Garmin 400-500 User Manual

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4
TIS Operation and Symbology
Section 1
TIS Symbology
TIS traffic is displayed on the 400/500 Series unit according to TCAS symbology, graphically displayed 
on a dedicated graphical page (Traffic Page; see below), and on the moving Map Page.  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).  All other traffic is displayed as a hollow white diamond.  Altitude 
deviation from own aircraft altitude is displayed above the target symbol if traffic is above own aircraft 
altitude, and below the symbol if they are below own aircraft altitude.  Altitude trend is displayed as an 
up arrow (>+500 ft/min), down arrow (<-500 ft/min), or no symbol if less than 500 ft/min rate in either 
direction.  
The TIS audio alert is generated whenever the 
number of Traffic Advisories on the 400/500 
display increases from one scan to the next. Limit-
ing Traffic Advisories only reduces the “nuisance” 
alerting due to proximate aircraft. For example, 
when the first Traffic Advisories appears on the 
TIS display, the user is alerted audibly. So long as 
a single aircraft remains on the TIS display, no 
further audio alert is generated. If a second (or 
more) aircraft appears on the display, a new audio 
alert is sounded. 
If the number of Traffic Advisories on the TIS 
display decreases and then increases, a new audio 
alert is sounded. The TIS audio alert is also gener-
ated whenever 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.
Own Aircraft
‘Other’ Traffic—This symbol represents 
traffic detected within the selected  
display range that does not generate 
a TA.
Traffic Advisory (TA)—This symbol is generated when traf-
fic meets the advisory criteria described on page 9.
Traffic Ground Track is indicated 
on the 400/500 display by a 
“target track vector”, a short line  
displayed in 45-degree incre-
ments.  This vector shows the 
flight direction of the traffic.