118 to the flight management and or auto pilot systems 106 in a preferred embodiment the switch unit 202 is controlled by the processor system 114 alternatively the switch unit 202 may be controlled by the by another system device such as but not limited to the airborne gnss device 104 the switching functions performed by the switch unit 202 may be implemented with any suitable type of electronic solid state or firmware type switching device or means commonly employed in the art for example a processor based switch unit 202 would be implemented using a combination of software and firmware using components and methods commonly employed in the art of switching electrical devices in an alternative embodiment both the sbas integrity information 108 and the gbas integrity information 110 are monitored in the event that the sbas integrity information 108 indicates that the gnss location information has been corrupted a time interval corresponding to the sbas integrity information 108 here the exemplary thirty seconds is used thus if the sbas integrity information 108 indicates a corruption the predictive location information determined by the delay kalman filter 118 is based upon a time interval associated with the sbas integrity information 108 alternatively in the event that the gbas integrity information 110 indicates that the gnss location information has been corrupted a time interval corresponding to the gbas integrity information 110 here the exemplary six seconds is used thus if the gbas integrity information 110 indicates a corruption the predictive location information determined by the delay kalman filter 118 is based upon a time interval associated.