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Ack! My ACK!



 
 
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  #1  
Old July 9th 03, 05:10 AM
MikeremlaP
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Default Ack! My ACK!

Am wondering if there's a design flaw in the ACK E-01 ELT or just an anomaly?
Our unit went off by itself today because the battery in the remote panel mount
indicator died, triggering the ELT, and I'd like to know if anyone else has had
this happen?

If a dying battery in the remote ***always*** sets off the ELT, then this is a
design flaw. Everyone's ACK will eventually false alarm if the remote battery
isn't replaced on time. (And you know how we are with smoke detectors...)
Hmmm... maybe this explains all the false alarms CAP complains about?
-----------------------------------------------
I got a call from the airport today. They said the ELT from our plane in the
hangar was transmitting as of this morning.

That's strange. We last flew a few days ago. No ELT then. (The landings
haven't been THAT hard.) What could've happened?

In disbelief, I drove to the hangar, expecting this to be a false report. (Not
even sure how they could receive a signal, since the hangar makes a pretty good
shield. Turns out the CAP hangar is nearby, and they picked it up as they
taxied by.)

I unlocked the plane, and checked the panel indicator for the ELT. No flashing
LED showing activation. I punched the "Reset" button anyway. And then I
punched the "On" button. Hmmm... no flashing LED.

So I pulled out the handheld, and tuned 121.5. Sure enough, there was an ELT
signal, loud and clear. I hit the hard switch on our ACK, and that stopped it.

I pulled the remote, and sure enough, the 6v Lithium battery is down to 2v.

I'd like to know if anyone else had this same problem, where a dying battery in
the panel remote triggers the ELT? It could simply be an anomaly. But if a
sizeable number of you have had this happen, then it's a design flaw.

But you might not know it happened if someone doesn't alert you that your ELT
has triggered. If the CAP wasn't nearby, I suspect our ELT would have drained
itself down to zero, and I would have blissfully flown around for the next year
(time to annual) thinking the ELT was functional. (It's not like there's a
"Checklist" item, to test the ELT before every flight. But in light of this I
think I'll make a monthly item on my Palm Pilot.)

So if you have an ACK ELT, you may wish to check it from the panel mounted
remote to make sure everything is working.

FYI, I installed the Lithium battery in August 1999, and expected it to last
until 2004. (I don't know if there's any current drain on it when the ELT is
in standby.) But it quit almost 4 years to the month, in 2003. My new
replacement cycle will be every 3 years now.

Hope this helps,

Mike Palmer
Excellence in Ergonomics
  #3  
Old July 9th 03, 07:30 PM
BD5ER
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***always*** sets off the ELT, then this is a
-design flaw.

And what credentials do you possess to make this determination?

Jim


Same as yours and mine - he's the end user, the one that paid for the thing.
  #4  
Old July 9th 03, 07:57 PM
Jim Weir
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Ah, no. He is entitled to say that he thinks that the failure of the battery is
the proximate cause of the ELT going off. He is not entitled to say that this
is a design flaw unless he could have done the original design himself...just
like you cannot say that the BD-5 has an inherent aerodynamic design flaw
because a few of them have turned into smoking holes. UNLESS you are capable of
doing the design analysis yourself, in which case I will respect your judgement.
In ANY case, you would be irresponsible to make such a statement until you had
contacted the original designer and discussed the matter with him/her.

Jim


cal (BD5ER)
shared these priceless pearls of wisdom:

-***always*** sets off the ELT, then this is a
--design flaw.
-
-And what credentials do you possess to make this determination?
-
-Jim
-
-Same as yours and mine - he's the end user, the one that paid for the thing.

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com
  #5  
Old July 9th 03, 11:29 PM
Corrie
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All due respect to your credentials, Jim, I think you're wrong on both
counts.

1. In my experience, a call to the manufacturer of a product about a
potential problem with that product generally results in a CYA
response: There's nothing wrong with our wonderful product, there
must be something wrong with the way you are using it.

