[frankd]

Can the WAAS GPS data in the 45R be used as the position source for the G3X system?

 

[mburch]

Quoting from the installation manual: (section in 2.1.1.8 in revision AV)

GPS data is used for ADAHRS performance monitoring, so at least one source of GPS data is required. This requirement can be met by installing a GPS 20A, or by connecting a GPS antenna to at least one GDU GPS receiver. A GTX Series Transponder with built-in GPS, or a GNX 375 connected to the system will also satisfy this requirement. In a system with multiple GDU displays, additional GPS antennas may be connected to the other displays for redundancy, if desired.

 

[Walt]

Yes, but correct me if I'm wrong, the above can only be used for aiding or an ADS-B position source, not as a position source for navigation.
I've never tried it, but that has been my understanding.

 

[mburch]

Yes, but correct me if I'm wrong, the above can only be used for aiding or an ADS-B position source, not as a position source for navigation.

I thought so too originally, but later came to understand that this is an allowed combination (many Cub Crafters airplanes are like this).

 

[Longez]

Yes, when I watch the GPS page on the GDU 4XX after system power-up, it starts with the G5 GPS (fastest to get a good fix), then switches to the GDU 4XX internal GPS, then ends up using the GNX 375 GPS for the remainder of the flight.

I had a GTX 345 with internal GPS installed before I installed the GNX 375, and it would end up using the GTX 345 GPS as the primary source for the entire flight when available.