Today's Message Index:
----------------------
1. 05:33 AM - Re: AeroElectric-List Digest: 19 Msgs - 09/18/07 (Ron Cox)
2. 07:16 AM - E/P mags (Michael T. Ice)
3. 07:27 AM - Re: EFIS as only reference??? (Valovich, Paul)
4. 07:56 AM - Re: Cessna Split Switch (Robert L. Nuckolls, III)
5. 07:58 AM - of line until Friday (Robert L. Nuckolls, III)
6. 08:12 AM - Re: EFIS as only reference??? (Mike)
7. 10:41 AM - Re: EFIS as only reference??? ()
8. 11:16 AM - Re: EFIS as only reference??? ()
9. 11:35 AM - Re: EFIS as only reference??? (Bruce Gray)
10. 12:43 PM - Re: EFIS as only reference??? (Mike)
11. 02:38 PM - Re: EFIS as only reference??? (Peter Pengilly)
12. 03:46 PM - Re: EFIS as only reference??? (Terry Watson)
Message 1
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Subject: | Re: AeroElectric-List Digest: 19 Msgs - 09/18/07 |
Ron,
I can name many airplanes that have EFIS only and are certified under
part 25. The newer Airbus A318, 319, 320, 321, 330, 340, 380 and the
Boeing 777 just to name a few. Take a close at the newest stuff, the
backup is now an EFIS display.
Mike Larkin
-------------------------
Mike,
Not one of those airplanes has ONLY a single EFIS and no backups.
I fly the 777 and it definitely has multiple backups. I think an OBAM
airplane with only electronic instruments could be engineered to be safe
enough to fly IFR,
But none of the systems out there aee reliable enough to make me feel safe
with NO backup of any kind.
And if I made a mistaken assumption that there was only one system, and
that's not correct, then part of my message (i.e. "no backup") would not
apply. But all of Bruce's points still do if the backups are all EFIS.
I'm sorry, but as good as Bob's architecture suggestions are (and I'm usin
them on my Glasair), they can't replace a failed device.
I'd still feel better on the 777 with some sort of non-EFIS backup, but I'm
satisfied that no reasonable person would argue that any GA EFIS (nor power
distribution system) even approaches the reliability of what I fly behind,
and I've seen 2 system failures on those in my time watching them.
Fortunately, I had something to revert to. That was my point.
Ron Cox
...... Original Message .......
On Tue, 18 Sep 2007 23:55:35 -0700 AeroElectric-List Digest Server
<aeroelectric-list@matronics.com> wrote:
>Ron,
>
>I can name many airplanes that have EFIS only and are certified under
>part 25. The newer Airbus A318, 319, 320, 321, 330, 340, 380 and the
>Boeing 777 just to name a few. Take a close at the newest stuff, the
>backup is now an EFIS display.
>
>Mike Larkin
>
>
(via Treo e-mail)
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Hello,
I have been reading the efis thread and saw the comments about the E/P mags.
Since this thread seems to have taken a different direction and you are now
referencing P/E mags I would like to make a comment.
The following comments are my opinions.
The wiring diagrams in Bob's Z figures don't agree with the way the P/E mag
folks say to wire their products.
I think it is likely that some of the problems experienced with P/E mags is
because they were wired wrong.
I suggest that if your going to use P/E mags wire them like Emagair says and
follow their directions.
Mike
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Subject: | Re: EFIS as only reference??? |
I'm at the wiring stage of my RV-8A project:
* Z-13/8 with either dual Lightspeeds or one Lightspeed/one P-mag
(anyone used the latter configuration?)
* AFS-3500,
* TruTrak ADI Pilot II
* Garmin 496
* Heated pitot
* Back up airspeed, altimeter and VSI
The underlying design philosophy: The EFIS is going to fail during this
flight; and if in the goo, what are you going to do?
1. EFIS fails; electrical system ok - use the ADI and 496.
2. Primary electrical system failure - Switch to essential bus;
know battery status
3. Total electrical system failure / or simultaneous EFIS / ADI
failure - Rely on EFIS battery and 496 battery to land asap.
