it is designed to open quickly and reliably (although it doesn’t fly as nice as the main). Both mains and reserves have malfunctions, however, I expect my reserve to be more reliable.

When I first started jumping I worried “if my main has a malfunction why should I expect my reserve to be any more reliable…it can malfunction too.” Well sure it can but if you don’t trust your reserve you might hesitate at the moment of truth. Trust your reserve, which I also think means trust your rigger, which means find a rigger you trust.

I had “reserve reliability fear” until I had a nasty spinning mal and had to chop. The speed and stability of the reserve deployment gave me confidence in the equipment. I no longer have “reserve reliability fear”

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[kallend 1,623]

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An AAD will always be less reliable than a reserve. A reserve may save your life if it opens correctly; an AAD will only save your life if it fires correctly AND the reserve opens correctly.

That's true if you have an AAD.

If not, a reserve only saves your life if you pull the handle (or cutaway with a working RSL). So then it's a comparison of the reliability of an AAD versus that of a person.

And in most cases that person is a person who has just demonstrated their inability to deploy their main in time.

...

The only sure way to survive a canopy collision is not to have one.

[kallend 1,623]

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An AAD will always be less reliable than a reserve. A reserve may save your life if it opens correctly; an AAD will only save your life if it fires correctly AND the reserve opens correctly.

But the reserve can only save your life if it's deployed. You should compare the AAD with the human, not with the reserve.

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The only sure way to survive a canopy collision is not to have one.

[billvon 2,400]

>You should compare the AAD with the human, not with the reserve.

Well, the original question was "should you rely on the AAD more than you rely on the reserve?" If you are indeed relying on the AAD (i.e. just waiting for it to fire) you've already taken the human out of the picture. And if you do that, then waiting for the AAD to fire will always be less reliable than a theoretically perfect human who intentionally deploys the reserve at 750 feet.

If he's not perfect (which is usually the case) then you enter the real world where the _system_ of skydiver, AAD and reserve is more reliable than any two elements considered separately.

[tbrown 26]

When I first started jumping I worried “if my main has a malfunction why should I expect my reserve to be any more reliable…it can malfunction too.”

I had “reserve reliability fear” until I had a nasty spinning mal and had to chop. The speed and stability of the reserve deployment gave me confidence in the equipment. I no longer have “reserve reliability fear”

[billvon 2,400]

>I think cutaway/reserve fear accounts for a lot of low or no cutaways.

Agreed, but now you're getting into the area of "what should I tell students to give them the best chance?" rather than "what's more reliable?" Having students 'rely' on their reserves during a mal will help keep them alive, whereas having them 'rely' on their AAD will do the opposite. It's part of the art of how to tell someone something so they come away with the right assumptions - and often that means telling them something other than a bunch of statistics.

[Vallerina 2]

That, and relying on an AAD means relying on it and the reserve. So, you either put your trust in just the reserve, or you put your trust into both.

There's a thin line between Saturday night and Sunday morning

[mjosparky 3]

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That, and relying on an AAD means relying on it and the reserve. So, you either put your trust in just the reserve, or you put your trust into both.

Put your trust in yourself, know your gear and EP's. Always remember to think at 150 mph and avoid problems.

You are going to look "hot" in pink.

Sparky

My idea of a fair fight is clubbing baby seals

[op5e 0]

In short, no we can not teach the students that using reserve is always a safe option.

Should students cut away a (kinda deployed) main for an unknown (and possibility of failure) reserve.

I think that taking the risk in deploying the reserve for a student is more responsible than trusting the student to work out how to (for example) land with risers. I mean students are people who normally still jump with instructors and most would still not target assist themselves etc.. So to add another factor to landing may be enough to make a casualty. I know my friends 3rd jump he landed down wind, flared high and didn't plf. If there was a managable mal with his main and he was encouraged to stick with it I can asure you he would have had alot more damage than a broken arm.

Reliability of an AAD

I do not know about other DZs. Students at my DZ jump with an instructor, if they do not pull the instructor does. For a student the AAD only comes into action if a mal or the instructor doesnt hang on (which i have not heard of at my DZ). If a student sets off the AAD alot, they will get the "maybe skydiving is not for you" talk, or they may just not pass the AFF stages. If they are still on AFF they will still have an instructor so they other safety factor is still there. They may have proven to be fairly reliable, but there is still the human eliment that they were set and the odd chance it may not work so again you encourage best practices to the student (or newbie like myself).

