Garmin GNC 420 - Manual (Page 194)

GNC 420(A) Pilot’s Guide and Reference 11-4
SECTION 11
ADDITIONAL FEATURES
190-00140-20 Rev. K
TIS Audio Alerting
The TIS audio alert is generated when the number of
Traffic Advisories (TA) on the GNC 420 display increases
from one scan to the next. For example, when the first
TA appears on the TIS display, the user is alerted audibly.
As long as a single aircraft remains on the TIS display, no
further audio alert is generated. If a second (or more) TA
appears on the display, a new audio alert is sounded.
Limiting TAs reduces “nuisance” alerting due to
proximate aircraft. If the number of TAs on the TIS
display decreases and then increases, a new audio alert
is sounded. A TIS audio alert is also generated when TIS
service becomes unavailable. The volume, pitch, and
duration of the audio alert (including the choice between
a male or female voice) is configured during installation.
The following TIS audio alerts are available:
• “Traffic” - TIS traffic alert is received.
• “Traffic Not Available” - TIS service is not available
or out of range.
TIS Symbology
TIS traffic is displayed on the GNC 420 unit according
to TCAS symbology on a dedicated Traffic page, and on
the moving Map Page. The symbology is shown in Table
11-1 and Figures 11-2, 11-3, and 11-4. The symbology is
described in Table 11-2. A Traffic Advisory (TA) symbol
appears as a solid yellow circle (or half circle on the outer
range ring if the traffic is outside the range of the dedicated
Traffic Page). Other Traffic is displayed as hollow white
(may be configured as cyan) diamonds.
Altitude deviation from own (client) aircraft altitude is
displayed (in hundreds of feet) for each target symbol. If
traffic is above own aircraft altitude the deviation is shown
above the target next to a ‘+’ symbol. If traffic is below
own aircraft altitude the deviation is shown below the
target next to a ‘-’ symbol.
Altitude trend is displayed as an up arrow (> +500
fpm), down arrow (< -500 fpm), or no symbol if less than
500 fpm rate in either direction.
The traffic ground track vector protrudes from each
symbol in the approximate direction of travel.
Traffic Type Symbol
Traffic Advisory
Out-of-Range Traffic Advisory
Other Traffic
Table 11-1 TIS Symbology
Figure 11-2 Traffic Page
‘Own’ (Client)
Aircraft Symbol
‘Other’ (Intruder)
Traffic Symbol
Traffic Advisory
(TA) Symbol
Traffic Ground
Track Vector
Figure 11-3 Out-of Range TA Symbol
Out-of-Range Traffic
Advisory (TA) Symbol