Official Statement Regarding Colorado Vigil Firings

[slotperfect 7]

Attached.

Posted by manufacturer's request.

Arrive Safely

John

[Ron 7]

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Conclusion: In those 2 cases the Vigils activated because the firing parameters were met.

And, IMO, it is a bad design if it can fire due to only the door opening.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[Jenn83 0]

Thanks for posting!

If anyone has any additional questions or concerns please feel free to PM me and I will do my best to address them.

--
Jenny

[beowulf 1]

It seems as though there is more to this then just the door opening. It seems as though there is more then just the door opening that caused the firing parameters to be met. Otherwise I would think there would be more of these incidents.

[theonlyski 3]

Have the vigils that experienced the firings been analized to see if there was some sort of defect in the electronics?

I know that sometimes electronics can burn out, have cold solder joints, or just plain stop working. I doubt that it was a manufacturing error because it sounds like a Vigil and a Vigil 2 have both experienced the issue, and they must have been made atleast a while apart from each other.

Im strongly considering buying a Vigil 2 (preferably a 3 if they come out sometime soon) but I would like to know what the issue with these was.

"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
I'm an asshole, and I approve this message

[peregrinerose 0]

Would the fact that the firings occurred in CO and the testing occurred in FL, at totally different altitudes MSL have any effect on the result?

Do or do not, there is no try -Yoda

[brettski74 0]

On the positive side, I'm glad that Vigil have posted this statement and it does address some of the issues raised. It's also re-assuring to know that they are working to figure out the conditions that caused the issue and hopefully address it.

I understand the point about activation altitude and flight level restrictions - interesting point. I don't really have a problem with the activation altitude, nor do I think that it's really a solution to anything to increase it. I also think that this could be an advantage - albeit a minor one over other designs.

On the down side, I see a lot of technical detail mentioned in a way to suggest that the Vigil design is superior, but I'm not sure that it is. You talk about detecting freefall in 5/8 of a second and therein lies the problem. Yes - Vigil has has had saves, but can you identify any of those where deciding that it was in freefall in 5/8 of second would have made any difference over whether it took 3 seconds to make that decision? From stable flight (0 m/s vertical speed) and with the unit in Pro mode, it would take about 3.5 seconds to reach activation velocity under gravitational acceleration and assuming no drag. In practice, it will take longer than this due to drag. With this in mind, I find it difficult to see why it's so important to decide that we're suddenly in freefall and act in 5/8 of a second. Based on my understanding of them, I do believe that Vigil's firing parameters are too simple. For a typical low-pull/no-pull scenario, the skydiver will have been in freefall for much longer than 3 seconds, so again, I don't see why it's advantageous to decide that we're suddenly in freefall and activate so quickly.

Finally, from what I understand of the Vigil firing parameters, I still believe that they are too simple. As far as I understand, it's really only considering the altitude and the rate of change of altitude (vertical speed). I think that at the very least, it should also be considering second differences (ie. rate of change of vertical speed) to rule out situations which could not be possible under gravitational acceleration and if such a situation is detected, it is probably safer to do nothing than to just wildly activate because it thinks we're suddenly in freefall. Freefall just doesn't happen that suddenly.

[tdog 0]

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For a typical low-pull/no-pull scenario, the skydiver will have been in freefall for much longer than 3 seconds, so again, I don't see why it's advantageous to decide that we're suddenly in freefall and activate so quickly.

What about the non-typical situation where a cutaway occurs stupid low and the AAD needs to get the reserve out ASAP? 3 seconds = death.

[skypuppy 1]

advantageous to decide that we're suddenly in freefall and activate so quickly.

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What about the non-typical situation where a cutaway occurs stupid low and the AAD needs to get the reserve out ASAP? 3 seconds = death.
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then you need a sky-hook, or at very least an rsl....

ps if you're gonna be stupid, you gotta be tough....

If some old guy can do it then obviously it can't be very extreme. Otherwise he'd already be dead.
Bruce McConkey 'I thought we were gonna die, and I couldn't think of anyone

[sundevil777 94]

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For a typical low-pull/no-pull scenario, the skydiver will have been in freefall for much longer than 3 seconds, so again, I don't see why it's advantageous to decide that we're suddenly in freefall and activate so quickly.

What about the non-typical situation where a cutaway occurs stupid low and the AAD needs to get the reserve out ASAP? 3 seconds = death.