Asking whether others had shared his experience was not insulting the
company. It's quite possible that someone else might reply, "I had
the same experience, and it turned out I had accidently shorted the
frammel connector to the glidget nut - check your connections" in
which case Mike would feel chagrined at his slight importuning of the
fine engineers at ACK (which I'm sure they'll recover from without
flame-mail or slander litigation). it's also possible that several
folks folks might pipe up and say, "Hey, I though it was just me that
happened to!" in which case a critical design flaw (and an ELT failing
with no notice is a critical flaw, would you not agree?) is brought to
light in such a way that it can't be swept under the rug (not that ANY
manufacturer of repute would ever do that.)

2. One does not have to be capable of creating a design in order to
point out a flaw in a design, especially a usability flaw. Perhaps
the system is working exactly as designed - and it's a bad design.
Designers and engineers are human, and we make poor decisions just
like pilots do. (I know, you're shocked - shocked! that such a thing
could be.) It's perfectly permissible for users to point those things
out. In fact, sometimes users are the only ones who CAN point these
things out, because they put the product to the test in the ral world.


At the very least, I'd bet a dollar to a doughnut that a bunch of
folks are going to check their ELTs this week instead of taking them
for granted. And that just might save a life. Isn't that what this
group is supposed to be about?


Corrie Bergeron - designer and user

Jim Weir wrote in message . ..
(MikeremlaP)
shared these priceless pearls of wisdom:

-Am wondering if there's a design flaw in the ACK E-01 ELT or just an anomaly?

What did ACK say? You **DID** call them and ask before insulting them publicly
on this newsgroup, yes?

-
-If a dying battery in the remote ***always*** sets off the ELT, then this is a
-design flaw.

And what credentials do you possess to make this determination?

Jim



Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

  #6  
Old July 10th 03, 04:14 AM
Gerry Caron
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"A@AA" wrote in message
...
Jim, assuming that the ELT does act as he believes it does - that it

alarms when
a secondary battery dies, and that happens shy of it's stated service

life - I'd
think that was bad.


That's one helluvan assumption. Is 3 years in use shy of it's stated
service life? What is the stated service life? Did it alarm because the
battery died or was there a short in the remote that drained the battery and
triggered the ELT? If there was a short, was it internal to the battery
(random failure), caused by a cold solder joint (workmanship),
water/moisture intrusion or excessive vibration from a poorly located mount
(bad installation), or a large current induced into the connecting cable
(secondary effect)?

There are lots of possible failure modes and results. Until you've analyzed
the failure and determined the root cause, you can draw no conclusions
regarding the design or anything else.

As for being bad, maybe not. What does the System Safety Analysis say?
Which is worse; a latent failure where it doesn't work when you need it or a
false alarm? At least with the false alarm you are alerted to the fact it's
not working. You do monitor guard, don't you?

If you can't call it a design flaw, what do you call it? A Bad Thing(tm)?


Maybe, or possibly a Feature? ;-) It could be that way because it's the
safest failure mode. Or maybe the company (and their lawyers) wanted it
that way. Much more likely to be sued if it fails to work after a crash
than if it false alarms. Then again, it could be a very unlikely random
failure mode.

And don't try to argue that random failures are design flaws. Take a course
in reliability engineering. If you're bored, read MIL-HDBK-17.

I agree, he should contact the manufacturer before coming to an open forum

and
posting stuff like this, it may be a completely different situation than

what
he's describing.


He absolutely should. The holder of a TSOA is legally bound to investigate
reported failures of their product. (note the key word "reported.") If
they find a design flaw that compromises flight safety, they must report it
to the FAA within 24 hours. They'll probably argue with the FAA over the
corrective action, but they will report it. If they don't report it, they
risk having their TSOA pulled and their business shut down. Even minor
issues can result in SILs or SDRs, which exist to improve the product and
safety so it pays to report it.

But it might be *exactly* as he's describing, and I don't
think his lack of an EE degree means he can't reasonably comment that a
product's designed in failure mode is awfuly unwise.


True, it might be exactly as described, but I'm with Jim on this one. I
don't think that even with an EE degree he can reasonably comment on the
design. Only someone who has specific knowledge of the design and can
evaluate all the data surrounding the failure can make a reasonable comment.

