Originally Posted by
pilotnik
Let me tell you why I am asking this. I am an ATCO and there was an RAIM unavailability prediction over the airport for a short time. Nevertheless, during this very time, TWO aircraft requested RNP approach. Both were informed about the lack of RAIM and even though they insisted on the approach.
Very simply, the avionics will have indicated if they were able to carry out the procedure.
They may have been equipped with baro aiding which substitutes for one satellite or they may have been equipped with SBAS in which case RAIM is irrelevant. Even if they lacked either it is still quite feasible that the approach and the flight planning were totally legit The single piece of evidence “there was a predictive RAIM unavailability over the airport for a short time” is not in itself evidence of non compliance.