It still will be able to measure the increase of speed up until it reaches the vertical speed activation criteria. I don't think that a cypres must be above that speed for 3 seconds before firing.

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

[Jenn83 0]

The Vigils that experienced the firings were sent to AAD in Belgium for testing. I know that after their initial analysis of the units nothing immediately appeared to be out of order with the units but as I said, that was the initial analysis. I haven't yet received any further results from the testing process on those units.

We'll definitely try to post as much information about any and all results but if you'd like to PM with your e-mail address I can be sure that you receive updates that way as well.

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Would the fact that the firings occurred in CO and the testing occurred in FL, at totally different altitudes MSL have any effect on the result?
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The results referred to in AAD's statement are just from the initial test. We're actually looking into doing more tests at the same altitude (preferably from the same DZ) and hopefully even with the same aircraft.

[brettski74 0]

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What about the non-typical situation where a cutaway occurs stupid low and the AAD needs to get the reserve out ASAP? 3 seconds = death.

It's no different. Vigil doesn't know that you've cut away. Vigil only knows about atmospheric pressure readings from which it deduces altitude and from there, the vertical component of your velocity. It's not limited to only making the decision to fire based on the data from when you cut away. It has the benefit of all the data from the time you left the plane - much more than 3 seconds.

The purpose of the device is to save a skydiver in freefall in a low-pull/no-pull situation. It does so by deploying your reserve canopy. If the device deduces vertical acceleration that exceeds gravitational acceleration by a significant margin, then the pressure variations that it's seeing are clearly not due to freefall which means this is a situation that the device and/or reserve canopy was not designed to handle. Firing in such a situation is not a good idea as you have no idea what the situation is or what the outcome of attempting reserve deployment might be. Better to leave that decision to the skydiver who has significantly more information about what's going on.

We generally all leave from aircraft in relatively level flight, where the vertical component of our velocity is zero or very close to it. Freefall speeds capable of meeting the firing parameters simply do not happen when exiting from level flight in the short timeframes that Vigil's press releases imply are important. If you want to make the decision to fire based on 5/8 of second worth of data, that's fine, but it's not as important as the statement appears to make it to be.

Don't get me wrong. I'm not simply trying to bash Vigil. I have a Vigil 2 in my own rig. I'd like to see a better product.

[tdog 0]

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It has the benefit of all the data from the time you left the plane - much more than 3 seconds.

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We generally

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meeting the firing parameters simply do not happen when exiting from level flight in the short timeframes that Vigil's press releases imply are important.

Lots of assumptions that every skydive follows certain parameters.

AADs have to handle non-expected skydives too:

***Wingsuits where decent rates can be slow prior to canopy deployment

***aircraft collisions (skydiver hits tail),

***canopy collisions (normal skydive goes to crap at 500 feet),

***sudden changes due to readings in burbles (a freeflier backflying transitioning to bellyflying will have a sudden pressure change due to where the AAD is mounted on the body) - etc -

add all a lot of confusion to the matter of writing code to make this work.

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Don't get me wrong. I'm not simply trying to bash Vigil. I have a Vigil 2 in my own rig. I'd like to see a better product.

Me too...

I see two major flaws with the vigil:

FLAW 1(my opinion)
Vigils tend to fire, or have in the past tended to fire, due to sudden pressure changes. Hangar doors, car trunks, aircraft doors and sudden pressurization changes in pressurized aircraft

SOLUTION
Learn what the maximum change in velocity a skydiver can achieve in any freefall scenario, including pressure changes due to tumbling out of control. Any sudden pressure changes beyond this expected pressure change causes a one second pause before firing, but after one second, if firing parameters are still met, fire... (Actual times would be determined by looking at all the previous incidents to learn what fooled the Vigil in sudden changes)

FLAW 2(My Opinion)
The Vigil will stay on indefinitely when it is around 150-200 feet off of the calibration altitude. In other words, when a skydiver takes a vigil home and home is not the same altitude as the DZ, the vigil stays on. The skydiver then travels to a DZ at a different altitude than home for vacation and experiences a vigil fire in freefall. This happened with two brothers I know who share rigs who both thought the other brother turned on their AAD weeks after their last jump at home. Vigil believes this is a benefit as skydivers (or military jumpers) who jump into the night don't want their unit to shut off while in the aircraft or in freefall. However, the industry is accustomed to the Cypres mentality of, "don't turn it off, it will do it on it's own".

