In article , Doug Vetter
wrote:

They can get away with using NT because the software in the
avidyne systems does not cause or contribute to a major hazard.

The way the rep put it, the Feds believe NT is a known quantity, so it
speeded the process of necessary approvals. The rep also thought it was
nice that he was able to connect a monitor to the back of the unit and
configure it like any other windoze application.

Windows of any kind (even stripped down for this application) is still
far inferior to a real-time version of linux, but what do the Feds
know....they're paper pushers...not engineers.


I didn't phrase it correctly. I should have said that the software
in the Avidyne system could not cause or contribute to a major
hazard due to a failure to provide the function. That is, the
loss of the system functionality would not be a major hazard.
While no one at Avidyne will say exactly how they protect against
hazardly misleading information (HMI), I believe that some hardware
monitor is in place to protect against HMI rather than depending
on windows NT to assure the correct functioning of the software.

Sure, the Feds believe NT is a known quantity. But don't let
that confuse you. No Windows-based software system has the software
portion certified to DO-178B level C. At best, it's only Level D, which
is trivial to do, even for Windows.

--
Bob Noel