pilotnik.
RAIM prediction is used preflight, and if the RAIM prediction shows that RNP is not available enroute (depending on the procedure) or on final destination, legally, the flight cannot be planned to use the RNP procedure. (especially AR)
That is the simple fact of the flight plan, if RAIM prediction shows not available, you cannot plan to use the procedure.
We have been trying to change this, if conditions change enroute, but the criteria prevails.
Conversely, if RAIM prediction shows that it is avail, and during flight RAIM goes downhill on you, you cannot use the procedure...
We are LPV capable, use SBAS and have no requirement to check RAIM because the integrity is done through the SBAS signal
I hope you are kidding.
In general, reading through this thread on RAIM, the explanations and reasonings provided are sad, very, very sad.