Premature Descent Alerting - Garmin G500 Pilot's Manual

4.3.5.4

Premature Descent Alerting

A Premature Descent Alert (PDA) is issued when the system detects that the
aircraft is significantly below the normal approach path to a runway.
PDA alerting begins when the aircraft is within 15 NM of the destination
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
the final descent, algorithms set a threshold for alerting based on speed, distance,
and other parameters.
700
600
500
400
300
200
100
Runway
Threshold
PDA and FLTA aural and visual alerts can be manually inhibited. Discretion
should be used when inhibiting TAWS and the system should be enabled when
appropriate. When TAWS is inhibited, the alert annunciation "TAWS INHB" is
shown on the PFD and MFD (Figure 4-16).
190-00601-02 Rev. J
1 2 3 4 5 6
Distance From Destination Airport (nm)
Figure 4-19 PDA Alerting Threshold
Garmin G500/G600 Pilot's Guide
TOC
PDA Alerting Area PDA Alerting Area
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Cover
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