SOLUTION
The vigil has a wonderful text capable screen. The software could display "Not on ground" when the vigil thinks it is in an aircraft. AND, when the vigil has been on for more than a logical day of skydiving, it could say, "Powered on for 765 hours. DO NOT JUMP. See manual." Thus training the skydiver and warning them something is wrong.

[brettski74 0]

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Lots of assumptions that every skydive follows certain parameters.

Not lots of assumptions. Just one assumption that the device is being used to skydive on Earth, in which case we have a very good idea of what is possible under gravitational acceleration from Earth's gravity. I think that's a fairly safe assumption.

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***Wingsuits where decent rates can be slow prior to canopy deployment

***aircraft collisions (skydiver hits tail),

***canopy collisions (normal skydive goes to crap at 500 feet),

All of these involve a skydiver falling under gravitational acceleration due to Earth's gravity, so my previous statements still apply. The only scenarios to which my previous statements do not apply are those where the skydiver is being accelerated toward the ground by something other than gravity, such as perhaps rockets, a plane in a nosedive or perhaps even something like a microburst, but I cannot think of any such scenarios where a reserve canopy deployment makes a lot of sense without more information that is not available to the AAD firmware.

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Learn what the maximum change in velocity a skydiver can achieve in any freefall scenario, including pressure changes due to tumbling out of control.

This is pretty much exactly what I'm saying, although I think you're talking about the maximum rate of change in barometric pressure. We know what the maximum rate of change of velocity of pretty much anything in freefall thanks to a guy called Sir Isaac Newton. Pressure measurement issues due to body position and burbles could very well mean that we need to allow for larger short term variances in the measured pressure. The longer term trend should still be consistent altitude changes under gravitational acceleration.

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Any sudden pressure changes beyond this expected pressure change causes a one second pause before firing, but after one second, if firing parameters are still met, fire...

What is the purpose of this pause? You've determined that something extraordinary is going on, but despite the designers having no understanding of what this scenario is nor designing the device to handle it, you're just going to wait a second and then go ahead and fire anyway? AADs are designed to solve a fairly specific issue. They are not designed to solve all kinds of weird and wonderful situations. If the device identifies that something is going on that it's programming was not designed to deal with, it should keep quiet and let the human make the decisions.

[kallend 1,647]

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What about the non-typical situation where a cutaway occurs stupid low and the AAD needs to get the reserve out ASAP? 3 seconds = death.

It's no different. Vigil doesn't know that you've cut away. Vigil only knows about atmospheric pressure readings from which it deduces altitude and from there, the vertical component of your velocity. It's not limited to only making the decision to fire based on the data from when you cut away. It has the benefit of all the data from the time you left the plane - much more than 3 seconds.

The purpose of the device is to save a skydiver in freefall in a low-pull/no-pull situation. It does so by deploying your reserve canopy. If the device deduces vertical acceleration that exceeds gravitational acceleration by a significant margin, then the pressure variations that it's seeing are clearly not due to freefall which means this is a situation that the device and/or reserve canopy was not designed to handle. .

A Kalman filter that includes the relevant laws of physics would take care of that.

...

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

[tdog 0]

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***Wingsuits where decent rates can be slow prior to canopy deployment

***aircraft collisions (skydiver hits tail),

***canopy collisions (normal skydive goes to crap at 500 feet),

All of these involve a skydiver falling under gravitational acceleration due to Earth's gravity, so my previous statements still apply.

In another post you said the AAD has benefit from all the data from the time the skydiver left the plane, more than 3 seconds. I disagreed with that, and posted scenarios here where the AAD does not have that data. A good wingsuiter has the acceleration profile of an aircraft, not one of a freefalling human... Until pull time when he reaches back and has his mal and suddenly goes in freefall. A canopy collision at 500 feet, without an RSL, where the main is destroyed to the point of freefall speeds gained, occurs minutes after the freefall is over and again resembles the profile of an aircraft, not a freefalling human... So there is no benefit of "all the data from the time the skydiver left the aircraft."

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What is the purpose of this pause? You've determined that something extraordinary is going on, but despite the designers having no understanding of what this scenario is nor designing the device to handle it, you're just going to wait a second and then go ahead and fire anyway?

Yep... I suggested a pause be written into the software and implemented ONLY when the AAD determined that it had instantaneous data that appeared to meet firing parameters, but only when that data exceeded the expected acceleration due to gravitational forces, thus something that is highly unlikely to be a skydiver in freefall.

