Garmin GNC 420AW GPS Receiver User Manual


  Open as PDF
of 220
 
2 - NAV PAGES
48
190-00356-00 Rev E
Premature Descent Alerting (PDA)
TheTERRAINsystemissuesaPrematureDescent
Alert(PDA)whenthesystemdetectsthattheaircraft
is significantly below the normal approach path to a
runway.
PDA ends when the aircraft is either:
• 0.5 NM from the runway threshold
OR
• is below an altitude of 125 feet AGL while
within
1.0 NM of the threshold.
CAUTION — The above annunciation and pop-up
terrain alert are displayed during a PDA alert.
PDA Severity Levels
TERRAIN Failure Alert
The TERRAIN system continually monitors
several system-critical items, such as database validity,
hardware status, and GPS status. Should the system
detect a failure, a message is annunciated “TERRAIN
has failed”.
“TERRAIN has failed” message
Terrain Alerts







(EIGHT!BOVE4ERRAIN&EET
$ISTANCE&ROM$ESTINATION!IRPORTNM
              
0$!!LERTING!REA0$!!LERTING!REA
2UNWAY
4HRESHOLD
Premature Descent Alerting (PDA) Threshold
 previous next