"Jim Logajan" wrote in message
.. .
Is the same model artificial horizon designed decades ago still
manufactured today?

Do people repair mechanical gauges or simply replace them when they stop
working?

In a lot of cases, it's not so much if the item can be repaired, but whether
it is cost effective given the shop rate for the repair guy... If it wasn't
for the added cost (that gets passed on to us, of course) of FAA
certification, it would probably be cheaper for most items to be replaced
instead of repaired... After getting burnt on radio repairs a couple of
times for my old Narco, I replaced it with an MX-11 like was in my other
radio slot... With repairs to the Narco running a few hundred dollars a pop,
I could have bought the MX-11 with the money that I wasted on the Narco
repairs... Since I still ended up buying the MX-11, all that money was
wasted... A MX-11 runs around $900 these days and installation is just a
slide in replacment for the Narco that it replaces and as such, you don't
need an A&P or avionics shop to do the replacement... If it wasn't for the
cost of FAA certification, I suspect that the MX-11s might approach the cost
of CB radios... It's not unreasonable to think that their price might drop
to the $100-200 range... At that price, repairs start getting the same as
the cost of a new radio, so it's more unlikely that someone would choose to
repair the item... Since the newer circuit boards are less component
repairable, technicians are more likely to just be replacing a complete
subassembly board instead of troubleshooting down to a component level...
This saves some time (i.e. money) in the troubleshooting stage, but it
increases the price in the repair parts stage...

Personally, I'm not a big fan of the one system does everything approach in
some of the glass panels... I have no problem with mechanical gauges being
replaced with electronic gauges, but I would prefer for them to be
independent, possibly communicating to some other system through some sort
of standard interface... At Rockwell, many of their new systems were
communicating via TCP/IP packets... I kind of liked this approach... It
seemed rather simple and elegant... A device would have a particular IP
address and port number associated with it... You could send information to
that device or retrieve information from it as appropriate... For a
non-compliant device, you could just design a TCP/IP interface to the device
that translated from the proprietary device information format to the TCP/IP
format...