The purpose - to average out the spikes from aircraft doors, car trunks, and hangar doors suddenly opening, but still keep the AAD working if the spike was due to something that happened in freefall. You could combine this with your comment of the historical data "from the time the skydiver left the aircraft" and change when and how long the pause is implimented if the unit has determined it is in freefall already.

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If the device identifies that something is going on that it's programming was not designed to deal with, it should keep quiet and let the human make the decisions.

The problem with that... We all know a skydiver's altimeter can read dramatically off when they are doing a rodeo and riding a wingsuiter's back, because they are in the burble... AADs live in the burble of a belly flier, AADs live in the pressure zone of a back flier, and AADs get thrown in and out of pressure when a skydiver is tumbling in or out of control.

I am willing to bet that a car door slamming can be about the same pressure change as a belly flier suddenly flipping to their back. Either way, this is impossible acceleration under Earth's gravity because of how the acceleration was measured...

I suggested the brief pause to be implemented when the AAD experiences a spike, but moments later, if the firing parameters are STILL met, fire... If the spike was just a spike, then stand down...

But again, I don't think it is wise to just shut off, like you suggested, and let the human make decisions, if the pressure readings are outside of typical acceleration characteristics.... Unfortunately, the misfires documented are probably close enough to typical skydiving pressure changes such as rolling from your back to your belly and changing the pressure zone of the AAD that any code you are suggesting that simply ignores impossible acceleration, would not prevent the misfires, because the misfires are probably occuring too close to the actual skydiving profile and not close enough to the impossible acceleration profile.

[sundevil777 94]

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In another post you said the AAD has benefit from all the data from the time the skydiver left the plane, more than 3 seconds. I disagreed with that, and posted scenarios here where the AAD does not have that data.

Why would the AAD not have the data? My understanding was that a cypres has a sampling rate that is slow until it realizes that you are on your way up in the airplane, then it will sample at the same, high rate until you return to the ground. If that is incorrect, please let me know. If that description is true, then it doesn't matter whether you're doing a wingsuit jump, a hop and pop, cut away after being under an open canopy for a long time, start falling fast due to a canopy collision, or are staying with the plane on the way down - the AAD has all the data. How it uses that data is the important part.

I think Airtek has a very good idea of what the burble effects are, have taken this into account, and the fact that jumpers have been saved while falling unconscious and tumbling should make this a non-issue.

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

[piisfish 135]

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FLAW 2(My Opinion)
The Vigil will stay on indefinitely when it is around 150-200 feet off of the calibration altitude. In other words, when a skydiver takes a vigil home and home is not the same altitude as the DZ, the vigil stays on. The skydiver then travels to a DZ at a different altitude than home for vacation and experiences a vigil fire in freefall. This happened with two brothers I know who share rigs who both thought the other brother turned on their AAD weeks after their last jump at home. Vigil believes this is a benefit as skydivers (or military jumpers) who jump into the night don't want their unit to shut off while in the aircraft or in freefall. However, the industry is accustomed to the Cypres mentality of, "don't turn it off, it will do it on it's own".

SOLUTION

Solution B is : the screen should show : RTFM

The so called "problem" is known, and people still use a Vigil the same as they would use a Cypres. The users are WRONG (even if I also dislike that "flaw")

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

[tdog 0]

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SOLUTION

Solution B is : the screen should show : RTFM

The so called "problem" is known, and people still use a Vigil the same as they would use a Cypres. The users are WRONG (even if I also dislike that "flaw")

hahaha

(this is, for other readers, discussing the fact the Vigil will stay on forever if it is not at altitude of the DZ for which it was turned on. If your home is higher than the DZ, it will stay on forever unless you turn it off. The manual recommends turning it off always prior to leaving the DZ. If you don't, when you travel to another DZ, if you don't cycle the power at the new DZ, it will be calibrated to the wrong DZ... This caused a vigil fire at 5,000 feet thanks to the home DZ being 5,100 MSL and the visiting DZ being sea level and the user thinking a friend turned on the AAD on a borrowed rig.)

The users were wrong, but then again, incidents happen because no one is perfect. Are you perfect? I am not! I know because I have looked over at my Vigil on my sofa and seen it on days after I left the DZ thinking, "oops..." I also know exactly how my Vigil owning friend had a Vigil fire in freefall with 9 other people next to him... And while it occurred because they were brothers, borrowing rigs, and each assumed the other got the gear ready that morning and that was why they thought the AAD being on was normal - I know a lot of couples who jump and I have seen one person get all the gear ready while the other manifests and organizes the jump... It could happen to them too. I also jump at a DZ where 10-20% of the customers are students at a military college where they, due to budgets, borrow rigs all the time in a barter system. They are at risk of not knowing if the AAD being on is "normal".

