Garmin GTN 625 Pilot's Manual page 332

10.7.6
Foreword
Alerts are issued when flight conditions meet parameters that are set within
HTAWS software algorithms. HTAWS alerts employ either a CAUTION or a
Getting
Started
WARNING alert severity level. When an alert is issued, visual annunciations
are displayed. Aural alerts are simultaneously issued. Annunciations appear in a
Audio &
Xpdr Ctrl
dedicated field in the lower left corner of the display.
Annunciations are color-coded according to the HTAWS Alert Summary
Com/Nav
table. Pop-up terrain alerts occur if an HTAWS alert is activated while not on the
FPL
HTAWS page. There are two options when an alert is active.
To acknowledge the pop-up alert and return to the currently viewed page:
Direct-To
Touch the Close key.
Proc
To acknowledge the pop-up alert and quickly access the HTAWS Page:
Touch the ENT key.
Wpt Info
NOTE: To further capture the attention of the pilot, HTAWS issues aural
Map
(voice) messages that accompany visual annunciations and pop-up alerts.
For a summary of aural messages, refer to the HTAWS Alert Summary table.
Traffic
NOTE: HTAWS Caution Alerts are displayed as constant black text on a
Terrain
yellow background; HTAWS Warning Alerts are displayed as constant white
text on a red background.
Weather
10.7.6.1
Nearest
The unit will issue terrain alerts not only when the aircraft altitude is below
the terrain elevation but also when the aircraft is projected to come within
Services/
Music
minimum clearance values of the terrain. This alerting, called Forward Looking
Terrain Avoidance (FLTA), is also provided for obstacles.
Utilities
The FLTA functionality looks ahead of the aircraft using GPS position
information and the terrain and obstacle databases to provide alerts when
System
the predicted flight path does not clear the terrain or obstacle by the required
Messages
clearance. The amount of clearance required varies depending on position
relative to airports and heliports, in order to reduce the occurrence of nuisance
Symbols
alerting.
Any threat locations are depicted on the display. There are 2 levels of severity
Appendix
for FLTA alerts. They are cautionary (amber) and warning (red) in nature and are
described in further detail below.
Index
10-44
HTAWS Alerts
Forward Looking Terrain Avoidance
GTN 625/635/650 Pilot's Guide 190-01004-03 Rev. P