190-00728-04 Rev. A
Embraer Prodigy® Flight Deck 100 Pilot’s Guide
409
HAZARD AVOIDANCE
Figure 6-106 TAWS-A Page Menu
TAWS-A ABNORMAL OPERATIONS
TAWS-Acontinuallymonitorsseveralsystem-critical itemssuchas databasevalidity,apandlandinggear
position,radaraltimeterinput,andGPSstatus.
IfnoGDUcontainsTerrain,AirportTerrain,andObstacledatabases(orthedatabasesareinvalid),theaural
message “TAWS System Failure”isgeneratedalongwiththe‘TAWSFAIL’alertannunciation.
TAWS-Arequiresa3-DGPSnavigationsolutionalongwithspecicverticalaccuracyminimums.Shouldthe
navigation solution become degraded or if the aircraft is out of the database coverage area, the annunciation
‘TAWSN/A’isgeneratedintheannunciation windowandonthe TAWS-APage.Theaural message“TAWS
Not Available”isalsogeneratedifairborne,and someTAWS-Aterrainalertswillnotbeissued(Table6-12),
whileGPWSalerting (whichare notdependenton GPSposition) willcontinueto operate. WhentheGPS
signalisrestoredandthe aircraftiswithinthedatabase coveragearea,theauralmessage“TAWSAvailable”is
generated.
TAWS-Aalsorequiresradaraltimeterinput.Shouldthe radaraltimeterinputfailorbecome degraded,the
annunciation‘GPWS FAIL’isgenerated in the annunciation window and on the TAWS-APage.  The aural
message “GPWS System Failure”isalsogenerated.The‘GPWSFAIL’annunciationwillalsooccurifbothGPS
altitudeandbarometricaltitudeareunavailable.If onlytheGPWSsystemhasfailed,GPWS-based alertswill
notbeavailable(Table6-12),whileotherTAWS-Aalertingremainsunaffected.