Garmin Flight Deck 100 Manuel D’Utilisation
Embraer Prodigy
®
Flight Deck 100 Pilot’s Guide
190-00728-04 Rev. A
392
HAZARD AVOIDANCE
6.4 TAWS-A
WARNING:
Do not use TAWS information for primary terrain avoidance. TAWS-A is intended only to enhance
situational awareness.
NOTE:
Terrain data is not displayed when the aircraft is outside of the installed terrain database coverage
area.
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 designed 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. The displayed
alerts and warnings are advisory in nature only. When TAWS-A is installed, it supersedes the TAWS-B feature.
annunciations when terrain and obstacles are within the given altitude threshold from the aircraft. The displayed
alerts and warnings are advisory in nature only. When TAWS-A is installed, it supersedes the TAWS-B feature.
TAWS-A satisfies TSO-C151b Class A and TSO-92c requirements for certification.
Class A TAWS requires the following components:
• 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-C151b. However, the displayed information should never be understood as being all-inclusive and data
may be inaccurate.
shown if available in the database. The data undergoes verification by Garmin to confirm accuracy of the content,
per TSO-C151b. 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 the height above geodetic sea level (GSL), which is the height above mean sea level
(MSL) calculated geometrically. GSL altitude is used in part to determine TAWS-A alerts. GSL altitude accuracy
is affected by satellite geometry, but is not subject to variations in pressure and temperature that normally affect
pressure altitude sensors. GSL altitude does not require local altimeter settings to determine MSL altitude. It is
a widely-used MSL altitude source. Therefore, GSL altitude provides a highly accurate and reliable MSL altitude
source to calculate terrain and obstacle alerts.
altitude is then converted to the height above geodetic sea level (GSL), which is the height above mean sea level
(MSL) calculated geometrically. GSL altitude is used in part to determine TAWS-A alerts. GSL altitude accuracy
is affected by satellite geometry, but is not subject to variations in pressure and temperature that normally affect
pressure altitude sensors. GSL altitude does not require local altimeter settings to determine MSL altitude. It is
a widely-used MSL altitude source. Therefore, GSL altitude provides a highly accurate and reliable MSL altitude
source to calculate terrain and obstacle alerts.
The terrain and obstacle databases used by TAWS-A are referenced to mean sea level (MSL). Using the GPS
position and GPS-GSL altitude, TAWS-A displays a 2-D picture of the surrounding terrain and obstacles relative
to the position and altitude of the aircraft. Furthermore, the GPS position and GPS-GSL altitude are used to
calculate and “predict” the aircraft’s flight path in relation to the surrounding terrain and obstacles. In this
manner, TAWS-A can provide advanced alerts of predicted dangerous terrain conditions.
to the position and altitude of the aircraft. Furthermore, the GPS position and GPS-GSL altitude are used to
calculate and “predict” the aircraft’s flight path in relation to the surrounding terrain and obstacles. In this
manner, TAWS-A can provide advanced alerts of predicted dangerous terrain conditions.