Speed failure indication
In case of a FAC failure or failure of a related data source all speeds computed by this FAC are inhibited and no longer displayed.
In the event of a FAC information failure all the speed scale displays are cleared to avoid any confusion and a red SPD LIMITS failure warning message appears.
This message flashes during a few seconds then remains visible until the system is switched manually over to another source (FAC2).
If the SPD LIM or the SPD warning is displayed on one PFD only, switching to the other FAC and its related data sources (primarily its ADC) is possible by means of the ADC INSTRUMENT TRANSFER pbs.