Cost of Cockpit Instruments

In article .com,
Le Chaud Lapin wrote:

Continuing with this example, let's suppose I take my $700 instead and
buy a standard basic PC from Dell. The Inspiron 531S is selling for
$529US:
http://configure.us.dell.com/dellsto...en&oc=DDCWGC2&
s=dhs.
Note that it comes with 17inch, LCD color monitor, $160GB hard drive,
"in-flight movie viewing system" (DVD drive and Windows Media
Player). I would want two of these machines in my airplane, so let's
say cost is $1058.

problem: the hard drive won't survive high altitude flying. Do you want
your computer to die just because you fly at 13000'?

--
Bob Noel
(goodness, please trim replies!!!)

Le Chaud Lapin wrote:
So a different approach might be to stop making finished systems and
instead focus on components. Manufacturers would make controls in
sensors in wide variety, all conforming to USB standard. A (cheap)
commodity PC would be able to control everything. And (licensed)
software developers could do their part.

Since when are software people licensed? Who does the licensing?
What are the exams? What is the followup to maintain it?

I just came back from a business trip and found my WinXP box dead.
As with every trip, I had shut everything down, disconnected the
power from the wall (actually, the UPS but that's another story).
Got home, reconnected everything, hit the power switch. Nothing.
Dead. I've already spent a couple hours diagnosing with no luck.

I can see your scenario of a cheap, COTS PC running the systems in my
cherokee crashing on my at night in IMC. Sure. Right. And my lawyers
will be in touch with your lawyers.

Do I like paying $675 for a new AI? Nope. Or $3400 for a new NAV/COM?
Or $6000 + installation for a 430? Nope. But in spite of what we think
of the FAA bureaucracy, the engineering and related groups really are
quality-driven. When I get a TC/STC/TSO/Certified item, I have a warm,
fuzzy feeling that it will do what it's supposed to do, have a reasonable
MTBF, and that under day-to-day circumstances, I won't have any
surprises.

At no time in my professional career (very large software systems in
aerospace) have I *EVER* had that feeling
with a COTS software or hardware system in a mission-critical environment.

"Bob Noel" wrote

What are the failure modes of these components? How will failures
and errors be detected and handled? How will component changes
be handled? How much will it cost to repeat the appropriate analyses
when various vendors roll part numbers? How will you determine that
the part hasn't changed when the vendor didn't change the part number?
(Don't laugh, I've seen an LRU no longer work in a particular aircraft
when
a chipset vendor changed a production process which ever so slightly
changed functionality but the vendor didn't change the part number).

And do you have any concept of what it would take to put a commodity
OS like windows into a safety-critical application?
All this and more. .

How about the displays necessary to be bright enough for easy viewing in
very bright situations? They cost twice as much alone, as the computers in
the price range he is suggesting on using for running the applications.

How about the hard drives? They need to be able to handle high altitudes
without (what is the proper term, here? ) hard drive platter crashes? (the
readers above the platter scraping the platters, instead of floating on a
layer of air slightly above the platters)
--
Jim in NC

"Bob Noel" wrote in message
news:ihatessppaamm-

And do you have any concept of what it would take to put a commodity
OS like windows into a safety-critical application?

I toured a Navy cruiser within the last several years that had Windows
running at various stations around the bridge.

*cringe*

-c

Gatt wrote:
I toured a Navy cruiser within the last several years that had Windows
running at various stations around the bridge.

Jeez. "Blue screen of Death" takes on new meaning.

--
Message posted via AviationKB.com
http://www.aviationkb.com/Uwe/Forums...ation/200709/1

On Sep 21, 3:27 pm, "Kloudy via AviationKB.com" u33403@uwe wrote:
Gatt wrote:
I toured a Navy cruiser within the last several years that had Windows
running at various stations around the bridge.

Jeez. "Blue screen of Death" takes on new meaning.

--
Message posted via AviationKB.comhttp://www.aviationkb.com/Uwe/Forums.aspx/aviation/200709/1

Yes, just ask the Iranian A-320 passengers...

On Sep 19, 12:31 am, Le Chaud Lapin wrote:
Hi All,

I am a student for my private license, and during my last ground
school session, I was having discussion about how glass cockpits might
be made cheaper by using commoditized components. For example, some
GPS units cost $1000's US, but a friend of mine help found a company
that made the most advanced GPS receivers around, and those devices,
including package, barely cost $400. Simpler receives are a lot
cheaper, some as low as $50US (http://electronics.pricegrabber.com/gps-
receivers/p/2003/form_keyword=usb+gps/rd=1) I'm not sure what the
differences are in receivers, but I would imagine that a "good" GPS
unit could be had for say, $500, in which case, that, coupled with a
conventional PC and software, should be able to do anything that the
fancier (Garmin, etc) units can do. Most importantly, that one PC
could work for many instruments simultaneously, and cost difference
should be huge . [Yes, I know, reliability, FAA
certification...yada...]

