It really boils down to finding the single points of failure. In the
Cessna piston G1000 package the AHARS and ADC are the only single
boxes that matter in the system.

I agree that a AHARS or ADC failure are the scary ones in IMC (AHRS more than ADC)
It would be nice to be able to simulate thoose failures for training.
In the 182 I'm flying the ADC and AHRS are on the same CB,
if you pull the CB you loose Mode C as the transponder uses the ADC to know altitude.

One can use the G1000 PC simulator to see what a failure looks like, but it
does not really help you test your scan and ability to navigate and control the aircraft in IMC.


Paul