4. Total electrical system failure and total EFIS failure (no
battery backup) - use battery-powered 496 instruments display; know
where the ground is and get VFR asap.
5. Total electrical failure, and both EFIS and 496 battery backups
fail - One of the reasons God invented life insurance - sometimes it
just ain't your day.
The point is - in our experimental world it's all about probabilities of
failure and risk management. Risk cannot be eliminated, only understood
and managed.
Just my biased opinions.
Paul Valovich
N192NM Reserved (again)
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Subject: | Re: Cessna Split Switch |
At 02:10 AM 9/19/2007 -0400, you wrote:
>Left side is Alt and Right side is Battery. The confusion is that on the
>left side(Alt) in the middle is a single terminal and at the Bottom(off
>position) is a double pronged terminal. On the right side(Battery) in the
>middle is a double pronged terminal and at the bottom(OFF) there is a
>single terminal marked with 'N'. The problem is that it looks nothing
>closely related to the Z-13 diagram for an alt/bat switch where there are
>two terminals on the battery side and 4 terminals on the alt side. Ohm
>testing does not answer the question as to what do the terminals
>respectfully get connected to. There are no other markings on the switch
>except 'made in mexico'. Thanks in advance Mike H 9A
The Cessna split rocker is a custom part by Carling made first
for Cessna and I think picked up by the rest of the world. If
you have not yet cut a hole, consider switching to a DPDT-ON-ON-ON
switch like that depicted in the Z-figures and offered by B&C
as their S700-2-10. This offers the same functionality as
the split rocker but mounts in a single round hole and looks
like the rest of the switches. It's probably less expensive
too.
Your "right" and "left" references on the rocker switch may
not be relevant if the switch can be turned over in the hole.
I.e., "up" can be either direction. The way to tell how to
hook it up is test which position of both rockers opens both
switches. This is the DOWN position of the switch. One of the
rockers can be independently placed in the ON position without
disturbing the other - this is the BATTERY switch. The other
rocker will be the alternator side.
Bob . . .
----------------------------------------
( "Problems are the price of progress. )
( Don't bring me anything but trouble. )
( Good news weakens me." )
( -Charles F. Kettering- )
----------------------------------------
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Subject: | of line until Friday |
Hopping on the big iron bird in a couple of hours to go support
a client. Will be back on line Friday.
Bob . . .
----------------------------------------
( "Problems are the price of progress. )
( Don't bring me anything but trouble. )
( Good news weakens me." )
( -Charles F. Kettering- )
----------------------------------------
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Subject: | EFIS as only reference??? |
Paul is one of the brightest people on this site. He is able to see the
forest through the trees.
Mike
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Valovich, Paul
Sent: Wednesday, September 19, 2007 7:26 AM
Subject: Re: AeroElectric-List: EFIS as only reference???
I=92m at the wiring stage of my RV-8A project:
* Z-13/8 with either dual Lightspeeds or one Lightspeed/one P-mag
(anyone used the latter configuration?)
* AFS-3500,
* TruTrak ADI Pilot II
* Garmin 496
* Heated pitot
* Back up airspeed, altimeter and VSI
The underlying design philosophy: The EFIS is going to fail during this
flight; and if in the goo, what are you going to do?
1. EFIS fails; electrical system ok ' use the ADI and 496.
2. Primary electrical system failure ' Switch to essential bus;
know battery status
3. Total electrical system failure / or simultaneous EFIS / ADI
failure ' Rely on EFIS battery and 496 battery to land asap.
4. Total electrical system failure and total EFIS failure (no
battery backup) ' use battery-powered 496 instruments display; know
where the ground is and get VFR asap.
5. Total electrical failure, and both EFIS and 496 battery backups
fail ' One of the reasons God invented life insurance - sometimes it
just ain=92t your day.
The point is ' in our experimental world it=92s all about
probabilities of
failure and risk management. Risk cannot be eliminated, only understood
and managed.
