Airbus Industrie Undifferentiated or Other Model
Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural MEL / CDL
Procedure; Manuals; MEL
I am concerned that Placard XXXXX does not accurately describe the flight planning restrictions associated with a single GPS inoperative on the Airbus. It appears to me that neither RNAV (GPS) nor RNAV (RNP) approaches may be conducted in this condition; but the placard only prohibits RNAV (RNP) approaches (which are not authorized on the Airbus fleet anyway). I discovered this discrepancy prior to the point of dispatch; and my flight is dispatched safely and legally.Per the Flight Manual 'RNAV (GPS) and RNAV (RNP) approach procedures require WGS-84 coordinates and GPS PRIMARY.';Per the Flight Manual 'GPS PRIMARY requires the following: (2) operational FMGCs; (2) operational GPS systems; and GPS PRIMARY displayed on both MCDUs on PROG page.'Per these guidelines; we do not have GPS primary due to only (1) operational GPS system. Since we don't have GPS primary; we can no longer conduct RNAV (GPS) nor RNAV (RNP) approaches. This is further supported in the ICAO 2012 QRG which states 'RNAV (GPS) approaches require both GPS'.This is a safety concern due to the fact that without doing the additional research a flight could be unsafely and illegally dispatched to a station based on an RNAV (GPS) approach. Alternatively; if the placard is correct and RNAV (GPS) approaches may still be conducted; then the Flight Manual and ICAO 2012 QRG references should be clarified in order to prevent further confusion.
Air carrier Dispatcher reported the MEL restriction for a single GPS inoperative does not accurately describe the flight planning restrictions.