Sure, they SHOULD ask, "did you turn this on?" - or they SHOULD make a policy of "never turn on the other person's AAD" or "Always cycle the power if you are not 100% sure"....

But Vigil has the technology built in already to write words on their display... After all, mine says "bat ok, cut ok, ENJOY, PRO".... If the software already has a timer built in (and it does, because it will turn off if on the DZ's ground) - then a few lines of code should be able to add redundancy to the system and simply eliminate this human error issue!

I think the Vigil displaying/cycling on the screen "On Ground, Pro, 10Hr" would be the most elegant AAD out there... It would tell the user that the unit is calibrated to the ground, what model it is, and how long it has been on... It would be far superior to the Cypres if it did!

[brettski74 0]

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In another post you said the AAD has benefit from all the data from the time the skydiver left the plane, more than 3 seconds. I disagreed with that, and posted scenarios here where the AAD does not have that data. A good wingsuiter has the acceleration profile of an aircraft, not one of a freefalling human... Until pull time when he reaches back and has his mal and suddenly goes in freefall. A canopy collision at 500 feet, without an RSL, where the main is destroyed to the point of freefall speeds gained, occurs minutes after the freefall is over and again resembles the profile of an aircraft, not a freefalling human... So there is no benefit of "all the data from the time the skydiver left the aircraft."

In all of these situations, the jumper exited the aircraft, so why is the device not capable of logging measurements from that point?

If you have a canopy collision at 500 feet, it's a fairly safe bet that at some point prior to that, you exited an aircraft. There is no reason why the device cannot be logging data during this descent, so I don't understand how we don't have the benefit of more than 3 seconds of data. That aside, it's also extremely unlikely that an AAD would save you in such a situation. Under my canopy, I descend at about 8 metres per second. With no drag, it would take about 2.7 seconds under gravitational acceleration to reach the speed needed to fire. In that time, I would have fallen about 200 feet. In the real world, there will be considerable drag, so the acceleration will be reduced which in turn increases both the time and distance you will fall before reaching firing speeds.

If you strike the tail on exit, I'm guessing that you're at full altitude, so why is there a need to deploy the parachute in less than 3 seconds from the exit? The firing parameters won't be met until the skydiver is at a lower altitude, so it's going to take somewhere in the vicinity of 50 seconds or more for that to happen. Even if this is some kind of accidental exit while climbing through 1000' or less, it's still going to take more than 3 seconds for the falling skydiver to reach the activation speed of the AAD.

Wingsuiting... There will still be a long trend of descent data for something like 2 minutes or more before the wingsuiter reaches an altitude that meets the firing parameters. At what altitude does the wingsuiter throw their pilot chute? If we're talking about a "normal" deployment altitude with a malfunction happening, then we're above 2000' to start with and it will take well over 5 seconds to descend from deployment altitude to the 840' activation altitude. If this is a low pull, how low is your descent rate? 40mph? That's a little under 18 metres per second. With drag, it's going to take more than 2 seconds to accelerate to the activation speed of 35 metres per second. This is also assuming that the descent rate has been so slow that Vigil didn't think you were in freefall yet. The Vigil manual doesn't seem to have any details about what conditions need to be met for it to decide you're in freefall. 2 seconds is still much more than the 5/8 of a second that Vigil takes to decide that it's in freefall and should activate. They make a big deal about this in their literature as though it's a good thing, but I can't think of a single scenario where it's necessary to makes such a fast decision.

[tdog 0]

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In all of these situations, the jumper exited the aircraft, so why is the device not capable of logging measurements from that point?

Because... This thread started with a post about an activation in an aircraft. The AAD "knew" it was above the ground... When the pressure changed, it thought a skydiver was in freefall and needed to fire.

Yes, you could write code that would prevent misfires on the ground by simply staying "disarmed" on the ground or within X feet of the ground.... But it would not have prevented the incident posted here, because the AAD "experienced an aircraft ride."

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2 seconds is still much more than the 5/8 of a second that Vigil takes to decide that it's in freefall and should activate. They make a big deal about this in their literature as though it's a good thing, but I can't think of a single scenario where it's necessary to makes such a fast decision.

