Another Vigil Anomaly

[Samurai136 0]

Yeah, see this thread in Safety and Training.

The short story is: Don't leave your Vigil equipted rig in the trunk of your car or out in direct sun on a hot day.

"Buttons aren't toys." - Trillian
Ken

[MakeItHappen 15]

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OK, can any of you enginer types explain to me WTF this means?

http://vigil.aero/pdf/statementactivations08-06.pdf

sounds like gobbltygoop doubletalk

My take on it is that the Vigil incorrectly equated Temp changes to altitude changes and fired the unit.

Pressure changes get equated to altitude changes and rate of change of altitude.
Temperature changes change pressure, but that does not necessarily mean that altitude has changed.

The algorithms, aka software, making the decisions to fire or not to fire are not correct.

The blurp does not actually say if these temp changes are because of external temp changes or components heating up.
It could be either or both. My guess is environmental changes because I do not think the power consumption, leading to Joule heating, is all that great in an AAD. The batteries would not last long if there was major component heating because of Joule heating.

An example of Joule heating is a hot laptop.

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Make It Happen
Parachute History
DiveMaker

[dorbie 0]

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>Can anyone do the math on how much tempature effects Pressure?

If you just heat a room, the pressure remains exactly the same (unless the room is airtight, which is very rare.) However, most AAD's use silicon pressure sensors, and silicon sensors are dependent partially on temperatures. Many have built-in temperature sensors that the processor can use to compensate for the temperature dependency, and others have compensation integrated into the device.

>Take 2 pressure readings at the ground, one at 75F and one at
>130F, what is the difference the Vigil sees?

An accurate mechanical altimeter, or properly compensated digital sensor, will not see a change.

An uncompensated sensor could see a 7% change in fullscale output during that temperature change. At sea level, that means a change of about 1.1 PSI, or about 2000 feet. (assuming a 15psig sensor.)

I just deleted a post about density altitude, which I think was in error since it's not the same as pressure variations with temperature and altitude AFAIK.

But it did leave me wondering what algorithmic compensation is in there for altitude variations with temperature (not exclusively sensor related) and if this was a factor. The issue here is not the correct compensation by temperature but that the device doesn't know that the temperature is in error w.r.t. atmospheric temperature.

The sudden introduction of a mode or compensation value after a marginal self test seems like a bad policy and the root cause regardless. Worst case the compensation should have been continuous and would have drifted back to nominal with cooling which is a better outcome than firing if/when some mode suddenly kicks in to produce a different value.

[kkeenan 13]

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I have the same strong reservation against Airtec, they 2 have little creditability regarding their statement (a.o. reported to have checked a AAD, which wasn't even sent to them)

That may be, but I am more willing to trust a manufacturer who makes a couple of administrative errors than one whose unit potentially fires me out the door of an airplane unannounced.

Kevin

_____________________________________
Dude, you are so awesome...
Can I be on your ash jump ?

[billvon 2,395]

>I am thinking that if a unit is turned on at 130F and then is cooled
>to 75F via an AC unit, the unit senses it is at 2000 feet underground.

If the Vigil's pressure sensor is not temperature compensated, then it will fire at a wide range of altitudes depending on how warm the rig is, how cold the air was during freefall and how the main/reserve was packed. I would find it hard to believe that any competent designer would not temperature compensate a silicon pressure sensor. More likely there's an odd software interaction between temperature compensation and speed sensing, but that's just a guess.

[flyer299 0]

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>I am thinking that if a unit is turned on at 130F and then is cooled
>to 75F via an AC unit, the unit senses it is at 2000 feet underground.

If the Vigil's pressure sensor is not temperature compensated, then it will fire at a wide range of altitudes depending on how warm the rig is, how cold the air was during freefall and how the main/reserve was packed. I would find it hard to believe that any competent designer would not temperature compensate a silicon pressure sensor. More likely there's an odd software interaction between temperature compensation and speed sensing, but that's just a guess.

It would be nice if Vigil would chim in. I know they want to protect their software by not giving up a lot of info, but in this case a little info could help us. If it is just a matter of don't use a vigil that has been heat soaked in a car trunk, then I can deal with that and I think the Vigil is a good unit. If it is beyond that, then I need to look at replacing my vigil with something else.

[USPA 0]

A possible misfire under investigation, stating they did a thorough research of the unit and concluded it was user error, while the unit wasn't even sent to them, is NOT a couple of administrative errors. This is simple 1 example. I don't want to bad mouth any manufactorer, but I am amazed how some people refer Airtec and think they are some kind of saints. All AAD manufactorers have made serieus mistakes and tried (succesfully or not) to cover them up. (Maybe Argus not yet, but they haven't been on the market very long, time will tell)

The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die...

[sundevil777 93]

The Joule is the metric (SI) unit of energy. It is not a type of heating. Anyway, electronics dissipate energy as heat.

