Recently, J. Severyn posted:

"Neil Gould" wrote:
Recently, J. Severyn posted:

"Neil Gould" wrote in message
et...
Yesterday, I attended a 4-hour seminar on the G1000 presented by

snip

I understand, and it appears that this was done. On the one hand,
this system isn't all that complex; rather than feed numerous inputs
into a single interpreter module, which might result in the kind of
event you're anticipating, each module is a physically separate
piece of hardware that feeds its results to the integraged display.
There is also redundancy built into some modules (multiple
components doing the same job), and any ambiguities are either
resolved by a "vote of the majority" or failed, but won't result in
a system-wide reboot.

I understand. But the integrated display might be the culprit.

I don't think that's possible. There is no provision for the display
system to reboot the hardware; that just isn't done via software, or even
by physical switches located on the display unit(s). The display unit(s)
can't turn on or off the individual modules either, so a software glitch
of any kind -- or even total failure of the display -- isn't able to be
the cause of a system-wide reboot.

The
individual LRUs might be acting properly and feeding data to the
display system. If the display system (hardware or software) does
not properly handle the exceptions, then lots of unintended things
can happen. Software patches, compiler errors etc. only make the
testing combinations all the more difficult.

I understand, and in a type of arrangement where sensor outputs are being
interpreted by centralized CPU, what you describe might be an area of
concern. But, the G1000 is not that kind of system. Each module is its own
complete computing system, the integrated display merely reports the data
provided by the modules. When the data from modules conflicts and can't be
resolved, the centralized display can disable that module's content *on
the screen*, it can't shut the module down.

In any case, a pilot has got to be able to keep the dirty side down
using the backup steam guages.

The backup steam gauges are completely separate from the G1000, as is the
autopilot and the comm (another reason that I suspect NW_Pilot's problems
are related to the loss of power). In fact, the 2-axis autopilot has its
own turn coordinator mounted behind(!) the panel, and will fly the plane
even if the G1000 is turned off.

Neil