G5/GFC500 with IFD series

In conversation with avionics shop in the southwest, a install was planned to install a G* G5 electronic flight instrument as well as a GFC500 autopilot in my Bonanza.

The G5 is called out in the IFD540 install manual, as is the G500 and Txi PFD, and since the GFC500 is driven by the G5, we thought all legalities fulfilled.

_But_

The autopilot GFC500 STC lists only G* navigators.  The Avidyne series is not called out in the autopilot STC, so STC requirements would not be met.

Moreover, the avionics manager was told by G* engineering directly that any GFC500s driven by IFDs do not meet the requirements of the STC and are not certified.  The manager told me that just having a 337 only documents the change made to the aircraft, it does not provide certification.

I suppose a field approval is possible, but...

Perhaps tech support doesn't know about such a document.  They sent me the ICA for the IFD which doesn't mention that.

If anybody has such a document, (and Avi is still looking), please let me know.

I wonder if that excerpt has enough «legal weight» to support the certification of the GFC500/IFD5XX combo?

You won’t have a plug&play IFD installation if you want WAAS since you‘re substituting the IFD for a non-WAAS GNS. You‘d have to make the same changes though to upgrade GNS to WAAS (mostly antenna-related).

First off - it all works perfectly and is really a great system - way better than the many other types of setups that I have first hand experience with because I fly and teach for a retirement job.

All the installations were done with the oversight of my mechanic and were approved by three different radio shops that are all authorized dealers for all the pieces. NO PROBLEMS with installation nor with approval. The legality is addressed by Avidyne in their installation manual where they document the concept of direct replacement for 430/530 devices - approval that the other folks are not happy about and won't recognize, but is fully legal and compatible none the less.

Find a shop that knows what is what and what they are doing - and preferably has done the installs of these three pieces before. It is not a problem to do what you want (including transition to the WAAS capability of the Avidyne stuff). You may have to change your GPS antenna to a WAAS-certified unit. You do NOT have to have antenna for the G5s and their internal antennae will almost certainly work for backup (be certain the shop tests this before they sell you a "required" second antenna).

You will be very pleased with the performance of these three interconnected components.