My thoughts

With my limited knowledge, I would say that encouraging students to rely on the reserve is unforunately our only option. Because if we put any doubt in the reserve, people hesistate, and this means eating dirt. Skydiving is not without its risks, however we have to play the best hand we have. And students (including me) landing a perfect main is bad enough let alone adding the slider up, broken toggles, line break and so forth. Yes reserves do not have as good press as an AAD, however an AAD may also have a bad day, skydiving is not without risks and anyone participating should accept this.

[LawnDart21 0]

Thank you.

1000ft exit, I'm deploying my reserve. My main is small and unless I have intentionally packed it for a quick open, it likes (needs) 800 ft & terminal elocity to open. Reserves are designed to inflate quickly at high or in this case slow speed deployments.

Hope everyone had a good holiday weekend. I sure did.

--
My other ride is a RESERVE.

[kallend 1,623]

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That, and relying on an AAD means relying on it and the reserve. So, you either put your trust in just the reserve, or you put your trust into both.

No, the reserve won't deploy by itself. Either you, a RSL, or an AAD has to deploy it.

If your AAD gets involved it generally means that you already fucked up at least once on that jump.

...

The only sure way to survive a canopy collision is not to have one.

[Vallerina 2]

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Either you, a RSL, or an AAD has to deploy it.

I guess I'm just unsure of the question then. If you rely on the AAD, then you are also relying on the reserve unless your aad is on the main. Your aad may function correctly, but your reserve may have been packed with a lineover. Yeah, I know, even if you open your reserve, it may still have that lineover, so it's independent of opening method (although, it's more likely an aad fires while someone is headdown rather than them opening their reserve while headdown.)

There's a thin line between Saturday night and Sunday morning

[kallend 1,623]

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Either you, a RSL, or an AAD has to deploy it.

I guess I'm just unsure of the question then. If you rely on the AAD, then you are also relying on the reserve unless your aad is on the main. Your aad may function correctly, but your reserve may have been packed with a lineover. Yeah, I know, even if you open your reserve, it may still have that lineover, so it's independent of opening method (although, it's more likely an aad fires while someone is headdown rather than them opening their reserve while headdown.)

Well, we're all unsure of the question. How is reliability defined in a system that involves humans and equipment, and where one piece of equipment is optional and only involved when the human has already screwed up, and another (the reserve) has to work or you die.

If you look at in terms of failures, when a reserve is needed, failure of the reserve WILL kill you, failure of the AAD MAY kill you. So a reserve needs to be more reliable.

The question is ill-posed. But you're an actuary, so you can figure it out for us.

...

The only sure way to survive a canopy collision is not to have one.

[Vallerina 2]

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If you look at in terms of failures, when a reserve is needed, failure of the reserve WILL kill you,

Okay, I was looking at it in more of terms of "malfunction." A lineover may not kill you (but will probably seriously injure you.)

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So a reserve needs to be more reliable.

Well, yeah!

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But you're an actuary, so you can figure it out for us.

Not for long!

There's a thin line between Saturday night and Sunday morning

[Tf15 0]

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But you're an actuary, so you can figure it out for us.

Not for long!

And what are you going to be before long?

Three times is enemy action

[UDSkyJunkie 0]

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But there has been no incident that I know of where a modern AAD has not activated when needed.

I notice you're from Sweden, so I'm guessing you don't get the USPA parachutist magazine... if you did, I'd tell you to check this month's incident reports. Qutoed from the conclusions:

"it was confirmed that the AAD was on at the time he exited the airplane. Investigators on the accident scene also determined that the automatic activation device was still armed and activated properly in preparation for jumping. The AAD was sent to the manufacturer for testing. The manufacturer reported that the AAD funcitoned properly during testing."

Cause of death was listed as "failure to deploy either main or reserve parachute." The AAD in question was a modern design (Astra).

Now, this isn't to say that modern AAD's aren't EXTREMELY reliable, but this sounds (IMHO) to be a pretty clear case of AAD failure, though it surely would be nice to know why.

As for your actual question (and I won't claim to be an expert, this is just my $0.02), I think it's better to teach students, who are not particularly likely to be able to tell the difference between a malfunction that is landable and one that isn't or, for that matter, how to go about safely landing it to go strait for the reserve.