Just my biased opinions.
Paul Valovich
N192NM Reserved (again)
"http://www.matronics.com/Navigator?AeroElectric-List"http://www.matroni
cs.com/Navigator?AeroElectric-List
"http://forums.matronics.com"http://forums.matronics.com
7/29/2007 11:14 PM
7/29/2007 11:14 PM
Message 7
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Subject: | EFIS as only reference??? |
Options,
I will be using the new Aspen Avionics PFD (now) and MFD when
released. The advanced MFD provides the backup instruments when #1 dies.
Both have built in battery backup which is charged by the system when
things are working normally (assume most days).
My engine is a Subaru which is equally dependent on juice and
arguably more important than a few gauges if I can actually see out the
window. My MFD will be slaved to the backup system per Z19. Per crash
landing instruction, nose goes towards the ground and you land as tail
low as possible to save your neck. I have never yet stalled an aircraft
with the nose pointing down - not to say it has not been done. Bottom
line - if I am satisfied that z-19 is providing reasonable redundant
protection to my engine, I need to have the same security with my efis.
To help my lights and engine out situation Aspen has included a
backup GPS inside their PFD and backup MFD. So, lights out, engine out -
headed for the trees tail low at least I can push the nearest button to
see where I could have gone.
One thing only Paul has mentioned is probability. Remember that from
statistics class? Yup, that's what the insurance companies use to figure
out your life expectancy, when you will crash etc. I have no sample data
from the nay-sayers of e-Panel only flight indicating more than 50 hours
a year and specific exposure to the even the slightest risk (night, wx,
snow, almost ice, etc). I do most of my flying at night because I like
it - less traffic, tower has time to talk to me, no sun in my eyes etc.
Is it risky? Absolutely, but I am always fascinated on my return by the
absolute barren stillness at my airport (200 planes are sleeping). Where
is all the risk? sleeping in the hangar? You can't eliminate risk, only
mitigate it. If your exposure is incredibly low and you have done
everything in your power to control your environment - you have nothing
to mitigate against.
To the earlier statement about cost, big iron and whatever the Aspen
system is certified for most aircraft and will certainly be found in
much bigger carbon fibre than mine. On top of that it cost about the
same as a good set (mid-continent or similar) of six pack gauges. Their
system is certified without the use of backup steam gauges. Does that
mean it's perfect? 'course not, but nothing else is either. We make our
decisions and move forward with them.
P.S. As far as an independent backup gauge is concerned, I have an
independent AOA meter which if used properly can be used to control
speed and angle when crash landing in clear weather. Where I live (PHL)
you probably won't like your landing choices anyway, but at least your
glide angle will be really nice.
By the way it was a wonderful but sad week at Reno. If you didn't hear
families lost three pilots to various forces. The first incident
occurred Tuesday right after take-off in absolutely perfect weather.
Engine stopped, plane stalled, pilot killed. The plane stopped 30 yards
from the runway. That's probability. At this point I am not overly
perplexed about the security of what Aspen has spent 20 million dollars
developing. In a year or two we'll all be using those crazy new
lithium-nano batteries to run the entire airplane.
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Valovich, Paul
Sent: Wednesday, September 19, 2007 10:26 AM
To: aeroelectric-list@matronics.com
Subject: Re: AeroElectric-List: EFIS as only reference???
I'm at the wiring stage of my RV-8A project:
* Z-13/8 with either dual Lightspeeds or one
Lightspeed/one P-mag (anyone used the latter configuration?)
* AFS-3500,
* TruTrak ADI Pilot II
* Garmin 496
* Heated pitot
* Back up airspeed, altimeter and VSI
The underlying design philosophy: The EFIS is going to fail
during this flight; and if in the goo, what are you going to do?
1. EFIS fails; electrical system ok - use the ADI and 496.
2. Primary electrical system failure - Switch to essential
bus; know battery status
3. Total electrical system failure / or simultaneous EFIS /
ADI failure - Rely on EFIS battery and 496 battery to land asap.
