I replaced my vacuum DI with an AV30C, locked to DI function as per the manual. Had severe drift issues on the DI initially and did not trust it.
Installed the AVMAG magnetometer to fix the drift issue, but this did not help much. Decided to start the setup from scratch and follow the installation manual religiously - this fixed all problems and now my DI is rock solid! I cannot stress enough how important it is to follow the manual exactly and to as high precision as possible. I think I lot of installers neglect this part and it is probably to blame for a lot of the heading drift issues people see. The order one executes the setup is also crucial. I now wonder if I even needed the AVMAG, but to be honest, it performs like a slaved system now so I am pretty happy. (I know it is not certified as a slaved system, only aiding, but I have not had to adjust the DI for the last 4 flights).
I fly it IFR with no issues and feel totally comfortable relying on it. I do not have a GPS hooked up to it, but I do have the TailbeaconX paired with it, so I get GPS ground speed and track. The track seems pretty solid also.
I used to fly double G5's all the time and yes, they are great - but I really love my AV30C and do prefer the layout. The only think I would love to see added is glideslope, but even without that, I am seriously considering adding another AV30C to replace my vacuum AI.
Only two things have stopped me so far: I want to remove the legacy analog VSI, but the AV30C is not certified as primary VSI function (even though I find it much better than my analog VSI and never use it anymore, relying only on the AV30C VSI during en-route as well as approaches) - the other being that it does not have glideslope indication...
Therefore the GI-275 is still a candidate, but I would much rather have the AV30C if Uavionics can at least promise future firmware upgrades to bring glideslope and primary VSI to their unit.
Mooney M20E Super 21 (serial 805)
