Cost of Cockpit Instruments

Recently, Le Chaud Lapin posted:

On Sep 22, 1:15 pm, (Blanche Cohen) wrote:
Since when are software people licensed?

The products would have to be licensed.

Who does the licensing?

Same agency that approves products containing software in say, Boeing
777.

Well, now we're right back where we started, unless you think that this
process results in cheap cockpit components for a 777. ;-)

What are the exams? What is the followup to maintain it?

Oh, I see what you mean. The products would be certified, not just
the people who make them.

Hmmm. When I was an inspector at a manufacturer of aircraft engine
components, I had to be certified (just as the welders, lathe operators,
etc. had to be), or the products wouldn't be certified. How do you get
around that by using just anybody to manufacture the products?

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.

I can at least sympathize with the reservations that you and others
have about using COTS components (thanks, that's term I was looking
for). However, I once went to the dentist to get XRAY's by fancy new
machine that moves in an arc around entire face, and it malfunctioned
and started to crush my skull until dentist ran in and stopped it.
There is also that minor matter of Space Shuttles blowing up every few
years, despite being undergoing what is arguably one of the most
rigorous certification processes around.

The dentist's XRay machine was either set up incorrectly (perhaps by an
uncertified person?), or operated improperly. As for Shuttles, by and
large they are experimental crafts with many possible points of failure.
The risks are known and willingly undertaken by the participants, just as
are the fliers of experimental aircraft and drivers of experimental
vehicals (racing comes to mind).

The point is that I that think that the "beware the danger of COTS"
attitude is too extreme for the actual risk involved. There is always
some risk.

The general public are not willing to take such risks, nor should they be
subjected to them unknowingly. The recent recall of toys and baby
furniture underscores this last point. If I'm not flying an experimental
plane, I don't want the same risk levels as those that do. And, if I *am*
flying an experimental plane, I'd want good knowledge of what makes it
experimental. In the case that you're creating, it would be uncertifiable
components in an otherwise normal aircraft. Like Blanche, that would make
me rather uncomfortable in some flight conditions.

So I think the same thing could happen in aviation. There is a trade-
off between pain and pleasure of assumption. There is probably a
point where the cost would be so low from using (well-engineered) COTS
components that the risk of using them is superseded by the value that
they would bring.

How would one know if COTS units were "well-engineered", except by trial
and error? Take, for example, the recent problems with the certified G1000
(see other topics about this). The failures were attributed to some
supplied components in an otherwise "well-engineered" design. Now, IMO, if
the design was all that well-engineered, either those units would have
failed on final inspection (the preferable outcome) or the design would
have tolerated the components and operated properly without problems. Take
the certification process out of the equation, and who knows what one
would get?

Well, I have an idea of what one would get. As one who has bought and
built many computers over the years (I build them when my requirements are
more stringent than COTS can deliver), I can tell you that all brands of
either full systems or basic components are not of equal quality. The same
would be true for COTS cockpit instruments.

This is true for non-critical components in an aircraft, and might be
true for many critical components.

I seriously doubt it.

Neil