Introduction - Garmin GTN 625 Pilot's Manual

10.5 TAWS-A (Optional)
10.5.1

Introduction

NOTE: TERRAIN, TAWS-A, TAWS-B, HTAWS, or HTERRAIN PROXIMITY
functionality will be available via the Terrain page, depending on the
installed hardware and configuration. HTAWS or HTERRAIN PROXIMITY
are available in software version 4.00, or later. TAWS-A is available in
software version 5.00, or later.
NOTE: The data contained in the TAWS databases comes from government
agencies. Garmin accurately processes and cross-validates the data but
cannot guarantee the accuracy and completeness of the data.
TAWS-A (Terrain Awareness and Warning System - Class A) is an optional
feature to increase situational awareness and aid in reducing controlled flight
into terrain (CFIT). TAWS-A provides visual and aural annunciations when
terrain and obstacles are within the given altitude threshold from the aircraft.
TAWS-A satisfies TSO-C151c Class A and TSO-92c requirements for
certification.
Class A TAWS requires the following components and will not work properly
without them:
• A valid terrain/obstacle/airport terrain database
• A valid 3-D GPS position solution
• Valid flap and landing gear status inputs
• A valid radar altimeter
TAWS-A uses terrain and obstacle information supplied by government
sources. Terrain information is based on terrain elevation information in a
database that may contain inaccuracies. Individual obstructions may be shown if
available in the database. The data undergoes verification by Garmin to confirm
accuracy of the content, per TSO-C151c. However, the displayed information
should never be understood as being all-inclusive and data may be inaccurate.
TAWS-A uses information from the GPS receiver to provide a horizontal
position and altitude, along with additional altitude input from the radar
altimeter. GPS altitude is derived from satellite measurements. GPS altitude is
then converted to a height above geodetic sea level (GSL), which is the height
190-01004-03 Rev. F Garmin GTN 625/635/650 Pilot's Guide
Foreword
Getting
Started
Xpdr Ctrl
Com/Nav
FPL
Direct-To
Proc
Wpt Info
Map
Traffic
Terrain
Weather
Nearest
Services/
Music
Utilities
System
Messages
Symbols
Appendix
Index
10-37