What shocked me was the purported cost of instruments compared to what
they could cost. A USB pressure sensor should not cost more than
$500, in my opinion. I guessed that the VSI might cost a few hundred
dollars US as a conservative estimate. My instructor and another
student stated that the cost is more like in the $1000's for a typical
instrument. Is this true? It's not that I doubt my instructor or my
fellow student. I just want to get an idea of how much these various
devices cost.

For a base reference, I would consider the standard instruments found
in Cessna 172.

All comments welcome,

-Le Chaud Lapin-

One big reason for the elevated cost is FAA certification. Another big
reason is that the equipment must be made to withstand the normal
demands of aviation, such as vibrations, temperature cycling,
interference etc.. In experimental aircraft you can install whatever
you like. Some manufacturers make good equipment but choose not to get
FAA certification for the cost. But that does not mean everything from
your local electronics dealer can be used. You mentioned GPS and
computers. Aviation GPS has RAIM, which is a signal integrity checking
system that warns the pilot when there are conflicting signals. Not
all computers work well in a cockpit unless they use solid state
drives. Normal LCD displays will stop working when it gets very cold,
or very hot. In fact they may not even work that well in a car if you
left them inside during summer and winter when temperatures can reach
extremes.

Le Chaud Lapin wrote:
Hi All,

I am a student for my private license, and during my last ground
school session, I was having discussion about how glass cockpits might
be made cheaper by using commoditized components. For example, some
GPS units cost $1000's US, but a friend of mine help found a company
that made the most advanced GPS receivers around, and those devices,
including package, barely cost $400. Simpler receives are a lot
cheaper, some as low as $50US (http://electronics.pricegrabber.com/gps-
receivers/p/2003/form_keyword=usb+gps/rd=1) I'm not sure what the
differences are in receivers, but I would imagine that a "good" GPS
unit could be had for say, $500, in which case, that, coupled with a
conventional PC and software, should be able to do anything that the
fancier (Garmin, etc) units can do. Most importantly, that one PC
could work for many instruments simultaneously, and cost difference
should be huge . [Yes, I know, reliability, FAA
certification...yada...]

I think we are already close to your request.

A Lowrance 2000c gives you terrain, airspace,
VFR chart, airports and frequencies in a very
nice little package for about 700 USD on discount.

These days, a GPS that gives you lat/long, ground
speed and heading is trivial. I can't imagine
the amount of work that must go into all the other
details of a nice aviation GPS. Plus the warm
feeling of having a Jep database in the unit.

What shocked me was the purported cost of instruments compared to what
they could cost. A USB pressure sensor should not cost more than
$500, in my opinion. I guessed that the VSI might cost a few hundred
dollars US as a conservative estimate. My instructor and another
student stated that the cost is more like in the $1000's for a typical
instrument. Is this true? It's not that I doubt my instructor or my
fellow student. I just want to get an idea of how much these various
devices cost.

For a base reference, I would consider the standard instruments found
in Cessna 172.

Check http://www.dynonavionics.com

Beautiful equipment at a reasonable cost.

All comments welcome,

-Le Chaud Lapin-

On Sep 19, 1:08 pm, Jim Stewart wrote:
Le Chaud Lapin wrote:
Hi All,

I am a student for my private license, and during my last ground
school session, I was having discussion about how glass cockpits might
be made cheaper by using commoditized components. For example, some
GPS units cost $1000's US, but a friend of mine help found a company
that made the most advanced GPS receivers around, and those devices,
including package, barely cost $400. Simpler receives are a lot
cheaper, some as low as $50US (http://electronics.pricegrabber.com/gps-
receivers/p/2003/form_keyword=usb+gps/rd=1) I'm not sure what the
differences are in receivers, but I would imagine that a "good" GPS
unit could be had for say, $500, in which case, that, coupled with a
conventional PC and software, should be able to do anything that the
fancier (Garmin, etc) units can do. Most importantly, that one PC
could work for many instruments simultaneously, and cost difference
should be huge . [Yes, I know, reliability, FAA
certification...yada...]

I think we are already close to your request.

A Lowrance 2000c gives you terrain, airspace,
VFR chart, airports and frequencies in a very
nice little package for about 700 USD on discount.

These days, a GPS that gives you lat/long, ground
speed and heading is trivial. I can't imagine
the amount of work that must go into all the other
details of a nice aviation GPS. Plus the warm
feeling of having a Jep database in the unit.

What shocked me was the purported cost of instruments compared to what
they could cost. A USB pressure sensor should not cost more than
$500, in my opinion. I guessed that the VSI might cost a few hundred
dollars US as a conservative estimate. My instructor and another
student stated that the cost is more like in the $1000's for a typical
instrument. Is this true? It's not that I doubt my instructor or my
fellow student. I just want to get an idea of how much these various
devices cost.
For a base reference, I would consider the standard instruments found
in Cessna 172.

Checkhttp://www.dynonavionics.com

Beautiful equipment at a reasonable cost.



Yes it is a very economical alternative, but not without some
compromises. Dynon needs airspeed as an input to stabilize its
reference systems. Other systems such as Blue Mountain use GPS as one
of the inputs. The ones that are truly inertial (ie not requiring any
inputs) are not in the same price range. So when comparing to the old
fashioned spinning gyros, one has to keep these differences in mind.