4. Total electrical system failure and total EFIS failure
(no battery backup) - use battery-powered 496 instruments display; know
where the ground is and get VFR asap.
5. Total electrical failure, and both EFIS and 496 battery
backups fail - One of the reasons God invented life insurance -
sometimes it just ain't your day.
The point is - in our experimental world it's all about
probabilities of failure and risk management. Risk cannot be eliminated,
only understood and managed.
Just my biased opinions.
Paul Valovich
N192NM Reserved (again)
Message 8
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Subject: | Re: EFIS as only reference??? |
Bruce:
What lighting protection does your little EFIS system installation have?
May be the box it self has DO specs, but the installation does not.
One lightning strke *could* take it ALL OUT. George
>From: "Bruce Gray" <Bruce@glasair.org>
>Subject: RE: AeroElectric-List: EFIS as only reference???
>
>I don't think that is correct. The heavy iron EFIS systems are designed
>to the same standards as our little airplane systems. Those are DO 160
>(electrical protection) and DO 178 (Software coding and testing). There
>aresome under 100k systems that meet those standards.
>
>Bruce
---------------------------------
Moody friends. Drama queens. Your life? Nope! - their life, your story.
Message 9
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Subject: | EFIS as only reference??? |
My airplane is plastic and I stay away from lightning as far as
possible.
Another reason to have a vacuum ADI.
Bruce
<http://www.Glasair.org> www.Glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
gmcjetpilot@yahoo.com
Sent: Wednesday, September 19, 2007 2:16 PM
Subject: Re: AeroElectric-List: EFIS as only reference???
Bruce:
What lighting protection does your little EFIS system installation have?
May be the box it self has DO specs, but the installation does not.
One lightning strke *could* take it ALL OUT. George
>From: "Bruce Gray" <
<http://us.f431.mail.yahoo.com/ym/Compose?To=Bruce@glasair.org&YY=129
95&y5be
ta=yes&y5beta=yes&order=down&sort=date&pos=0>
Bruce@glasair.org>
>Subject: RE: AeroElectric-List: EFIS as only reference???
>
>I don't think that is correct. The heavy iron EFIS systems are designed
>to the same standards as our little airplane systems. Those are DO 160
>(electrical protection) and DO 178 (Software coding and testing). There
>aresome under 100k systems that meet those standards.
>
>Bruce
Message 10
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Subject: | EFIS as only reference??? |
I=92ve been struck by lighting 3 time in my flying career. If you are
in
a little airplane and get struck, the least of your worries will be
worrying if the EFIS continues to work. And that goes double for the
E-glass guys.
Mike
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
gmcjetpilot@yahoo.com
Sent: Wednesday, September 19, 2007 11:16 AM
Subject: Re: AeroElectric-List: EFIS as only reference???
Bruce:
What lighting protection does your little EFIS system installation have?
May be the box it self has DO specs, but the installation does not.
One lightning strke *could* take it ALL OUT. George
>From: "Bruce Gray" <HYPERLINK
"http://us.f431.mail.yahoo.com/ym/Compose?To=Bruce@glasair.org&YY=129
95&
y5beta=yes&y5beta=yes&order=down&sort=date&pos=0"Bruce@glasair.
org>
>Subject: RE: AeroElectric-List: EFIS as only reference???
>
>I don't think that is correct. The heavy iron EFIS systems are designed
>to the same standards as our little airplane systems. Those are DO 160
>(electrical protection) and DO 178 (Software coding and testing). There
>aresome under 100k systems that meet those standards.
>
>Bruce
"http://www.matronics.com/Navigator?AeroElectric-List"http://www.matroni
cs.com/Navigator?AeroElectric-List
"http://forums.matronics.com"http://forums.matronics.com
7/29/2007 11:14 PM
7/29/2007 11:14 PM
Message 11
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Subject: | EFIS as only reference??? |
I know because most of it runs on a Windows based operating system, and
has not been designed from the start to comply with the relevant
standards (if it had Windows would not have been used). There is no way
that Windows anything will ever be compatible with a real time safety
critical system (because it wasn't designed from the outset for that
task). That's not to say it wont work just about all of the time, but do
you want to risk your life on it?
