
2 - NAV PAGES
48
190-00356-00 Rev G
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!BOVE4ERRAIN&EET
$ISTANCE&ROM$ESTINATION!IRPORTNM
0$!!LERTING!REA
0$!!LERTING!REA
2UNWAY
4HRESHOLD
Premature Descent Alerting (PDA) Threshold
Summary of Contents for GNS 400W
Page 1: ...Pilot s Guide Reference 400W Series...
Page 10: ...INTRODUCTION viii 190 00356 00 Rev G Blank Page...
Page 70: ...2 NAV PAGES 60 190 00356 00 Rev G Blank Page...
Page 92: ...4 FLIGHT PLANS 82 190 00356 00 Rev G Blank Page...
Page 126: ...5 PROCEDURES 116 190 00356 00 Rev G Blank Page...
Page 158: ...7 NRST PAGES 148 190 00356 00 Rev G Nearest Airspaces Blank Page...
Page 218: ...APPENDIX D Index 208 190 00356 00 Rev G Blank Page...
Page 219: ......