We don't even know how long it takes for the temp to rise inside the unit, due to all the insulation. It might take hours for it to matter.

If I were going to keep using a Vigil, I'd also be turning it on/off for each jump to help keep the internal temp down as much as possible.

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

[billybobskydive 0]

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A possible misfire under investigation, stating they did a thorough research of the unit and concluded it was user error, while the unit wasn't even sent to them, is NOT a couple of administrative errors.

ok, now i am REALLY curious, give us all the details and all the dirt on this

[MakeItHappen 15]

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The Joule is the metric (SI) unit of energy. It is not a type of heating. Anyway, electronics dissipate energy as heat.

Joule is a metric unit for energy.

Joule heating is the name referred to electronics generating heat while a current is passed through a circuit.

Both terms are named after James Prescott Joule.

A google search can help those without a formal education in physics.

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Make It Happen
Parachute History
DiveMaker

[sundevil777 93]

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The Joule is the metric (SI) unit of energy. It is not a type of heating. Anyway, electronics dissipate energy as heat.

Joule is a metric unit for energy.

Joule heating is the name referred to electronics generating heat while a current is passed through a circuit.

Both terms are named after James Prescott Joule.

A google search can help those without a formal education in physics.

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I'm so sorry. I quickly assumed that it was just a made up term. I don't remember that term being used.

I do have a formal education in mechanical engineering, thermodynamics was my area of emphasis, but that was 20 years ago. So sorry to have offended without even bothering to look it up.

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

[Vectracide 0]

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Makes you wonder when the first person is going to die at the hands of this device. Or worse yet, a plane load of people when the PC gets sucked out the door and rips the tail off.....

------------------------------------------------------------ Another great reason to leave the door closed till atleast 1,000ft agl !!! All seatbelts off prior to opening the door.

Do you really think that this has anything to do with when the door is opened or not? What about the other 11.5k+ feet? Dont think it could happen then too?

This has nothing to do with a door SOP's people....it has everything to do with a device that has up to now, failed in many ways that Cypres's do not. There is no need to purchase this device when there is the Cypres 2 out there. Most peoples motivations for purchasing a Vigil, is quite simply cost. In this sport, saving a buck is everyone's motivation.......mine too. But when it comes to the "right" and "safe" gear.....I will not pinch pennies.

I will reconsider the purchase of a Vigil if the take them off the market....fix the problems, and do not re-release them until they meet up to, or exceed the current Cypress 2 standards.

I'm sure there are many out there that think that I am being dramatic about my stance in this matter......and it's not like what I believe matters anyways....I'm just a schmo jumper. I'm sure that some will say....well.....the issues with Vigils haven't put people in danger..... As far as I know, there was only one premature fire that involved a tandem, with no inflation of the reserve. That one incident was enough for me, just like Adrian Nichols incident was enough for me to turn off my cypress 1 when swooping.

What people have to realize is that besides the known...there are the unknown factors to consider, just like surprise we all got when Adrian died at the hands of a Cypress1 fire. Up until that point, we were all satified at the Cypress, as it worked great for many many years. Well, I cannot say the same for Vigils. They have obviously not taken the R&D from Airtec into consideration as much as they should have, and released a product way to early.

We all know of the issues that Vigils have up to date...some fixed, some not. What about the ones that we are not aware of yet?

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Controlled and Deliberate.....

[MakeItHappen 15]

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The Joule is the metric (SI) unit of energy. It is not a type of heating. Anyway, electronics dissipate energy as heat.

Joule is a metric unit for energy.

Joule heating is the name referred to electronics generating heat while a current is passed through a circuit.

Both terms are named after James Prescott Joule.

A google search can help those without a formal education in physics.

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I'm so sorry. I quickly assumed that it was just a made up term. I don't remember that term being used.

I do have a formal education in mechanical engineering, thermodynamics was my area of emphasis, but that was 20 years ago. So sorry to have offended without even bothering to look it up.

That's funny. I got my MS in Physics from Purdue in 1978.
I can't recall anytime during the intervening years doing something involving Joule heating in the interim.

Anyway, the potential for Joule heating being a root cause for this misfire is slim, wouldn't you agree?
IOW, it is more likely that the external environmental temps found a way to fool the Vigil algorithms.

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Make It Happen
Parachute History
DiveMaker

[bob.dino 0]

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A possible misfire under investigation, stating they did a thorough research of the unit and concluded it was user error, while the unit wasn't even sent to them...

Reference please? Where/when/etc?

[dragon2 0]

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A possible misfire under investigation, stating they did a thorough research of the unit and concluded it was user error, while the unit wasn't even sent to them...

Reference please? Where/when/etc?

Ask Henny (ParaShoot here) about that one.....

ciel bleu,
Saskia

[billvon 2,395]

>or components heating up.

