Altitude data source for garmin 400w

[Richard Connell]

Thanks bob
Yes that's my understanding. That is the realm of FMS etc.
we don't even get LNAV + V here and likely never will.

Is the airdata required for LNAV+V or LPV over there? Or is I just a function of WAAS ( which we missed out on too :-( )

[BobTurner]

lnav+V is just a Garmin thing, the GS is advisory only, it's still an LNAV non precision approach. For LPV we just need WAAS, no air data. It used to be that pre WAAS some boxes used baro data as part of their integrity check.