Why not ask them? I think the 5/8th of a second is important when you are already going terminal velocity and burning towards the ground in a no-pull/no-out situation, and that is where they seem to market that speed... I think we tend to agree that, if the skydiver is going 0-20 MPH towards the ground, 5/8 of a second is too quick to make "fire decisions" as it would be impossible to accelerate to 75+mph in 5/8th of a second, and thus the code should "average out" any spikes due to sudden pressure changes.

[sundevil777 94]

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In all of these situations, the jumper exited the aircraft, so why is the device not capable of logging measurements from that point?

Because... This thread started with a post about an activation in an aircraft. The AAD "knew" it was above the ground... When the pressure changed, it thought a skydiver was in freefall and needed to fire.

I do not understand your answer, please restate what you're trying to say.

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Yes, you could write code that would prevent misfires on the ground by simply staying "disarmed" on the ground or within X feet of the ground.... But it would not have prevented the incident posted here, because the AAD "experienced an aircraft ride."

Other AADs have the ability to prevent such misfires. Please explain again why the design of the vigil should not be expected to do the same. I don't understand your point.

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

[billvon 2,427]

>2 seconds is still much more than the 5/8 of a second that Vigil takes to decide . . .

This talk of "decision time" is not an accurate representation of what's going on. When the Cypres's firing parameters are met, it fires within milliseconds. When the Vigil's firing parameters are met, it fires within milliseconds. There is no delay when either unit is thinking (in effect) "I know I have to fire now, but I'm going to wait a while to close the cutter switch."

[tdog 0]

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>2 seconds is still much more than the 5/8 of a second that Vigil takes to decide . . .

This talk of "decision time" is not an accurate representation of what's going on. When the Cypres's firing parameters are met, it fires within milliseconds. When the Vigil's firing parameters are met, it fires within milliseconds. There is no delay when either unit is thinking (in effect) "I know I have to fire now, but I'm going to wait a while to close the cutter switch."

You replied to my post as if I wrote the 5/8 second thing, but it was a quote of Brett in my post...

So, to make this accurate, I will copy what Vigil says in their release as I don't want to add confusion:

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...In a low cutaway situation, the
system must detect the freefall as soon as possible and activate as fast as possible to release the reserve.

That’s why the Vigil only needs 5/8 sec to register it is in freefall and if the
next measurement point is still in freefall it will activate in 125 msec and the
loop will be cut within ± 2 msec.
The way our system is designed has proved this concept and has saved many
lives in such critical situations (16 out of the 73 life saves).

I think Brett is disputing the concept In a low cutaway situation, the system must detect the freefall as soon as possible and activate as fast as possible to release the reserve. If I am reading his argument correctly, he is saying that the unit should take into consideration the current speed of the skydiver towards earth, and the maximum possible acceleration that skydiver could achieve due to gravity, and IF the skydiver somehow accelerated with ludicrous speed towards earth, not fire because impossible acceleration has been achieved, and thus the speed readings are inaccurate... I think he is disputing that a skydiver can accelerator from under canopy to firing parameter speed in less than 5/8 of a second.

I wonder however, after having video of a spinning mal where I looked at my altimeter twice, thus know my decent rate to be well over 50 MPH - when does the Vigil (at what speed) leave "freefall mode" and return to "resting mode", where it would need to re-detect freefall as they say it needs to...

[tdog 0]

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Other AADs have the ability to prevent such misfires. Please explain again why the design of the vigil should not be expected to do the same.

I honestly don't know if you are right or wrong in the ability to prevent. It appears that Cypres "got lucky" in a few cases where their parameters kept the unit from firing, not by some complex code, but by having parameters that were out of bounds for the situation at hand... Example, if I remember correctly, the World Record Vigil fires in the pressurized aircraft occurred because the Vigil does not have the same "no fire zone" like the Cypres does near the ground... The pressurized aircraft were in the "no fire zone" of the Cypres, but not the Vigil. Luck (or better parameter choosing), not code, saved the day on that one.

And on the most recent incident, Vigil explains how the same thing could have happened to Cypres customers:

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Another point is that if the plane reaches 1500ft, the Cypres also becomes
active and if the plane descends to the activation zone, the Cypres will also
activate if the pressure variation measured is fast enough. Certainly in
Student mode (Cypres= 13 m/s, Vigil = 20 m/s). So the same potential
problems can be experienced with all AAD’s depending on their parameters.