Premature Descent Alerting - Garmin GTN 750 Pilot's Manual

Foreword
Getting
Started
Audio &
Xpdr Ctrl
Com/Nav
Table 11-4 FLTA Alert Minimum Terrain and Obstacle Clearance Values
FPL
During final approach, FLTA alerts are automatically inhibited when the
aircraft is below 200 feet AGL while within 0.5 NM of the approach runway or
Direct-To
below 125 feet AGL while within 1.0 NM of the runway threshold.
11.3.8.4
Proc
A Premature Descent Alert (PDA) is issued when the system detects that the
Charts
aircraft is significantly below the normal approach path to a runway.
PDA alerting begins when the aircraft is within 15 NM of the destination
Wpt Info
airport and ends when the aircraft is either 0.5 NM from the runway threshold
or is at an altitude of 125 feet AGL while within 1.0 NM of the threshold. During
Map
the final descent, algorithms set a threshold for alerting based on speed, distance,
and other parameters.
Traffic
Terrain
Weather
Nearest
Music
Utilities
System
PDA and FLTA aural and visual alerts can be manually inhibited. Discretion
Messages
should be used when inhibiting TAWS and the system should be enabled when
appropriate. When TAWS is inhibited, the alert annunciation "TER INHB" is
Symbols
shown.
Appendix
11-16
Index
Flight Phase
En Route
Terminal
Approach
Departure

Premature Descent Alerting

Figure 11-13 PDA Alerting Threshold
Garmin GTN 725/750 Pilot's Guide
Minimum Clearance Altitude (feet)
Level Flight
700
350
150
100
Descending
500
300
100
100
190-01007-03 Rev. B