in over 1000 hours flying the LIVP and Chelton combo I have had:

 

1.  a total electrical failure (all screens go immediately dark-- not good when you are IMC over Jackson Hole). Three mechanical peanut gauges bought me enough time to recover. I had tow alternators at the time but it was a battery failure that took the entire system down.

 

2.  an AHRS go bonzo without any EFIS cautions on an IMC flight creating some confusion as to what was happening. Comparing the EFIS to the mech gauges and TC helped sort things out. The AHRSA went back to Crossbow.

 

3.  a heading failure with no EFIS announcements caused by too much steel near the AHRS (towbar). Don't place any steel within feet of your magnetic flux gate.

 

4. I have also had two occasions where a stray electron took down the entire Air Data and Engine display . One due to a TIT probe failure-- I was the beta tester there and the other was a short forward of the firewall coming in through the EAU taking the EAU out of the loop.

 

Although IMC occupies only 10-15 % of my total flying-- it is during that time that the solo pilot can ill afford a primary system instrument failure. A robust backup system is in order. The days of having a vacuum failure fly the TC are over for most of us. Consider how you are going to diagnose a failure -- and not all are announced by the EFIS and how are you going to get home.

 

Consider how you are going to fly the airplane with no electrical power or with every screen dark or so screwed up nothing electronic is usable. It will happen-- and not in clear blue and 22.

 

Jeff

(got the tee shirt)