Which would you trust more?

[Nick 0]

Here's a thought I got from the “How many of you DON'T wear altimeters?” thread and a number of discussions I've had recently.


What would you trust most, a visible altimeter (e.g. Alti2) or an audible altimeter (e.g. Protrack).

The number of visible altimeters I've seen being dropped out of helmets, with needles that wobble around or start somewhere around 1500 or where the actual item rattles. As opposed to an electronic device that normally remains protected in your helmet, has self checking capabilities etc. (remember this is going to be pretty similar to the Cypres except it doesn’t go back to the factory every 4 years).

Having worked in electronics design and manufacture (including reliability testing) for approx. 10 years I’d like people’s points of view. Also if anybody has any info on what kind of reliability testing was conducted on the Cypres and Protrack I‘d be interested to see a summary.

Cheers

Nick
Gravity- It's not just a good idea, it's the LAW!

[wzettler 0]

I went with audible (because I have 2) but I would have preferred the choice of eyes....

I think when Jesus said "love your enemy" he probably meant don't kill them.

[billvon 3,063]

Visible. What noise does an audible altimeter make when it fails? Compare that to a visible altimeter. If you look at it and it says 8000 feet, and you look at it 10 seconds later and it still says 8000 feet - you know you have a broken altimeter. This concept is used for aircraft instruments, as well. An aircraft instrument does not have to be 100% reliable, but it DOES have to indicate when it has failed (i.e. no signal, no power etc.)

[vt1977 0]

Yeah likewise, where’s the option of “my eyes”?!

Vicki

[rehmwa 2]

I always carry both. But I tend to rely on the audible more and more lately.

Frankly, the number one thing I do is glance past my teammates to the horizon occasionally and see where the horizon line is compared to someone on level with me. That can be used as a pretty good estimate of altitude when near breakoff time.

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[Nick 0]

I did consider that but what I was after was an answer to whether peopled trusted mechanical devices or electronics (remembering that mechanical devices can still go wrong and are much more lightly to give a spurious reading).

Nick
Gravity- It's not just a good idea, it's the LAW!

[WILDBILLAQR 0]

I use one of each. I also check the horizon.

----------------------------------------------
"Thats not smoke, thats BUCKEYE!!"
AQR#3,CWR#49

[AggieDave 6]

You also left out a digital visual alti to your question. Same with the mechanical, you can look and see its broken. At that point you know to really pay attention to whats going on, where you are, how low you look and how low/high everyone else is (which can help you determine breakoffs, etc as long as they don't go low).

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[selbbub78 0]

my audible is a 2ndary alt. I'll go with my wrist or chest mounted one. I'd probably even go with my "eyes" before my audible. Just in case my wrist messes up.

"Women fake orgasms - men fake whole relationships" – Sharon Stone
"The world is my dropzone" (wise crewdog quote)
"The light dims, until full darkness pierces into the world."-KDM

[CanuckInUSA 0]

During the final few days of the Eloy Holiday Boogie, the chin cup on my helmet cam broke and I made 4-5 jumps without my audible. And wouldn't you believe it, it was a refreshing experience where I had to go back to my early days in this sport where I wasn't relying on an audible. Now don't get me wrong, now that my helmet has been fixed, I have gone back to using my audible, it's just that it was a good experience for me to jump without it as it made me much more aware of my surroundings and I had to rely on my eyes and my senses to stay altitude aware.

Try not to worry about the things you have no control over

[Blahr 0]

So far I have never once heard the audible until after I'm open

I think I will rely on the visual one

[Ron 10]

#1. Eyes

#2. Visual..since you can tell its broken.

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

[RyanofOZ 0]

Eyes for me. If I use audible, it is a secondary device.

Oz

[jaybo 0]

Blahr, what audible are you using and where is it mounted? With the 2 volume settings on my inside the helmet (open face Hawkeye) mount Pro-track, I have not heard the lower volume setting alarm at terminal.

[jdthomas 0]

I use both, I hate to give up an idea so easy but why don't we have a vibrate model like the one in my phone?
Man I like those calls when I carry the phone in my pocket..
The thing buzzes at your altitude and you get a good cheap feel and then you dump your load so to speak!

www.greenboxphotography.com

[darkwing 5]

I use two audibles and one visible on every jump. I agree with Billvon's logic. Failure is more obvious on a visible alti.

-- Jeff
My Skydiving History

[councilman24 37]

In addition, any electronic altimeter, audible or visual, by definition WILL fail when the batteries die. It might let you know, it might not.