But that's not the point. The point is that you are taking a risk by
using 2 non certified systems to back each other up. Its difficult to
quantify that risk without in depth knowledge of how each system was
designed & built, and that information is difficult to come by. The fact
that Cheltons are so expensive illustrates the issue, very few people on
this list could afford one - come to that I suspect not many could
afford a Garmin G900!
I know that Trutrak makes very good equipment, there are also many other
companies that make rather poor stuff and its difficult to tell by
looking at the outside. Its not about meeting govt standards, industry
standards are just as strict. If it were easy to make a robust system
cheaply I suspect Garmin would be offering one, that their cheapest is
around $50K (I think) might be a hint as to the scale of the problem.
Peter
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Mike
Sent: 18 September 2007 18:01
Subject: RE: AeroElectric-List: EFIS as only reference???
Peter,
How do you know! I'm sure all that part 25 stuff has nice stamps on the
paperwork but it is still put together by people. How do you know the
stuff that we buy won't make the standard? Having to meet FAA standards
cost money, don't you believe that a product could meet a standard
without the government? For example, the autopilots out there certified
for use in small planes are in my 28 years of experience less or equal
to the Truetrak product. Also the Chelton system is certified to part
25 standards by TSO and is under $100,000.
Mike
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Peter
Pengilly
Sent: Monday, September 17, 2007 11:38 PM
Subject: RE: AeroElectric-List: EFIS as only reference???
<peter@sportingaero.com>
Mike,
You're missing the point. The hardware & software of EFIS in part 25
aircraft, and their back-ups, are designed, built and tested to
standards
far in excess of anything that we can afford to put in our airplanes.
They
are not comparable.
Regards, Peter
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Mike
Sent: 17 September 2007 23:41
Subject: RE: AeroElectric-List: EFIS as only reference???
Ron,
I can name many airplanes that have EFIS only and are certified under
part 25. The newer Airbus A318, 319, 320, 321, 330, 340, 380 and the
Boeing 777 just to name a few. Take a close at the newest stuff, the
backup is now an EFIS display.
Mike Larkin
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ron
Cox
Sent: Monday, September 17, 2007 10:48 AM
Subject: AeroElectric-List: EFIS as only reference???
> Time: 01:24:52 PM PST US
> Subject: RE: AeroElectric-List: switch suitability?
> From: "Chris Johnston" <CJohnston@popsound.com>
>
...
> your reply that i have too many and the
> wrong things is curious to me. the aircraft has no "conventional"
> instruments, so the EFIS and AHRS are essential.
Chris,
This statement indicates to me that you may harbor a certain naivete
about
the current state of development and reliability of EFIS/AHRS systems.
As a
new pilot with an instrument rating, it's natural to want to have the
greatest thing that comes along. I just bought a really cool EFIS
add-on
system for my Glasair project and I use it in my Cessna now, but it's
not
the only way to fly the airplane. I like it alot, but I don't count on
it
to keep my body parts within their casing. IT will be the backup in
case of
failure of my primary (traditional) instruments.
But if you are working on a plane you intend to fly in real IFR, and do
indeed have NO backup instruments, I'm afraid your electrical
distribution
system is far from the weakest point in your airplane. If you plan to
fly
only VFR, then the systems are even less "essential", and again, they
don't
need to be on the "E-bus".
There are currently NO EFIS systems out there for the market most of us
are
looking at (i.e. non-military, non-$100K) that have the kind of proven
reliability and lack of single-point failure possibilities that even the
old
vacuum gyro systems should be configured to give you.
In other words, if you do have, say an internal power supply failure, or
complete display failure in your EFIS system, what is your plan? Your
E-bus
may be powered, and if you follow Bob's advice, it almost surely will
be,
but how are you going to control the airplane????