If there's enough energy to heat components up, the battery won't last more than a few days. Assume you need half a watt to make a significant change in temperature. Even an excellent lithium battery only has about 21 watt-hours of energy, so your batteries would be dead after 2-3 days of operation.

[billvon 2,395]

A bit of further news on this:

Talked to Pat on Sunday, and he said that during the vigil misfire issue in the DC-9, the plane _pressurized_ - it did not depressurize. Pressurizing means that the airplane's cabin altitude went below ground level; depressurizing means it goes above ground level.

When I first heard about the Vigil misfire issue at Rantoul, I assumed that the aircraft experienced a transient depressurization, making the Vigil think it was momentarily rocketed to ~1000 feet, then dropped back down as quickly (within a few seconds.) And while there is no way for that to physically happen to a skydiver, I could see the Vigil firing if it did not have the Cypres logic to prevent such misfires.

However, in this case, the Vigil apparently thought it was dropped suddenly _below_ ground level and returned to the surface rapidly. Apparently it fires in that case as well. (This is an issue because this is what happens when you slam a trunk, or close the door on a well-sealed room.)

[flyer299 0]

Although I agree that is not a desired trait of an AAD, and Vigil should address this and fix it. My question is: Does this make it an unsafe unit to be jumping? So far I do not see anything (providing I give the unit the proper care), would cause an unsafe situation while skydiving.

Since this thread has started, I have payed close attention to the temps I expose my vigil (and my cypress 2 for that matter). If My rig ever gets left in the hot car, I make sure I let it sit for an hour or so in AC before I turn the unit on. Not sure if this helps, but it makes sense to me.

[sundevil777 93]

I don't think there is a means to reduce the pressure below what it is outside.

On the load I jumped (the first), the plane pressurized to -300 feet soon after closing up, including the time to taxi and take off. We stayed pressurized with the cabin altitude barely rising above 0 until about 8K, when we suddenly equalized, with a nice bit of fog for entertainment. I can't understand how they were not prepared to manage the internal pressure by manually controlling the outflow valves.

I'd still like to know how long you'd have to stay at -300 before the unit might recalibrate to what it thinks is a new ground altitude.

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

[ZigZagMarquis 8]

Bill... et all,

Wasn't there a thread floating around that tried to summarize all of the Vigil anomalies that have happened recently?

I'll admit, as a skydiver and rigger, I'm not "impressed" with the Vigil and would hesitate to put one on my Rig or recommend it to a friend... however... I'm trying to figure out if that's a correct impression or not and am thinking there's maybe a lot of duplicate info about Vigil anomalies (i.e. multiple threads/posts) about what's really the same thing that may be giving a false impression that there's more problems going on then what there is??

[billvon 2,395]

>Does this make it an unsafe unit to be jumping?

Under most conditions, and for most jumpers - probably not. If you're willing to put the extra care into it, and avoid situations where it may misfire (like extreme temperature swings, pressurizable planes, car trunks etc) then it might well be a way to save some money on an AAD.

[kkeenan 13]

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So far I do not see anything (providing I give the unit the proper care), would cause an unsafe situation while skydiving.

I guess as long as you don't mind the occasional repack and cutter purchase due to slamming your trunk lid. In my opinion, it seems that the Vigil's selling point of not requiring "maintenance" is overshadowed by it's need for "care".

Kevin

_____________________________________
Dude, you are so awesome...
Can I be on your ash jump ?

[alex_778 0]

But if I remember my consumer law correctly, its a long time since I did classroom law but, they have to pay any and all reasonable costs.

In the UK, and I would assume the US, it is reasonable for a customer to expect that an item is fit for the purpose it is intended and sold for. So, if an AAD malfunctions it is not fit for its intended purpose and any loss or repair should be met by the seller on behalf of the manufacturer. The seller then takes the faulty item and repair/replacement cost up with the manufacturer.

Therefore, if you have a misfire and need a new cutter you should get it free of charge along with the cost of the re-pack paid for too. Replacing the cutter should be no big deal as Vigil offer this anyway if the unit fires in a bona-fide save. So, if it fires in a bona-fide fubar it would be reasonable to expect a free replacement.

Where the word 'reasonable' is used I use it in the legal context of what would Mr Average expect.

[billvon 2,395]

> So, if it fires in a bona-fide fubar it would be reasonable to expect a free replacement.

Right. But most of Vigil's replies to misfires have been "it's supposed to do that."

[mjosparky 3]

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But if I remember my consumer law correctly, its a long time since I did classroom law but, they have to pay any and all reasonable costs.

Have you ever read the manual?


Disclaim

All the commercialised Vigils (100%) passed all our various tests, technical inspections as our quality control. However, we can’t totally exclude any malfunction on Vigil.
So, A.A.D. nv/sa declines any responsibility in regard to a slightest default occurred to a Vigil, which escaped detection during test.

In other words, you buy it you own it.

My idea of a fair fight is clubbing baby seals