My 1980 Altimaster II has never skipped a beat.

BTW I do wear an audible. I'm not a complete dinosaur. But I have no problem giving either the visual or audible to someone who for got theirs.

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

[freeflyguy 0]

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#1. Eyes

#2. Visual..since you can tell its broken.

That is my first vote too. Eyes, awareness.

----------------------------
bzzzz

[FrogNog 1]

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I always carry both. But I tend to rely on the audible more and more lately.

Frankly, the number one thing I do is glance past my teammates to the horizon occasionally and see where the horizon line is compared to someone on level with me. That can be used as a pretty good estimate of altitude when near breakoff time.

Uh, isn't the horizon always at the same location - 90 degrees from straight down? Or are you saying you look at the horizon and see what you can see, or what features have moved above the horizon (like mountaintops)?

-=-=-=-=-
Pull.

[Airborne03 0]

haha neither...isnt that what a cypress is for

"Airborne all the way"
EL Cantador Rodriguez

[gremlin 0]

I dont really trust either as they read differently. Have started breaking off formations at 4000ft when my audible has gone off only to glance at my visual and see it read 4300. Think I need to get the visual tested in a pressure chamber. Too much throwing it at people who have cocked up my formation...it couldn't have been me...definitely not...

I'm drunk, you're drunk, lets go back to mine....

[PhillyKev 0]

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During the final few days of the Eloy Holiday Boogie, the chin cup on my helmet cam broke and I made 4-5 jumps without my audible. And wouldn't you believe it, it was a refreshing experience where I had to go back to my early days in this sport where I wasn't relying on an audible. Now don't get me wrong, now that my helmet has been fixed, I have gone back to using my audible, it's just that it was a good experience for me to jump without it as it made me much more aware of my surroundings and I had to rely on my eyes and my senses to stay altitude aware.

I occasionally jump without my audible for the sole reason of makiing sure I haven't started becoming reliant on it.

I haven't jumped without my Alti2, but I have caught myself going to pull without having checked it (based on my view of the ground), then checking it to make sure I'm not too high. So, pretty sure I'm not relying solely on that, either.

I don't think I've ever been lower than my planned pull time without having checked it. Though I have gone lower due to other people in the air.

[crwmike 0]

I just count to three and pull

[Nullified 0]

***That is my first vote too. Eyes, awareness.

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First of all, I'm not attacking Ron, or Tandem Masters or Moderators or anyone else, so if you feel the need to become personally defensive, chew on a stalk of celery instead. OK.

I wonder how many people who claim that their eyes are their primary means of altitude awareness are being honest. Sure I trust my eyes more than my altimeter and I generally pay attention to what the Earth below me looks like, but I'll be honest, my eyes and my internal clock are my backups. And no, that sentence isn't in contradiction with itself.

I glance at my alti to tell me how high I am. As more time passes through freefall, I'll check my alti again and begin glancing at the ground to confirm that my alti is being honest and that I'm still at a safe altitude.

Speaking for myself, my eyes won't tell me whether I'm at 6000' as opposed to 8200', but I know that as long as I use them, they won't lie to me and tell me that I'm still safe when I'm really at 1800'.

Maybe this is what most people mean when they talk about their Alti's being secondary, and in that case I'm arguing semantics and interpretation.

The way I'm looking at it though, I'll use my eyes, which I trust more, to confirm or 'backup' what my alti is telling me, not with regard to actual altitude, but with regard to 'safe' Vs. 'unsafe' altitude.

Thanks for listening and not throwing half eaten food at me.

Stay safe,
Mike

Oh, I don't bother much with freefall anyway, so don't think that I think I'm a 500 jump wonder freefall skygod. Just making an observation is all. Actually, if anyone's got a half eaten pizza, you could throw that my way.

If you're gonna' be stupid, well, then you're most likely stupid.

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[Squeak 17]

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I always carry both. But I tend to rely on the audible more and more lately.

Frankly, the number one thing I do is glance past my teammates to the horizon occasionally and see where the horizon line is compared to someone on level with me. That can be used as a pretty good estimate of altitude when near breakoff time.

Uh, isn't the horizon always at the same location - 90 degrees from straight down? Or are you saying you look at the horizon and see what you can see, or what features have moved above the horizon (like mountaintops)?

No when you do rel work if you look to the horizon and see if it is at an angle below another flyer, check again in a few secinds and the angle will be smaller, if the horizon ever goes avoe the other flyer you are in a canyon

You are not now, nor will you ever be, good enough to not die in this sport (Sparky)
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