To give a real-life example: I knew a girl who was just off student status (25th jump), and got tension knots on one side of her canopy, inducing a slow turn and rendering one of the toggles useless. It was a big, docile 7-cell, and so it wasn't doing anything radical. She was able to steer it with the opposite toggle and decided to land it instead of cutting away. Everything was fine until about 20 feet when she went to flare... canopy went into a dive, and the result was a broken ankle. Now, nearly every experienced jumper who saw this or heard about it said they would have done the same thing (tried to land it), except for one difference: they would have taken the canopy strait in, not flared, and done a PLF. Most of those same people also said that at 25 jumps, it would probably have been a better idea to cut away. Why? Because 1) a lot of people at that level wouldn't know for sure wether it was landable and 2) a lot of people at that level would have made the same mistake, and tried to flare, simply because they don't know any other way to land.

I think if you ask around, you'll find a lot more people who have seen someone hurt trying to land something they thought was "quite landable" than getting rid of it and dumping the reserve... assuming, of course, that the reserve was within load limits and deployed at a reasonable altitude.

"Some people follow their dreams, others hunt them down and beat them mercilessly into submission."

[Cayce 0]

I'm too new to offer advice on how to teach students but I can offer the perspective of the student and tell how I interpreted the teachings when it counted.

I had a line over on AFF-2 with a spinning mal that I fought for maybe 1200 feet. I pulled whatever I could get my hands on but it still kept spinning. I watched my altitude get close to my hard deck and then I remembered the criteria for a cut away. “Can I control and land this chute?” As soon as I flashed to the answer I realized I had to cut. So I did and all worked out okay. From the student’s point of view, that single question was a moment of clarity. I didn’t know why the chute was smaller and pinched looking, I didn’t know why I was spinning, but I knew I couldn’t continue with the chute that I had so I went to EP.

From the student’s point of view I appreciated the easy equation of deciding to chop or not. As you get more advanced in jump numbers and see more things you may be able to quantify and evaluate a mal at a higher level, yet as a student I just had to ask one question to see if I was going to cut or not. Once asked, and obviously answered, I had no hesitation and I believe that it served me well with the outcome. Just my perspective…

[dragon2 0]

Well done
I think a small malfunction might be more dangerous than some wild spinner or something. People have died fixing a stuck brake line

I've had 2 little problems myself, one slider stuck up high (at the cascades I believe) that stayed there for 3000ft. Now this was a hopnpop form 9k, trying out a new canopy I was going to do crw with the next jump (hybrid triathlon 160). This canopy had no half brake setting yet which made the opening super soft which prolly cause the slider hang up. I remember thinking: Aww, I don't want to have my first cutaway for something woossy!
Ended up fixing the problem, but that took me 3k, leaving me at 5k with a big slow proparly-behaving canopy...

The next problem was also on one of these hybrid tri's, a 150 this time (wingload 1:1 for me). The brakeline was stuck, caught around itself but running free of the riser so I could flare a little bit. Winds were up, I thought, if I can't clear this by 4k I'm going to make my decision: chop it or land it. I think I would have chosen to stay with it, it being a large canopy for me. Although if the knot had come undone at flare time, OUCH!!
But again, I fixed it, this time by 5.5k so we still had some time to do the 2way stairsteps we had planned...

My first cutaway was a spinner, no hesitation there! After that, a lineover that pretty much behaved itself so since I was at 4k I thought I'd fool around with it a bit. Then it started to turn, and I got rid of it. But I remember thinking, Not again! and, Can I fix this?

In my mind, that is dangerous thinking.

A student might land an iffy canopy because he thinks he can fix it because he doesn't know better.

A more experienced jumper might do the same, because he fixed stuff before so knows it can be done.

I wonder how many up jumpers got hurt landing an iffy canopy when they just should've chopped it.... Or even tried fixing the canopy for too long so no more altitude to chop when they realised they couldn't, or even complete inattention at landing time, still trying to fix it! Although that's a different problem, stick to your harddeck...

ciel bleu,
Saskia

[RTB 0]

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Cause of death was listed as "failure to deploy either main or reserve parachute." The AAD in question was a modern design (Astra).

Thanks for the information.
The Astra is not really big in Sweden and it doesn't appear to be anywhere else either. I am not sure why FXC can't get it to be more popular. Maybe it just is not as reliable as a cypres? The Vigil is still quite new so we will have to see. It might be a stronger competitor though.

Even though my original thought with this thread was quite unclear, I think I got some good input which did help clarify the issue for me, so thanks everyone.

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