In 26 years in aerospace, I've learned a few things. One of the big ones is
to not publicly speculate on a failure--you're probably wrong and will only
make a fool of yourself. Get the data, analyze it, verify cause and effect,
and only then make your statement.

Gerry


  #7  
Old July 10th 03, 11:22 AM
Robert Bonomi
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Default

In article ,
Gerry Caron wrote:

"A@AA" wrote in message
...
Jim, assuming that the ELT does act as he believes it does - that it

alarms when
a secondary battery dies, and that happens shy of it's stated service

life - I'd
think that was bad.


That's one helluvan assumption. Is 3 years in use shy of it's stated
service life? What is the stated service life?


I hate (not! to inject facts into a good argument, but the original
poster _did_ indicate the stated service life. FIVE YEARS. It died
at just short of _four_. *HIS* revised new* 'replacement schedule', based
on the observed evidence, is now three years.

Did it alarm because the
battery died or was there a short in the remote that drained the battery and
triggered the ELT? If there was a short, was it internal to the battery
(random failure), caused by a cold solder joint (workmanship),
water/moisture intrusion or excessive vibration from a poorly located mount
(bad installation), or a large current induced into the connecting cable
(secondary effect)?

There are lots of possible failure modes and results. Until you've analyzed
the failure and determined the root cause, you can draw no conclusions
regarding the design or anything else.
As for being bad, maybe not. What does the System Safety Analysis say?
Which is worse; a latent failure where it doesn't work when you need it or a
false alarm? At least with the false alarm you are alerted to the fact it's
not working. You do monitor guard, don't you?

If you can't call it a design flaw, what do you call it? A Bad Thing(tm)?


Maybe, or possibly a Feature? ;-) It could be that way because it's the
safest failure mode. Or maybe the company (and their lawyers) wanted it
that way. Much more likely to be sued if it fails to work after a crash
than if it false alarms. Then again, it could be a very unlikely random
failure mode.


That last can be dismissed. The original poster stated "*IF* a dying
battery *ALWAYS* causes a false alarm..." as the qualifying condition for
claiming design flaw. That precludes the possibility of an 'unlikely
random failure mode'.

And don't try to argue that random failures are design flaws. Take a course
in reliability engineering. If you're bored, read MIL-HDBK-17.

I agree, he should contact the manufacturer before coming to an open forum

and
posting stuff like this, it may be a completely different situation than

what
he's describing.


He absolutely should. The holder of a TSOA is legally bound to investigate
reported failures of their product. (note the key word "reported.") If
they find a design flaw that compromises flight safety, they must report it
to the FAA within 24 hours. They'll probably argue with the FAA over the
corrective action, but they will report it. If they don't report it, they
risk having their TSOA pulled and their business shut down. Even minor
issues can result in SILs or SDRs, which exist to improve the product and
safety so it pays to report it.

But it might be *exactly* as he's describing, and I don't
think his lack of an EE degree means he can't reasonably comment that a
product's designed in failure mode is awfuly unwise.


True, it might be exactly as described, but I'm with Jim on this one. I
don't think that even with an EE degree he can reasonably comment on the
design. Only someone who has specific knowledge of the design and can
evaluate all the data surrounding the failure can make a reasonable comment.

In 26 years in aerospace, I've learned a few things. One of the big ones is
to not publicly speculate on a failure--you're probably wrong and will only
make a fool of yourself. Get the data, analyze it, verify cause and effect,
and only then make your statement.

Gerry




  #8  
Old July 10th 03, 03:41 PM
Ron Natalie
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"Richard Riley" wrote in message ...

Every li battery device I have says the battery's good for 10 years.

That doesn't mean that the unit rates the battery that way. My ELT
rates the remote battery at something like 5 years.


  #10  
Old July 11th 03, 02:16 AM
Del Rawlins
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Default

On 10 Jul 2003 04:32 PM, Gerry Caron posted the following:

Aviation is a small community. Avionics is only a small part of that.
Everybody knows everybody or someone who does. This isn't an industry
where companies can afford to alienate customers.


JPI still seems to be in business.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/
 




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