Peter, we have answered !
New (WAAS) antennas, new software, and that’s all (for Cessna).
The main point is that there is no modification to wiring to perform.
It’s probably getting hold of the new software that will be a challenge. For a Cessna, you have to buy the new card from Textron, not from Garmin. In the case of a Txi upgrade, the new card was about $5.5K
Txi is another beast.
0563.36 (WAAS non NXi) software on Cessna is rather like 0.5k$
https://www.airpowerinc.com/3931531-5
Unless I’m wrong ?
PetitCessnaVoyageur wrote:
0563.36 (WAAS non NXi) software on Cessna is rather like 0.5k$
That’s much better than I expected.