Greetings
RNP 0.3 is the smallest for Airbus regardless of its FMS, now RNP is the budget of all systems involved, and to start with we should begin with the FG (flight Guidance, or Auto-pilot if you will) and until today nothing have been done, I suggest everyone to check the AFM (airplance Flight Manual) and verify what is the smallest RNP the Airbus is certified for, and with what type of sensors, i.e., DME/DME, GPS, ILS....
