I've noticed a lack of subject matter on the loss of SBAS as compared to RAIM.
In the ACS there is mention of RNP, SBAS (WAAS), and RAIM, which are all related, but the available content for RAIM and WAAS is much heavier on losses of RAIM than losses of WAAS.
This really became apparent to me when I was searching Garmin G1000 documentation to find annunciations regarding the loss of SBAS, and I noticed that there essentially isn't one other than "APR DWNGRADE" which loosely translates in the manual to, "you lost WAAS capability".
However, the loss of RAIM has a much more clear and direct annunciation, "RAIM UNAVAIL": that needs no translation and is immediately clear that you've lost RAIM.
Why would Garmin not have an "SBAS UNAVAIL" or "WAAS UNAVAIL" annunciation in the same manner as they do for RAIM? It's almost as if the industry as a whole largely discounts the possibility of SBAS failures.
Here's a list of G1000 NAVIII Annunciations
Here is where WAAS is mentioned in the annunciation list. Note that the column on the left is the annunciation displayed on the flight deck, but the column on the right is the manual's referenceable extrapolation:
Notice above that neither of the flight-deck-displayed texts on the left which have extended explanations on the right that include "WAAS" also contain "WAAS" or "SBAS" in their in-flight annunciation messages' texts.
Here is where RAIM is mentioned in the annunciation list:
Notice above that the flight-deck-displayed text does contain "RAIM" (twice) for a RAIM loss.
I included the above information to demonstrate my point, and I essentially have three closely-related questions:
Why is Garmin so indirect about the loss of SBAS in their annunciations?
Why do pilots not also perform SBAS predictions like they do for RAIM?
Why is the loss of RAIM given so much more emphasis in training than the loss of SBAS?