Re: REFLECTOR: SNF & Panel

[Matt Harrop <matt@mattcave.ca>]

My XL kit is on a truck as I type, so I'm probably a year away from
actually deciding on the instrument and avionics complement for aircraft.
Here are some of my ideas.

Many people have mentioned standby vacuum as essential for IFR operation.
While I agree with the reasoning, I think the conclusion is somewhat
flawed.  Since the fact is that if you lose your AI in IMC you will
probably die, I plan to install an electric AI as a backup to the vacuum
driven instruments.  Having a vacuum gyro and an electric gyro means that a
single failure can't take them both out.  True paranoia might actually lean
towards a separate backup battery for the electric AI, to account for
simultaneous vacuum and electrical failures.

For avionics, a Garmin GNS430 will form the core of the system.  I'm not
yet decided between a GPS/COMM or a NAV/COMM to backup the big Garmin.  I
like the King KX-125 because it's fairly cheap, and has a built in OBS/CDI
which will save an instrument hole.  On the other hand, something like a
GNC250XL isn't much more expensive than the King, and in the event that the
GNS430 goes south, I'd probably rather have a GPS than a VOR.  Having two
GPS on the panel obligates me to maintain two data subscriptions, which
isn't something I'd like to do.  

Any thoughts on either of these issues would be appreciated.

Regards,
matt