And people fit 2x G5 thinking they get 2x the redundancy…
A very good and important post Peter!
Even the Airbus, using triplicate systems, having been designed by separate programmers teams, was prone to severe bugs, even freezes… and you bet those screens are slightly more expensive than a G5 
Pirep: I now have close to 1K hours flown behind G5.
A few years ago I suffered a failure, in VMC, in prolonged severe turb, whilst closely circumnavigating some cells in Southern Sweden. The G5 attitude stopped working and the alert ALIGNING was presented… When the shaking subsided the G5 recovered.
I reported the event to the manufacturer, but couldn’t provide hard data since my mini SD card was nice and safely at home… It seems I wasn’t the only one reporting the problem, and a few revisions later, is hopefully resolved.
Haven’t had any failure since, though I haven’t encountered similar conditions since.
It also explains the presence of the AV-20S on my dual G5 panel…
Ultranomad wrote:
I vagurely remember reading some review of sex toys, which awarded Harley the first place among vibrators in terms of girl’s satisfaction.
LOL! That goes with the old aviation myth that girls used to like the old prop liners better for that reason. I’ll call it a myth as some of this certainly would apply to our GA airplanes too but nobody has really supported that kind of effect to my knowledge.
It’s only a matter of time before someone here proposes a group test of that theory 
Even the Airbus, using triplicate systems, having been designed by separate programmers teams, was prone to severe bugs, even freezes… and you bet those screens are slightly more expensive than a G5
You know the funniest bit of this morning’s bug? It would have also blocked firmware upgrades in the field, if the file size was bigger than 256k So one could not even have fixed affected products without them being returned to factory.
And this can happen to anybody.
After chasing issues with the KI 256 for a while and having problems with my G5 HSI, I’m getting an Aspen Pro Max installed in March. Haven’t really considered keeping the 256 in another location. In my instrument check it decided to lose its mind for the first time in weeks, and has been perfect since. I was pretty OK flying the rest of the test including the approaches on the backup instruments.
What problems with the G5 did you experience?
I wonder if this G5 issue in severe turbulence also manifests itself in external AHRS equipment like the Stratus 3, which I carry as backup. Again, in several hundred flying hours in our club no issues (other than the teething problems I mentioned earlier) have been reported.
Snoopy wrote:
What problems with the G5 did you experience?
A few problems with calibration, and the battery died after <100 hours.
Pirep – Twin G5’s for about 3 years and 300 hours. Some severe turb and all OK. I love the G5’s. If the top G5 fails the bottom one instantly turns into a AI (but I have no idea if that would work if the top one got seriously confused as mentioned in the posts above)
When the G5’s were installed I had to keep the old Vacuum system to drive the 40 year old Piper/ Altimatic Autopilot. Originally, I was determined to junk the vac system and I had a long term plan to change the autopilot to a Garmin GFC500 – I liked the envelope protection, the straight and level switch etc.
In 7 years, my Piper “Apollo” age Autopilot still has never really missed a beat (except once a dodgy plug knocked during an Annual – so a Maintenance Induced Failure)
I hardly notice the repositioned vacuum driven AI now mounted a little lower down. I now think I’ll keep this. Perhaps if the GPS antenna was struck by lightening and both G5’s went up in smoke the old AI might be very handy?
Edit – I installed the OAT probe 12 months later for winds aloft – absolutely brilliant.
Snoopy wrote:
What problems with the G5 did you experience?
For the first few iterations of the firmware, the horizon was often quite inaccurate (it would show a bank of up to 10 degrees in straight and level flight). This was despite good air data and GPS reception. Many of the first series of firmware updates had a changelog item “improved attitude calculation”. With the current version of the firmware I’ve not seen any problems with the attitude display, even when towing gliders (where there’s typically only about 30 seconds from startup to applying power for takeoff and no prolonged taxi). With the original firmware versions, a short taxi would often leave the attitude display showing a 20 degree bank on takeoff when the wings were actually level!
The air data sensors on mine also failed after about 2 years, I sent it in for service, the replacement unit has not had any issues.
That sounds rather like the Aspen EFD “software fixes” for the OAT reading several degrees off.