Bob's advice to look again at your system is good advice (as it
usuallyall
is.) He always reminds us to look at the possible failure points in a
design, and decide which are not problems, which are, and to figure out
how
to assure that those which are problems are prevented to the greatest
extent
possible.
I strongly suggest you do some additional research before trusting your
life
to what's really generation 1.5 of general aviation EFIS systems.
They're
great, when they work, and they usually do, but it's nothing short of
criminally negligent to put ALL your eggs in that kind of basket. There
isn't anywhere near enough industry-wide experience with these systems
yet
to even KNOW what their real in-service failure rate is, let alone
determine
whether it's low enough or not.
Do a little Googling on EFIS systems, no matter which brand, and you'll
find
a legion of folks who love them, but don't trust them, and they'll tell
you
perfectly good reasons why. EVERY system I've looked into has its share
of
"boy am I glad I had a backup" stories.
What GA airplane do you see out there that has only an EFIS and no
backups?
There's a reason for that.
Ron Cox
(Old pilot with an instrument rating, and one who has well over 10,000
hours
flying behind fantastically expensive commercial EFIS systems, but we
have
backups!)
7/29/2007 11:14 PM
7/29/2007 11:14 PM
7/29/2007 11:14 PM
7/29/2007 11:14 PM
Message 12
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Subject: | EFIS as only reference??? |
In general, "Certification" means that at some point the system passed
certain set of criteria and the design was frozen at that point. It won't
get any better unless something is found to be broken and has to be fixed,
otherwise it is a design frozen in time, like a Lycomming 0-360 or a Cessna
172. Sure, they change -but only in ways that won't make them go through
certification again.
I don't know about most of the great looking new low cost EFIS systems, but
I know for certain that my Bluemountain EFIS/one does not use a Windows
operating system, and I wouldn't veto a system that did. I have read that
Windows is very stable when it is used in a system that is isolated from
other software. An EFIS is not constantly being exposed to various other
programs, viruses and hackers like a PC is. It is isolated, or used with
limited and tested outside software.
The downside of most "certified" products is that they are the best that a
company could come up with and get through the tests and to market, at some
point in the past. If you feel the need for a certified engine, get one, but
I don't think your certified Lycoming is any more reliable than my
non-certified Superior. If you don't trust non-certified avionics, then pay
the price for the tried and tested and blessed, but don't expect to get if
for anything like the price of the non-certified, and don't expect to have
the advantages of the latest technology.
It would seem that many of those who fly big airplanes for a living tend not
to trust little airplanes anyway, especially the ones with only one engine
and certainly not the ones that don't have dual redundant certified IFR
avionics.
And if it wasn't built by "certified" A&P's in a "certified" shop, forget
about it!
Terry
RV-8A, Superior, True-Trak, Trio, Bluemountain, Airflow Performance -- all
uncertified
And none of it flying yet
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Peter
Pengilly
Sent: Wednesday, September 19, 2007 2:37 PM
Subject: RE: AeroElectric-List: EFIS as only reference???
<peter@sportingaero.com>
I know because most of it runs on a Windows based operating system, and
has not been designed from the start to comply with the relevant
standards (if it had Windows would not have been used). There is no way
that Windows anything will ever be compatible with a real time safety
critical system (because it wasn't designed from the outset for that
task). That's not to say it wont work just about all of the time, but do
you want to risk your life on it?
But that's not the point. The point is that you are taking a risk by
using 2 non certified systems to back each other up. Its difficult to
quantify that risk without in depth knowledge of how each system was
designed & built, and that information is difficult to come by. The fact
that Cheltons are so expensive illustrates the issue, very few people on
this list could afford one - come to that I suspect not many could
afford a Garmin G900!
I know that Trutrak makes very good equipment, there are also many other
companies that make rather poor stuff and its difficult to tell by
looking at the outside. Its not about meeting govt standards, industry
standards are just as strict. If it were easy to make a robust system
cheaply I suspect Garmin would be offering one, that their cheapest is
around $50K (I think) might be a hint as to the scale of the problem.
Peter
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